Long-term readers may recall that the bankruptcy of hub gear manufacturer Sturmey Archer in the summer of 2000 left Brompton short of a suitable 5-speed hub. Other bike manufacturers migrated to the similar SRAM 5-speed, but the Brompton frame is unusually narrow, and it was not until May 2002 that the company came up with its own solution – the 6-speed (more correctly 2×3-speed) SRAM/Brompton derailleur/hub gear.

The new system took advantage of the Brompton chain tensioner. On a basic 3- speed hub-geared variant, the tensioner only moves when the bike is folded, but by fitting tensioner wheels designed to ‘float’ from side to side, it was possible to fit two sprockets side by side, doubling the number of gears. It all sounds a bit Heath Robinson, but engineered with Brompton’s usual attention to detail, the 6-speed soon established itself as a neat and efficient conversion.

The company decided to fit 13- and 15-tooth sprockets.The very similar sizes helped to give a slick gear change and resulted in evenly-spaced ratios.The bad news was a rather disappointing overall gear range of 215%, which was not much more than the 187% of the basic 3-speed. At 86″, top gear was the same, but first was reduced from 46″ to 40″. Just to recap, lower gears (measured in terms of the effective wheel size), give better low-speed hill-climbing, and high gears allow you to ride faster on the flat.

Fortunately, when the chain tensioner assembly was re-engineered for the 6-speed, the opportunity was taken to leave space for bigger sprockets, enabling the company to introduce the new 2-speed variant. Home tinkerers soon discovered that a sprocket as big as 18-tooth could be squeezed in, and paired with a 12-tooth sprocket, this stretched the gear range to 282%; better than most 7-speed hub gears.

…this stretched the gear range to 282%; better than most 7-speeds…

We tried a Steve Parry 12/18-tooth conversion in August 2002 and used it successfully for a couple of years until the 12-tooth sprocket shattered. As we had been warned, this was the weakness – the 12-tooth is so slim that it eventually cracks. A 13-tooth sprocket is stronger, but it reduces the gear range, and gives two pairs of ratios that are almost identical, resulting in a rather disappointing 4-speed.

Now, thanks to Highpath Engineering, the wide-ratio Brompton is back, and the new conversion seems to work very well.The basis is a combined 12/18-tooth sprocket assembly, the two components being tig-welded together, then re-hardened to give a reasonable working life.

Complicated Things

The first decision for those contemplating a gear upgrade is to calculate the sort of gears they want. Using Brompton’s 50- tooth chainring and the new Highpath sprocket set (£39.50), the standard gears of 40″, 46″, 55″, 63″, 75″ and 86″ become 33″, 46″, 50″, 62″, 68″ and 93″ – in other words, the high gears are higher and the low gears lower. Note that the fairly even spaces of the original have been lost, but as with the Sturmey Archer 8-speed (see A to B 40), we now have broad gaps at the extremities and narrower spaces between the middle gears, which can be useful.

If you’re looking for lower gears, you’ll need to fit a smaller 44-tooth chainring as well as the sprockets.This produces ratios of 29″, 40″, 44″, 55″, 60″ and 82″.Top is now lower than standard, but first is almost as low as a Speed Drive conversion! A new 44-tooth chainring costs £23.40, but if you’re planning to order a new bike, the option adds only £9.

For those without a 6-speed bike, a post-April 2001 3-speed (with the SRAM hub) can be upgraded to 6-speed spec for £78.40, but this would be a lot more expensive on an older Sturmey-geared machine.

A word of warning about chains, chainrings and widgets: for years Bromptons came with 1/8″ chain and 1/8″ chainrings (some are a little narrower), but since the arrival of the 6-speed the situation has become more complicated. Retro-fit 6-speed kits and a few early production bikes were supplied with 1/8″ chain, but all other 6-speeds will have narrower 3/32″ chain.The standard 50-tooth, and smaller 44-tooth, chainrings have been produced in both chain sizes, although Brompton expects to standardise on the narrower 3/32″ soon.The wide-ratio kit will work with an 1/8″ chain, but we’d strongly recommend 3/32″. A 1/8″ chain will run on either chainring, but a 3/32″ chain will only fit a 3/32″! Before doing anything, it’s a good idea to try a new piece of 3/32″ chain on your chainring and see what happens – if it fits, great, if not, you’ll need a narrow version.

If in doubt, renew anything that moves, because the new sprockets ask a lot more of the changer mechanism. It’s good practice to use Brompton chain, because the nominally 3/32″ chain pin length can vary, and not all work happily in the Brompton derailleur. If your eyes are glazing, simply trot down to a hub gear expert, such as Bicycle Workshop of West London (tel: 020 7229 4850) who will solve all the technical bits.

Fitting

A 5mm drill soon gets the bearing spinning again

The inside face of the rear frame tube must be ground back to clear the 18-tooth sprocket.

Note how filthy the tubes can get...

Changing the sprockets is easy, but if working on an older bike, you’ll need to check that the system is working properly first. Remove the rear wheel and chain, and flick the gear changer back and forth whilst observing the ‘chain pusher plate’ at the rear end. If the operation seems sticky or unreliable, release the cable assembly and try moving the pusher plate by hand – any tightness or roughness will have to be sorted before you go any further. On early ball-bearing units, in particular, the bearing will almost certainly need to be thoroughly cleaned or replaced.

With the spring clip popped off the hub, and the old sprockets removed, the new sprocket assembly will slide into place after refitting the original dust shield and the new shims. At this point things get a bit more difficult, because it’s necessary to remove a few millimetres from one of the rear frame tubes to clear the teeth of the larger sprocket.We did this by gently squeezing the tube and grinding away the last millimetre or so.

…Fitting the sprockets gives the Brompton… a gear range similar to a typical hybrid…

With the dodgy bit out of the way, all should now be plain sailing.With the rear wheel in place, feed in a new 98-link (100-link for a 50-tooth chainring) x 3/32″ chain and connect it up. As the new 18-tooth sprocket fits slightly outboard compared to the standard 15-tooth one, the chain pusher plate will need adjusting. Disconnect the cable assembly from the pusher plate, and move the plate by hand as far as it will go, checking that the plate either gently touches, or just clears the chain at each extreme. If it needs adjustment, turn the relevant stop screw until you’re satisfied that the pusher plate is just going far enough to change gear smoothly.

Finally, reconnect the cable assembly, turn the bike upside down (or get someone to lift the rear frame) and try changing up and down through the gears.The 2-speed changer gives twice as much cable movement as is required to change gear, so it should work well enough, even when slightly out of adjustment. If one or other of the gears is failing to engage properly, remove the trigger cover and move the outer cable to another of the four location slots until both gears engage smoothly and cleanly.

In Use

The most noticeable thing is the very different characteristics of the two sprockets: the 18-tooth feeling silky-smooth and the smaller 12-tooth relatively ‘coggy’.The change quality is a little lumpier than standard too, but it should remain crisp and fast – obviously new components will cope better than well worn examples.

In normal riding, we tend to stay in the top range, using the top two gears. As a steep hill approaches, the change from middle gear/top range to top gear/low range is one of the closer ones, but it sets the bike up for more serious climbing. Over the top, and it’s back into the high range and up to top gear. Being slightly lower than standard, top does tend to run out of steam on the descents, but for most people this will be a small price to pay for the much lower gears.

A really steep hill will defeat the bike, even with a 29-inch bottom gear, primarily because the front wheel begins to lift as you pedal – in any event, walking may now be quicker. In all other circumstances, this is more or less a go anywhere Brompton.

Conclusion

Fitting the 12/18-tooth sprocket block takes a few hours, but it’s a cheap, light and effective solution, giving the Brompton a gear range similar to that on a typical hybrid. Efficiency is better than a 7- or 8-speed hub, and although the double changers may seem confusing, the system is no more complicated to use than a 3×7 derailleur.

How long will it last? As our prototype has done only a few hundred miles, it’s hard to judge.The 18-tooth sprocket should last forever, but the 12-tooth will have a relatively short life, and of course, when it eventually fails, you’ll have to throw the whole assembly away.We would expect to see 2,000 miles at the very least, and 3,000 miles or more with care. Given the relatively low purchase cost, that sounds quite acceptable against the alternatives, and would equate to many years of leisure use.

Brompton 12/18-tooth block £39.50 plus postage of £3 (UK), £7 (Europe) or £15 (worldwide) . Manufacturer Highpath Engineering tel/fax 01570 470035 mailadmin@highpath.net

A to B 47 – April 2005

Crikey. This is all beginning to sound a bit like the comedy sketch (one of several) where the innocent man goes into the shop and asks for a record player, and is mercilessly ribbed by the spotty youths behind the counter. Ask for a folding bicycle these days, and you’ll be laughed back onto the pavement: ‘With or without the titanium crown-fork assembly, sir?’ ‘Hub, dynamo or battery lights?’ ‘Pentaclip or traditional clamp?’ P-type bars?’ With or without Stelvios?’ And so on through the gear options, ad infinitum.

The high riding position is slightly more upright than the classic Brompton.

For those with plenty of money, the easy answer is to opt for the P6R- XDL. Assuming you’ve had the foresight to jot the code number on the back of an envelope, and you have a cool £1,225 in your pocket, you can walk out of the shop with just about every option and cut out the tiresome discussion.

We’re being flippant, of course, but no doubt some people will buy this top of the range model because it’s the most expensive option and thus (hopefully) the best that money can buy. But is it? That depends what you want. The P6R-XDL is aimed at cycle tourists and professional folding bike users: the Sustrans Rangers, map-makers and surveyors for whom a folding bike is a work station rather than a means of getting from A to B.

T6 to P6

The core of the machine is the current T6: rear rack, six gears, dynamo lights, and front luggage. Under the skin the bike is very different, but the most striking difference is the odd rectangular handlebar assembly.This looks ludicrous at first glance – the sort of geeky accessory fitted by earnest types searching for an extra 0.1mph on the Great North Road. But please do put your prejudices away for long enough to try it, because the P-type handlebar works really well.

Like drop-handlebars of old, the bars give you two very different riding positions: high for traffic, and low for fast riding in open country. At 104cm from the ground, the top riding position is ideal for city use, with the brake and gear levers immediately to hand. Once out of town, the idea is that you move your hands down to the lower position, where the bars are shaped like the turned-down bars favoured by scorcher cads at the turn of the 20th Century. At 89cm or so, these lower bars reduce your frontal area, giving a comfortable and wind- cheating position.

Unless the roads are seriously empty, you shouldn’t relax too much in this position because the gears, and more importantly, the brakes, are now a long way from your fingertips.Whether sleepy P-type riders will start ploughing into stationary buses remains to be seen. After a while on the ‘drops’ you tend to forget and reach for the brake, then realise your mistake and change position. This process takes a few heart- stopping milliseconds. Otherwise, the system works well, the two primary positions and myriad alternatives giving relief from aches and pains as well as headwinds.

Interestingly, the difference in frontal area seems to make quite a difference to the roll-down speed. Riding in the low position and attempting to create a good wind- cheating shape, we recorded a speed of 15.9mph – a whisker faster than the slightly more upright S2L-X. Holding the bars in the top position, rolling speed drops back to 14.7mph; a huge difference.The differential would probably be of little consequence in town, but at higher speed, the new bars will have quite a big effect.

…high for traffic, and low for fasty riding in open country…

The other major design feature of the P6R-XDL is the same titanium kit used on the lightweight bikes. In this case, the chunky rack and other accessories rule out a headlining weight, but at 12.1kg, the bike is still a little lighter than its predecessor.

On the road, the machine rides broadly like a traditional Brompton.The only downside for those expecting to scale the Himalayas is the narrow gear range of the Brompton 6-speed, which remains unchanged.There are a number of upgrades around, of course, from cheap and cheerful Highpath sprockets to a pricey but capable Mountain Drive, but it seems odd that Brompton has not engineered a solution of its own.This bike does deserve more gears, or at least, a wider range.

…professionals will choose their own spec from the long list of options…

Interestingly, this top-end model comes with Brompton’s own cheaper ‘Green Flash’ kevlar tyres rather than the Schwalbe Marathons fitted to the cheaper P6R-PLUS. If you keep in touch with Professor Pivot’s musings, you will know that we’re not overly-keen on any of the kevlar-reinforced options, but this tyre is at least cheap and pretty light.

Which brings us to illumination. If you’ve had enough of seized dynamos, broken wiring looms and faulty bulbs, the lighting package on this bike should help to get your night-life sorted.The rear lamp is the familiar stand-light version of the Basta LED used by Brompton for several years, while the front is a Basta Ellipsoid halogen.This pair are powered by the new narrow version of the SON hub dynamo, designed specifically for small- wheelers.This delightful thing is controlled by an equally small (and rather inaccessible) switch on the back of the front light.

Surprisingly, the difference in frontal area is barely 1%, but the lower position makes a more streamlined shape, while the upper position is more comfortable!

With the switch off, the rolling resistance of the dynamo is almost unnoticeable.Turn it on, and the lights work well, right down to a walking pace. Rolling resistance increases, but in terms of roll-down speed, the difference is barely noticeable.We can’t claim that the wires won’t break or connectors drop off, but the basic hardware is very good indeed and should work effortlessly and quietly for years.

Other Accessories

With Brompton’s mix-&-match policy, published spec gives no more than a guide. If you don’t want the SON hub dynamo, you can choose a lighter bottle dynamo, or battery lights, or all three, or nothing. Similarly with luggage: the P6R-XDL will accept any of Bromptons range of four front quick- release bags, although there is a one small proviso with this handlebar pattern: if you fit the front battery light, it will be obscured by all but the new lower S-bag.

For the rear rack, Brompton and Radical have come up with a neat bag which – in marked contrast to the S-bag, which has a tardis- like interior – looks huge, but holds only 17 litres (slighter more than the old Pannier bag, but rather less than the Touring bag). That said, it more or less doubles the bike’s carrying capacity, so it will have its uses.

Conclusion

One thousand two hundred and twenty five quid sounds a lot of money. All right, it is a lot of money, but in this case it buys an awful lot of technology. For that sort of amount you could have a Birdy Black, which weighs about the same with a similar accessory pack, provides a bigger gear range, but folds into a much larger package. Otherwise, we’re well into Moulton/Bike Friday territory; machines that can’t compare folding-wise, but offer legendary performance. In this company, the real strength of the P6R-XDL is that it combines the folding ability of the Brompton with reasonable weight and decent equipment. The feedback we’ve had is that professional users wouldn’t go for the P-type bars (‘not really that keen’) or the lightweight components (‘didn’t notice it’). But in this market, reliability is paramount, so users will happily pay big money for such extras as SON hub dynamos, hub brakes (not yet an option) and puncture-resistant tyres. It seems the professionals will choose their own spec from the long list of options. Our prediction is that they won’t go for the P6R-XDL, but for cycle tourists, reduced weight and alternative riding positions are more important.

Specification – Brompton P6R-XDL

Brompton P6R-XDL £1,225 . Weight 12.1kg (27lb) . Gears Brompton/SRAM 6-spd Ratios 40″, 46″, 55″, 63″, 75″ and 86″ . Folded Dimensions W29cm L58cm H58.5cm Folded Volume 98.4 litres (3.48 cu ft) . Manufacturer Brompton Bicycle tel 020 8232 8484

A to B 47 – April 2005

Something has been up at Brompton for months. Little snippets of information have leaked out, but the dead giveaway was the report that a group of Russians had been spotted in the Brentford factory discussing strange grey metal objects. They obviously weren’t selling vodka, said our contact. The metal could only be titanium, and the Russians just had to be negotiating to supply it. It turns out that the rumours were largely true – Brompton has made arrangements for the fabrication and supply of a number of titanium parts from both Russia and China (you can’t be too careful these days). Initially, these parts will be fitted to a range of new expensive models, but the technology should gradually trickle down, bringing a new era of lighter, more durable folding bikes.

Brompton describes its 2005 model changes as ‘greater than anything we’ve done since the Brompton was first introduced 17 years ago. We can’t argue with that. For well over a decade the Brompton has set the standard in terms of foldability and compact folded size. But, as we’ve often said, the classic Brompton is relatively heavy, and although it’s a rigid and practical machine, for some people the odd handlebars and low-slung frame present something of an image problem.

We’ve made suggestions over the years to broaden the appeal, as have many others, and the company has at last responded with a Big Bang upgrade to be rolled out from May this year. We’ll try and keep things simple, but this being Brompton, the options are legion and the technical wizardry complex. As a measure of just how complicated the picture has become, the range of five bikes has been extended to ten, and there are numerous other options, special options, and under- the-counter options for very special customers.

The good news for traditionally-minded folk is that the old C, L and T-types remain on the books, and at similar prices.The C type becomes the C3E at £380, the L3 becomes the M3L at £480, and the T6, M6R-PLUS (yes, R for rack) at £635.The C still comes in red, but in true Henry Ford style, the M3L and M6R will be available only in black with silver forks and rear frame. If you really want a 6-speed L, or a 3-speed R – or any colour other than black – you can have it, but you will have to pay for a special build machine.

…the old C, L and T-types remain on the books at similar prices…

Beyond this basic range, things get a bit complicated, because the company has gone for choice, choice, and more choice.

Superlight Bikes

The lightweight bikes feature a range of new bits, principally titanium (seat pillar, front forks, rear frame assembly, mudguard stays and folding pedal bolt) in various combinations, a simple 2-speed derailleur (as seen on the current 6-speed), lightweight saddle, and lower, flat handlebars on a slightly taller stem.

The basic lightweight bike is the S2L at £560.This has the new handlebars and 2- speed gear system , but none of the pricey bits. A good option if you are looking for a simple, reliable and slightly lighter about town machine. The commuter version is the S6L-PLUS (£735), with six gears, new slightly lower front luggage (we’ll come back to this) and battery lights – an updated L6, if you like. The standard colour for these bikes is all-over black, unless you are minded to pay £25 or more for one of the colour options.

Current Brompton range on the left, new range on the right. Most current models remain in production at slightly lower prices after inflation, but any colour other than black/silver now costs extra. The new titanium-based machines take the Brompton into a whole new price zone.

Lightest and sexiest of the lightweight bikes are the superlight machines – M2L-X and S2L-X, available in a choice of three pastel matt finishes (blue, green or pink) to compliment the natural titanium scattered liberally about the machines.The M2L-X is basically a two-speed version of the old L-type, but with most of the titanium bits on board to reduce weight. At £873, this sounds a practical solution for those who need a significantly lighter bike at reasonable cost.  Lightest of all (unless you special order a single speed) is the S2L-X, with the straight bars, all the titanium kit, Vitesse saddle and Schwalbe Stelvio tyres. At £965, this bike comes in just under the psychological £1,000 barrier and weighs a head-lining 9.7kg. That’s a kilogram heavier than the Dahon Helios SL we tried last year, but the Brompton has mudguards and a front luggage block, so it’s better suited to regular commuting, should one be so inclined.

The titanium rear frame, seen here on the P6R-XDL, is significantly lighter.

Brompton has decided that the flat-handlebar S-type machines should only be fitted with the S-Bag, a new lower but deeper front bag made by Radical. We’ve tried the conventional bags on the S-type, and provided they’re not over-filled (a problem on any variant), there’s little risk of the bag fouling the bars. On the other hand, the S-bag is just as spacious as the standard Pannier; both holding 16 litres of water, measured by the Archimedes principle (bin- liner in bag, bag in bath, boy fills bag with water and records result in Handy Tablet notebook).

High-spec P-type

For some users, of course, quality equipment and touring capabilities are more important than weight.To this end, Brompton has developed an extraordinary new handlebar, giving a choice of seating positions – upright, as on the old bikes, or dropped.The bars are similar to the Bike Friday H-bars, but in a vertical plane.This is the ‘P-type’, and there are several options, all in black/silver as standard.

…For some users, touring capabilities are more important than weight…

Brompton's own brake design is being launched on the 'P' and 'S' type bikes, but will probably become universal. Note the reach adjuster.

Cheapest is the P3L, exactly the same as the M3L, but with the new handlebars for an extra £35. Next up is the P6R-PLUS, at £807. This bike comes loaded with the sorts of accessories a serious user might specify – six gears, Schwalbe Marathon tyres, dynamo lighting, better saddle, plus the titanium seat pillar and folding pedal axle to keep the weight under control. Disappointingly, the gear range is no wider than the current bike, although this variant is clearly aimed at cycle tourists and others.We’d guess that many owners would want to upgrade to either the Mountain Drive gear system or wide ratio sprockets (see page 27).

Top of the range, and most expensive by a fair margin, is the P6R-XDL, at £1,225.This comes with a full complement of bits, including a neat and effective SON hub- dynamo and all the titanium, bringing the weight back down to a respectable, but not very exciting, 12.1kg. All the same, it’s technically in the superlight category, so the XDL is available only in the three special colours, unless, of course, you specify something else.

Other Changes

The Hermanns battery light option - quite powerful and weighing only 100g

Got all that? The first figure (C, M, P or S) depicts the model type (generally identifiable by the handlebars); the second (2, 3 or 6) the number of gears; and third is the version – E for Economy, L for Lightweight (ie no rack), and R for Rack. But the ten ‘standard’ models are just the tip of the option iceberg, because just about any parts can be specified on just about any bike, and there are a number of other choices.

As we’ve seen, most of the standard bikes now have a black mainframe, although any of last year’s colours can be specified for a surcharge.This sounds a bit unfair, but prices have generally risen by less than inflation, which softens the blow.

Aqua Blue has been dropped and replaced by the post-apocalyptic Raw Lacquer, which like the Lloyd the Building, puts all its structural innards on display. This is a more expensive option, mainly because the parts will be hand-picked to show off the neatest brazes… The exposed tubes might well compliment the natural titanium on the pricier models, but then they might not. Do let us know.

…the exposed tubes might well compliment the natural titanium…

An option requested by some regular users is taller, thinner  ‘rollerblade’ rear rollers. Brompton has responded with rubber-tyred, ball bearing ‘Eazy-wheels’. A pair of these slightly taller wheels can be fitted to any bike, but the company says they work best as a set of four on the R-type. Apparently they are not narrow enough to please those whose ankles hit the standard rollers.

Lighting has seen a lot of development.The Basta rear LED is unchanged, but the former rather feeble battery front light has been replaced with a 3-LED Herrman unit. This is similar to the Jos Star Tube, but more rugged and with greater light output, says Brompton. Weight, complete with 3 x AAA batteries, is a minimalist 80g, plus 20g for the mounting bracket. The light has a quick-release, so you’re supposed to stick it in your pocket when folding the bike, but an alternative game plan is to swing the bracket around on the bars, leaving the light in place.

LED front lights are not strictly legal as a primary lighting source in the UK, but the wheels of official favour appear to be grinding in the right direction, so they soon will be. The Herrman produces an unusually tightly focussed beam – smaller and less bright than the bigger and heavier Cateye EL500, but twice as powerful as ‘first generation’ lights, such as the Cateye EL200. It’s adequate as a sole light source on all but the most demanding country roads, but must be carefully aimed to put the narrow beam in the right place, and (very common this) the reflector throws back stray light, which can be annoying in dark conditions.

Those with a preference for dynamos can choose between the current AXA HR bottle dynamo, or the newly developed narrow SON hub unit. Not cheap, but the ultimate for those who want simple, reliable and effective lighting.

…the developments seem to have put the bike back at the cutting edge…

The Easy-wheel rollers make the folded package easier to roll, but despite appearances, are no narrower.

Gear options remain the same, but any bike can be specified with the new 2-speed (or a basic 1-speed variant), and the larger 54- tooth chainring from the two speed can be specified on hub- geared bikes, giving an 8% higher gear option. Elsewhere, the handlebar clip has finally (and, we hope, permanently) been strengthened with a spring steel hairpin affair, to be fitted to all models – not before time. The Vitesse Eazy-wheel rollers make fi’zi:k saddle (standard the folded package easier to on the pricier roll, but despite appearances, are no narrower models), certainly looks sporty, and feels comfortable. If you think it’s any old fi’zi:k, think again, because this being Brompton, the saddle rails have been extensively re-engineered. Brompton has also developed the Pentaclip micro-adjust saddle clamp, initially for the optional saddles, but no doubt this will become universal at a later stage.

Retrofitting

Good news for those who want to upgrade an older Brompton, is that many of the parts will be available separately, and most new parts will fit most older Bromptons. The titanium seat pillar, Pentaclip clamp and Vitesse saddle are a straight swap, taking only a few minutes and saving 380g at a stroke.The relocated and strengthened saddle rails help to produce the smallest possible folded size, but add some weight, so you can knock another 80g off fairly easily with a less exacting design.The Pentaclip is excellent for anyone fitting a railed saddle to a Brompton, or indeed any bike with a 22.2mm seat pillar.Weighing only 90g, this little masterpiece of engineering gives hassle-free adjustment.

The Pentaclip doesn't sound very exciting, but it is a great advance - no Brompton should be without one

Current owners might also consider fitting the titanium folding pedal axle (saving 26g), or mudguard stays (unspecified weight saving, but instant one-upmanship). Changing either the rear frame, front forks or handlebar stem is probably more trouble than it’s worth, but these can all be done at a price. More realistically, the new battery front light is a useful option, as are the Eazy-wheel rollers and the new lower S-Bag.

Conclusion

These are obviously enormous changes, and Pentaclip doesn’t sound it’s hard to judge just how successful the very exciting, but it is a great different models will be. Our money is on the P6R-PLUS. advance – no Brompton should At £807, this seems to offer most of the equipment be without one serious users have been asking for, although we’d probably specify the SON dynamo to complete a tough and reasonably light package. At the lighter end of the spectrum, the M2L-X comes with most of the weight-reducing elements fitted to the more expensive bikes, but at £873, it’s a little cheaper, and it looks more conventional – important to some people.

We’ve heard rumours that Dahon’s 16- and 20-inch extra lightweight bikes have been selling slowly, which we can’t confirm because the company has gone strangely quiet. If it’s true, how will the heavier, but more practical Brompton lightweights fare? We have no idea, but the next few months will no doubt reveal a great deal.

Whatever the winners and losers, the developments at Brompton certainly seem to have put the bike back at the technological cutting edge, after many years of sensible, if rather uninspired development. Congratulations to Andrew Ritchie, chief engineer William Butler-Adams, and marketing manager Edward Donald on a remarkable achievement.

The new Brompton range will be available from May. Brochures and full details from Brompton Bicycle
tel 020 8232 8484

A to B 47 – Apr 2005

Long ago, we built a lightweight Brompton, wrote up the saga in A to B 7, and went on to sell hundreds of extra magazines. We’re still producing photocopies today, which told us something, and maybe Brompton took notice too – there seemed to be interest in reducing the weight of the bike.With hindsight, we did rather well; our fully-equipped 3-speed Brompton tipping the scales at a shade under 10.5kg (23lb), including a front luggage block, mudguards, rear LED and even toe- clips.

Almost seven years later, Brompton has produced its own lightweight machine. It’s more expensive, and a 2- speed rather than a 3-, but the new S2L-X weighs only 9.7kg (21lb), making it one of the lightest folding bikes in current production, and certainly the lightest Brompton ever produced. If you find the Brompton heavy to carry, this may be the machine for you, but are you willing to pay £965? For Brompton, we doubt whether the opinions of creaky old fogies like us are of any importance, because this chic, hi-tech bike will be aimed at younger people (all the brochure models are under 30), with particular emphasis on young women.

…Brompton needs to attract the sort of people who wouldn’t be seen dead on a Brompton…

Will this lighter, but very much more expensive, bike really appeal to a whole new generation of 20-something professionals? We think Brompton is right to aim for this group, because – if you haven’t noticed – the demographic of cyclists is becoming more and more decrepit. If the folding bike market is to survive and grow, Brompton needs to attract the sort of people who wouldn’t be seen dead on a Brompton. It’s a tall order.

The S2L-X

Narrower, lighter Stelvio tyres

To the untutored eye, the S2L-X is a conventional folding bike.The only unusual bits are straight handlebars, and an odd paint job: Flamingo Pink according to Brompton, but anyone with experience of school dinners in the 1960s and 70s will recognise ‘school blancmange’. Look more closely, and there are other differences: the decal is a designer job, the saddle is sportier, the front forks and rear frame are made of titanium and the bike has narrow Schwalbe Stelvio tyres and a 2-speed derailleur. Look very closely indeed, and you may spot the titanium mudguard stays, new brake levers and alloy headset.There’s lots of technology here, but it only really becomes apparent when you pick the bike up, because it weighs 9.7kg, against 11-12.6kg for the normal bikes.

…other traffic will already be braking, putting the nifty shifter back up front…

Titanium front forks

Jump on, and the feel low and very rigid.The lack of gears doesn’t seem to be a hindrance, because what the bike loses in ratios, it gains in rigidity – the straight bars being much less flexible than the old ‘violin case’ design. By fitting the standard 2-speed derailleur with 12- and 16-tooth sprockets (in place of 13- and 15- tooth), Brompton has given the S2L two well chosen ratios of 56″ and 74″, which one might equate as ‘starting gear’ and ‘riding gear’.With gears like these, you won’t climb any mega-gradients or spin along at 20mph, but the bike copes with hills of up to 10% and – thanks to the lighter rotating bits and single slick gear change – it accelerates well, easily outpacing more cumbersome bikes up to 14mph.Thereafter, the lack of gears begins to tell, but in most city conditions, the other traffic will already be braking for the next traffic lights, putting the nippy shifter back up front. Remember too, that a simple 2-speed derailleur is more efficient than a hub gear.The result is a machine that really demands to be ridden hard and responds well.

…the derailleur slips easily and slickly between the two gears…

We were a little disappointed with the Schwalbe Stelvio tyres when they came out – not because they were slower or heavier than the cutting edge products, but because they were less sturdy without being notably faster or lighter.We questioned whether a weaker tyre was worth fitting for such a small gain. Brompton has clearly decided that it is, claiming a weight saving of 140g (presumably with lighter Schwalbe tubes as well) over the standard Brompton tyres.We didn’t find quite such a big differential, but we’d agree that the Stelvio is the lightest tyre available, albeit by a narrow margin. Brompton makes two cautionary points: avoid using a bottle dynamo, which is liable to shred the sidewalls, and keep the tyre pressures above 85psi or heavier riders will risk ‘pinch punctures’. Otherwise, these tyres are fast, reasonably comfortable (only fatties will need the full 120psi), and light. Aided by the low riding position, 80/100psi in the tyres, and a nice warm spring day, we recorded an excellent 15.4mph roll down speed – one of the fastest runs we’ve seen with 16-inch tyres.We only had time for a few runs, so this figure won’t be very precise, but it’s worth bearing in mind that all three of the folding bikes reviewed in this issue were tested together, so comparisons are certainly valid.

2-speed derailleur. Note the standard Brompton tensioner arm and new free hub

The derailleur slips easily and slickly between the two gears, which are further apart than the standard Brompton 6-speed, but closer – and thus smoother changing – than the Highpath Engineering conversion. Incidentally, anyone intending to take an angle grinder to their new titanium frame in order to fit the Highpath wide ratio cogs will be wasting their time.The 2-speed has a special 9-splined hub which is incompatible with anything else.That’s a shame, because we think some users would prefer a slightly lower first gear, even at the expense of a bigger jump between the two ratios.

Braking feels odd, despite the bike being fitted with familiar dual-pivot callipers.The new Brompton levers obviously impart a different feel, as do the Jagwire cables.We’ve found these super-slick elsewhere, but the cables seemed stretched on this bike, giving a sticky response, particularly at the rear. There’s no fundamental reason why such good cables should bind, so we assume everything will be sorted for production.

Folding, Adjustment & Accessories

Apart from the handlebars, the machine looks fairly conventional

We won’t say much about folding, because the procedure is the same as a traditional Brompton, but once you’ve folded it, 9.7kg is obviously easier to carry than 12kg. Most people find a standard Brompton hard on the arms when crossing a railway bridge or marching between Underground platforms, but this bike is noticeably easier.The same applies when popping up and down stairs – you find yourself doing things with the S2L that you found ways of avoiding with other folding bikes. Folded size is a little larger than previous Bromptons because the comfy new Vitesse saddle is longer.With the saddle right down, we made a cube of 92.3 litres (3.3 cu ft), but the package gets bigger if you put the saddle at the top of its post and/or adjust it backwards, which lengthens the folded package and increases the volume to 105 litres (3.7 cu ft) or even more.To put that in perspective, it’s still 33% smaller than the Mezzo…

Is the bike really going to appeal to the iPod generation? We haven’t seen Tempest Blue or Kew Green (a nice local touch for a West London factory), but Flamingo Pink only seems to hit the spot under the right lighting conditions. In bright natural light, the matt finish and subdued hues can look washed out and lacklustre, but in the right sort of artificial light, the bike really sparkles. More generally, the combination of grey titanium, blue titanium (the seat pillar is treated to reduce scuffing), various shades of silver and shocking pastel pink may or may not appeal.

Once out of the showroom, those with smaller hands should be able to find a comfortable riding position. At long last, Brompton has come round to providing brake levers which are adjustable for reach, but with these handlebars, the levers have to be positioned vertically to prevent a clash with the front wheel when folding, or the front luggage when riding.

As mentioned elsewhere, luggage does pose a few problems. Brompton uses a standard frame-mounted carrier block which takes three sizes of luggage.These clear the standard handlebars (and the new P-type bars), but tend to restrict the brake cables on the S-type and if over- filled, could foul the handlebars. In practice, the standard Brompton Pannier and folding basket do fit, although it would be wise not to over-fill either. Playing safe, Brompton has introduced a new lower bag (and special low frame) called the S-bag. Produced by Dutch company Radical Design, the S-bag weighs 1.1kg – a little heavier than the Pannier, but lighter than the humungous Touring bag.The S- bag overflows with fashionable zips, pockets, ‘beam me up Scotty’ communicator holsters and all the other accoutrements of modern living. If you don’t hold with such style-things you’re probably the wrong person to be riding the S2L-X anyway. Naturally, the more fashionable youngsters loved the S-bag.

…We’ve seen lighter bikes, but none of them were practical commuters…

Like all new Bromptons, the S2L has a longer frame, so if you’re used to the old model, you’ll find a welcome centimetre or two of extra length here.The Pentaclip fixing also allows the saddle to go a little higher than the old fitting: up to a maximum of 97cm, which should make life easier for those who would consider themselves just too tall for a standard Brompton seat pillar. On the other hand, the handlebars are fixed at a relatively low 92cm (9cm lower than standard).We found that almost everyone who knew and liked the conventional Brompton said they preferred the old handlebars. On the other hand, there may be thousands of others who have rejected the conventional Brompton on the same grounds.They’re the people this bike needs to appeal to.

Conclusion

We’ve seen lighter bikes, but none of them were practical day-to-day commuters, which the S2L certainly is. Sub-10kg bikes don’t generally come with mudguards or luggage carriers, and in most respects this is a conventional Brompton, capable of doing just about anything a conventional Brompton will do. Once you’ve taken a deep breath and paid for it, titanium should last for many years without corroding or failing. Our only concern is with the surface treatment on the seat pillar, which seemed to show signs of mild scuffing after a week or two of fairly intense use.

Competition? The Dahon Helios SL is both lighter, and at £800, cheaper, but it’s hardly equipped for a daily commute, and we’ve heard a few grumbles about spoke problems. Dahon also produces the little Presto Lite, which is claimed to weigh 8.9kg, even in 3-speed form.We can’t verify this because we haven’t tried the bike, but at £570 (currently discounted to £520 or less), it’s a lot cheaper than the S2L.

Competition comes from within the Brompton stable too.We suspect many will opt for the M2L-X, which is £92 cheaper, almost as light, and with the advantage (for some) of more conventional upright handlebars.We’re very, very tempted.

Specification – Brompton S2L-X

Price – £965
Weight – 9.7kg (21lbs) .
Gears – Brompton 2-speed derailleur . Ratios 56″ and 74″ .
Folded Size – W27.2cm L58cm H58.5cm .
Folded Volume – 92.3 litres (3.26 cu ft)
Manufacturer – Brompton Bicycle tel 020 8232 8484

A to B 47 – April 2005

Like the Routemaster buses featured last month, new folding bikes seem to arrive in groups of three.This is awkward for those who make a living testing bikes, and bad news for manufacturers too, because if the Mezzo had not been overshadowed by this month’s news from Brentford, it would have been very big news indeed.The Mezzo is a completely new folding bike: all alloy, 16-inch wheels, up-to-the-minute British design, and manufactured in Taiwan to keep the price within three figures. By any standards, that’s big news.

Gestation

To find the origins of the Mezzo, we need to go back a number of years. For some time, a British company called ATB Sales has marketed Marin bicycles in the UK. Actually, the Marin bit only accounts for 85% of ATB’s turnover, because as any mountain bike enthusiast will know, ATB employs Jon Whyte, and Mr Whyte is the designer behind the Whyte range of top-end mountain bikes, produced for, and marketed by, ATB Sales.Whyte also engineers some  clever suspension designs for others, notably Marin, so this is clearly more than just a ‘Marin UK’  operation. Most British ‘manufacturers’ have offices on Junction X of the M6, staffed by bored over-weight sales-suits, but ATB has real design premises, staffed by real skilled people.This element is obviously of some importance to our story.

…this is clearly more than just a ‘Marin UK’ sort of of operation…

Five years ago, Jon Whyte produced the PRST1 or ‘Preston’ front fork. Apparently, the fork bears a passing resemblance to Preston, the fiery mechanical dog from Aardman Animation’s ‘Close Shave’. After sales of more than a million pounds, PRST1 spawned a folding mountain bike design exercise that turned into a full working prototype in 2000. We were lucky enough to see this extraordinary ‘praying mantis’ machine; heavy and unwieldy, but offering loads of gears, a conventional wheelbase, and full suspension. A bit impractical, but the lineage was clear – unlike most other folders, it was designed to appeal to the trend-conscious and wealthy young men buying top-end MTBs.

The trail then went cold for a few years, but ATB was busy behind the scenes, pouring money (some say £300,000) into an entirely new folding bike design.The key criteria were 16-inch wheels (the larger 347mm British kind, rather than 305mm Far Eastern), automatic folding catches, and (like the Birdy) a rigid hinge-free frame.To keep weight and complication to a minimum, the bike would have no suspension – unusual for a 16-inch machine.

In late 2004, the first hand-built prototypes were shown at the London Cycle Show, but manufacture took some time to arrange, and the first 50 or so production bikes have only recently been distributed to selected and trusted Whyte outlets. Sales aspirations are low for now – and expected to remain so against UK Marin sales of 23,000 last year – but ATB will ramp up production once the design has been de-bugged.

The Mezzo

Our test bike is an early production machine, so the spec is bound to change. It will be interesting to see whether our predictions as to where it should change prove correct. First, the frame.The Mezzo has a smart alloy frame, shot-peened to a rough matt finish, and topped with smart modern graphics and gunmetal grey anodising (silver will follow as an option). In terms of both product design and finish, it’s superb, and in a different league to the tasteless, and sometimes rather gormless Chinese things that usually fall out of the box. This is one of the first folding bikes with a proper design pedigree, and it really shows. In terms of looks.The only slightly questionable area is the strangely cranked handlebar stem, of which more below.

On the road, the deep oval monotube frame is stiff, but opinions vary as to the handling. Most people found the bike twitchy and unpleasant at first, particularly when accelerating hard. Quite why this should be, we’re not sure.The sub-100cm wheelbase doesn’t help, and the  handlebars are some way forward of the steering axis, which imparts a rather odd feel. Other more complicated things like trail and steering angles can have an effect too. Suffice to say, it feels a bit strange.

 …13.3mph – headline stuff in the small wheel Dark Ages, but well below average today…

Once you’ve acclimatised, you can ride a bit harder. Even standing out of the saddle results in no obvious frame twist, although the handlebars and the convoluted stem can flex under duress. But that’s only in contrast to the general rigid feel of the bike – it’s still better than average in folding bike terms.

Wheels and tyres are 349mm, as on the Brompton and Micro.This is great news, because it means a really compact package.There’s also plenty of technology in this size, giving a choice of low weight, high performance and long life (some tyres, arguably, providing all three). Unfortunately, the Mezzo’s smart-looking, custom-made Cheng Shin tyres seem to be some way off the cutting edge. Supplied only in 55psi kevlar-reinforced form, the tyres are light, but rather sluggish, and a bit of a disappointment on such an ostensibly sporty bike.

Rolling speed on our test hill came out at 13.3mph, which would have been headline stuff back in the small-wheel Dark Ages, but is well below average today. Normally with a new tyre we’d try a few experiments with tyre pressures and temperatures, but with maximum pressures of 55psi, there didn’t seem much point. Far Eastern manufacturers love kevlar, but we’ve yet to see any real puncture-resistance benefits, and in small sizes the rolling resistance can really suffer. If you buy a Mezzo – and we don’t want this to put you off – trade up to Primos, Schwalbe Stelvios, or even (dare we suggest it?) the yellow flash non-kevlar Brompton tyres. Any of these will The Cheng Shin tyres are a transform the bike. bit disappointing

The Mezzo will be available in two forms – the i4, fitted with Shimano’s long-in-the-tooth Nexus 4-speed hub, and the d9, complete with the delightfully compact Shimano Capreo derailleur. Following Shimano’s recent production problems, the Capreo-equipped bike is unlikely to be available before May, so we’ve only had a chance to try the 4-speed. Good and bad news here – it’s a solid, stodgy, reliable hub that can be pedalled through most changes without complaint, but it’s inefficient, and it has a narrow (184%) gear range. It also weighs nearly as much as a modern 8-speed hub.

With market research suggesting that folding bike users would demand low gears, the ATB engineers chose unusually low ratios – top coming out at a rather pedestrian 69 inches.This is, quite simply, too low (lower than the new Brompton 2-speed, for example). We’d suggest the i4 needs at least another gear to be competitive in the cut and thrust commuter world.The company intends to give the sportier d9 an even lower 64-inch top gear, suggesting it will run out of steam just as the Brompton rider in front shifts casually up to Gear 5, with one more to go.Yes, the i4 (and the d9 if they don’t fix the problem) will be up to wobbling around yacht marinas, passing Stridas and other low-aspiration folders, but in our opinion it deserves better.They really should think again.

Folding

Folding Pedal

Perhaps wisely, ATB claims only that the Mezzo ‘unfolds in no more time than it takes to tie your shoelaces’. Folding times tend to be as long as the proverbial bit of shoelace: we’ve seen both the Birdy and Brompton folded in less than ten seconds, but we’ve seen other people struggle to fold the same bikes in five minutes. No doubt the Mezzo will be much the same.

What matters more than outright speed is consistency and repeatability. Try folding any bike in a bitterly cold drizzle on a dark station platform and you’ll appreciate what this means. It’s an area where the Brompton tends to excel, and the good news is that the Mezzo is also reasonably easy.

As with most folding bikes, it’s important to fold and unfold in the correct order or you will get in a tangle and possibly do a whoopsy to your accoutrements. In this case, you start by positioning the right-hand pedal towards the rear and rotating the handlebars fully anti-clockwise. It’s now possible to lift a safety catch (unlike the rear-suspended Brompton, the frame locks in place) and rotate the rear wheel under the bike, which now stands on the rack.This ‘lazy fold’ in ATB parlance, sits rather like a parked Brompton, and it’s small enough to put aboard the roomier sort of train. Incidentally, if you have a beautiful teak-effect parquet floor, don’t stand the folded Mezzo on it.The front mudguard  sits on a football stud, and the rear reflector stays protrude far enough to leave some nasty gouges.

Front-wheel quick release and safety catch

…by slowing the bar,  the second catch is arguably counter-productive…

To go smaller, release the front axle quick- release, flick off a safety catch and fold the front wheel and mudguard assembly back until the mudguard stay engages with a catch on the rear frame.The seat post can now be released and slid fully down, where it should engage with a lower stop bolt, holding the package together, rather like the Brompton or Birdy. Finally, there’s a fiddly safety catch to undo before the Mezzo’s trademark over-centre stem catch can be flicked up, allowing the handlebars to drop down against the front wheel.

Fully loaded. The front wheel has swung round and back to clip against the frame. The handlebars are hanging free, but the seat pillar has engaged with a stop to prevent the rear wheel unfolding

The handlebar hinge partly engaged. The spring-loaded bar is lifting up and over the curved plate. As the hinge closes, the bar snaps into place underneath the plate, securing the joint.

Fully closed, the bar is now out of sight and the two curved faces have mated, producing a tidy joint. Note the safety catch below.

The catch is interesting, and presumably The forms one of the key patents on the handlebar hinge partly bike. Actually, there are two of them, engaged.The spring-loaded bar is lifting up and over the curved plate. because the catch holding the rear As the hinge closes, the bar snaps frame is similar, but the handlebar into place underneath the plate, stem is the safety critical one.The securing the joint hinge itself is crude and quite loose on our sample, but it plays a relatively minor role once the catch is in place. The real strength comes from the engagement of curved mating faces on the upper and lower seat pillar, Bar which are pulled tightly into engagement by the catch.This Fully closed, the bar is now consists of a out of sight and the two metal bar curved faces have mated, that lodges producing a tidy joint. Note the safety catch below Hinge Plate beneath a cleverly-shaped alloy plate. As the spring-loaded bar pushes under the plate, the hinge locks firmly together, but it can be released in an instant by pushing the bar back the way it came.The fiddly secondary catch was insisted upon by nervous lawyers, and serves little purpose. In fact, by slowing the advance of the bar – which tends to work best when snapped smartly into place – the second catch is arguably counter- productive.The word on the streets is that regular commuters may wish to remove it, but you didn’t hear that from us, or from ATB for that matter. Fully folded.The front wheel has swung round and back to clip against the frame.The handlebars are hanging free, but the seat pillar has engaged with a stop to prevent the rear wheel unfolding

We’re always wary of new catch designs.This one is clever, but it relies on fine engineering tolerances.The bar can be adjusted to take account of wear, but this is something that would have to be done with care. In use, it’s best to be assertive, because a half-hearted fold can result in the catch failing to go all the way home, leaving some play in the joint.We expected it to work best oil-free, but the excellent manual suggests greasing the catch and oiling the hinge once a month, so we’ll accept their judgement. Even allowing for poor maintenance, we don’t think the joint could separate in use. However, there must be a question mark over the long-term survival of the hinge assembly, which started loose on our bike and is unlikely to improve.

Something of an omission, but easily rectified, is the lack of a clamp to hold the folded handlebars in place. Long experience has taught us that loose bars will sooner or later trip you up as you run for the 17.44.The Mezzo comes with a pair of (unbranded) folding pedals, but only the left one is really useful. Push the pedal body inwards and it pivots down, leaving a bearing block protruding about 5cm.

Those familiar with folding bikes may be wondering where the chain has gone. A short tensioner arm keeps the chain taut in normal use, but when the bike begins to fold it soon reaches its limit. At this stage, two pegs take over, lifting the chain and wrapping it round the chainring.The process is even crueller than it sounds, because like the Bike Friday, the rear frame pivot is offset, so as the frame rotates down and forward, the wheel ends up some degrees out of line with the chainring, distorting the chain sideways.Things may be more complicated with the derailleur, but on our variant this clever mechanism works well, peeling the chain off and returning it without any  oily calamities. Unfortunately, the same isn’t true on the road: jumping over a small curb, our chain popped off the chainring and got tangled up with the pegs, resulting in lots of swearing.

…folding the hub-gear version is easier and cleaner than the Birdy…

Niggles apart, the Mezzo really is quite easy to fold, and it also produces a reasonably small package.The derailleur may be more demanding, but the hub-gear version is definitely easier and cleaner to fold than the Birdy, if rather more involved than the Brompton, which really can be done with your eyes shut with practice.

Unfolding is arguably easier, thanks to the clever over-centre catches.These thump into place, producing a rigid joint with a satisfying click.You only really need to get your brain in gear when reassembling the front wheel. Obviously, the wheel has to go all the way back where it came from, allowing the catch to fall into place, and you must remember to follow this up by tightening the conventional quick-release.

Folded size is good, without breaking any records. As delivered (personal saddle and handlebar adjustment will make a difference), the folded Mezzo is 33cm wide, 64cm tall, and 75cm long.That’s a folded volume of 158 litres or 5.6cu ft, which is smaller than the Birdy, and marginally smaller than comparable 16-inch bikes, such as the Pashley Micro, Dahon Presto or Tactic Panache. As usual, the Brompton is in a class of its own, occupying around half the volume of the other compacts, but the Mezzo runs an acceptable second place. It’s a neat and practical folding bike.

Weight seems disappointing, but as with the Brompton, that’s an illusion brought about by the small folded size. In fact, at 12.2kg (26.8lb), the Mezzo i4 is a shade lighter than the equivalent Brompton M6 (but without dynamo lights, of course). A lighter hub, pedals and tyres could bring the weight down to 11.6kg (25.5lb), so there’s plenty of room for future developments.

Accessories, Adjustment & Servicing

Initially, the Mezzo comes with very little in the way of accessories, but we’re pleased to see a proper pair of mudguards.The front one is structural, so it’s an indestructible alloy affair. Otherwise, there’s just a bell and a slightly naff-looking saddle-mounted LED rear light. If ATB is serious about the folding world, the Mezzo needs proper lights, and some sort of luggage system. It has a rear rack, but in the morning commuter maelstrom, the man fiddling with panniers and bungees is the man who misses the train.The bike needs a custom rack-mounted bag and quick-release system, and we’re told there’s one on the way. Proper frame-mounted LED lights are being developed too.

Excellent news for taller people is that the saddle goes up to 107cm, which is way taller than the opposition. Unfortunately, the bars are adjustable over a rather limited height range of 105 down to 102cm, which is too tall for shorter folk. And, at a shade under 100cm, the wheelbase is a bit short, putting the micro-adjust saddle too close to the bars for taller people. Actually, nearly everyone found a comfortable position on the Mezzo, but not all.The help of the sort of dealer willing to discuss inside leg measurements and crotch comfort zones is essential here.

Brakes are Promax dual pivot calipers. As with many folding bikes, the short wheelbase effectively dictates the front wheel braking force, while a convoluted cable run limits power to the rear.When new, a mighty heave on the rear lever gave a barely adequate stopping force of around 0.33G without quite locking the wheel. After a few miles, this improved slightly, to the point where the wheel could just be locked up. At the front, the Promax caliper easily achieves 0.61G, but at this point the rear wheel is beginning to lift. In general, braking performance is similar to the Birdy, but the longer wheelbase on the latest Brompton helps to keep the rear wheel on the ground for a little longer.

Conclusion

The Mezzo is a very interesting design.The faults might sound serious, but they’re mostly in the detail, so upgrading should be easy.We’d like to see some work done on the tyres, with the option of something like the Stelvio, or a Primo derivative as soon as practicable, enabling the bike to pull higher gears.To be really competitive, it needs a top gear of 80 inches, or even more if the rolling resistance can be sorted.

As for the gear system, the Mezzo has a full 132mm frame drop-out width, so ATB can fit any hub it wants.The Sturmey or Nexus 8-speed would be ideal, giving a much bigger gear range than the Brompton, and matching the more expensive Birdy derivatives.

Would we buy it now? We’d certainly get down to the nearest dealer for a test ride. The Mezzo is the first really serious challenger to the Brompton. It doesn’t fold quite as small, but it looks techier, and with the right running gear it could outpace it. Interestingly, although most Brompton owners rejected our sample for a variety of reasons, those who had decided against the Brompton were delighted. Key observations were plenty of saddle height and a rear wheel that didn’t fold under when lifting the bike. Price will have an influence too – at £595, the Mezzo represents quite good value for money.

Specification – Mezzo i4

Mezzo i4 £595 . Weight 12.2kg (27lb) . Gears 4-spd Nexus Hub . Ratios 37″, 47″, 56″, 69″ Folded Size W33cm H64cm L75cm . Folded Volume 158 litres (5.6 cu ft) . Manufacturer ATB Sales web www.mezzobikes.com mail info@atb-sales.co.uk tel 01424 753566

A to B 47 – Apr 2005