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

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.

…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.

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