Shaft drives look great on paper, trading that grubby old chain for a completely sealed unit – no gear teeth, no oil, no grime, and no hassle. In reality, they’re relatively inefficient, noisy, heavy and expensive. Altering the gear ratio is a major engineering job, and even measuring the ratio can be complex. Forget what the salesmen say.The chain remains with us today – essentially unchanged for over 100 years – because it’s a damn good solution, unmatched by older and more recent inventions, such as the toothed rubber belt, shaft, oscillating rods, hydraulic, electric and all the rest.

Having demolished the genre, we couldn’t resist a review of Zero’s shaft-drive folding bike, partly because we think a folder brings a novel set of problems to which a shaft- drive is particularly well suited, but also because it’s a really pleasant little machine.

For £475 (about the same as the Giant Halfway) you get a simple, rugged 20-inch wheel fold-in-half bike, with V-brakes and Shimano Nexus 3-speed hub. Is it a better buy than a conventional 20-inch folder?

How it Works

Zero, the Bristol-based importer of shaft-driven bicycles, make no bones about the origins of the folding derivative.Taiwanese manufacturer Sussex sent over a rather heavy steel folder, but there was some interest, so a deal was done for supply of a lighter alloy-framed version, and this is it.

The business end is simple in terms of components, but no doubt fairly complex to manufacture.Where the bottom bracket bearings would normally be, there’s a large shell containing two substantial ball bearings and a shaft with a bevel drive cog splined loosely to it.We’re not over-keen on this design, because bevel gears exert forces in all sorts of directions. Only time will tell whether the splines are sufficiently robust – if they wear out, the unit will probably have to be scrapped. From the bevel gear, drive is transferred through 90 degrees, along a shaft to the rear wheel, where another pair of bevel gears transfer the pedal effort to a conventional geared hub.

Right-angle gears need to be precisely machined and installed if they’re to operate smoothly and quietly.This system can be a little noisy, because alignment between the bits and pieces is not all it might be (we’ll come to that), but the efficiency feels good – certainly streets ahead of a toothed rubber belt, for example. Zero claims efficiency similar to a chain drive, but we’ll stick with Bicycle Science, which quotes figures of ‘up to 98.5%’ for a chain drive and 92% for a shaft drive, admittedly an early 20th Century example, when such things were last in vogue. From a seat-of-the-pants observation we’d say that figure was probably a bit pessimistic, but losses there certainly are, compounded by the somewhat inefficient Nexus hub.

The bearings and cogs are pre-greased, but they’re not packed with grease and the assembly is not sealed, so if you were to ride through deep salt water for example, the system would need a thorough service.There’s a grease-point at the front, but this only lubricates the front bevel gears, not the bearings. At the rear, the assembly is effectively open to the elements, because of the way the rear wheel pops out.You whip off a plastic cover plate and slide the wheel back complete with its bevel gear. Grubby water can, and will, find its way in here, so the rear cogs are quite exposed. Not as exposed as a typical chain, of course, but by no means safe from the elements.

The Zero arrived with junior 150mm cranks – a strict no-no unless you’re a junior, or an adult with particularly bijou inside leg measurements.This felt most peculiar, but when swapped for more conventional 170mm cranks, the folder felt relatively normal. Not quite normal, because the gears produce a low hum, which can be felt as a slight roughness through the pedals. Incidentally, if you do go for 170mm cranks, the bottom bracket is a bit low, so the pedals are liable to hit the ground on sharp turns.

Gearing is effectively fixed, and although the ratios are on the low side, they’re an acceptable compromise at 30″, 40″ and 55″. First gear will climb reasonable inclines and top will just see you up to a passable cruising speed. For riding short distances in an uppy- downy sort of town you might be all right, but 55 inches is too low for spinning along on the flat with a following breeze.Take it or leave it – the ratios are not for changing.

On the road, the bike feels stable and quite sprightly. It’s easy to ride hands off, and the frame is surprisingly rigid, even when riding out of the saddle. Sussex recommend greasing the drive-shaft at 500km and every 4-6 months thereafter.We mention this because our bike developed some strange squeaking noises within a mile or two. Grease at the rear made no difference (simply remove the plastic cover and spoon it in), but a few strokes with a grease gun at the front solved the problem.What we can’t tell you is how the shaft will survive in the longer term. In theory it will last for decades, but if muddy water gets in, it could grind itself to bits in a few weeks.

…wheel location is rather vague… the drive could do itself a whoopsie…

Equipment

Every thing is unbranded, but by no means the worse for that.The V-brakes have smart alloy levers and work well enough, although the rear brake is hampered by a long and rather convoluted cable run. Both the gear and brake cables are forced into some excruciating positions when folded, so we wouldn’t expect them to last very long.Tyres are Kenda Kontacts – yet another 47-406mm (20-inch) design from this prolific Taiwanese manufacturer.The descent speed of 13.6mph on our test hill is the sort of figure we expect to see from good 16-inch tyres these days, so a relatively poor performance for a 20-inch bike. Mudguards are silvery plastic and unusually generous for a machine of this kind, offering reasonable weather protection, although the front could do with a mudflap.

Should you be worried, the rear wheel is easy to remove. First, the plastic cap comes off the shaft housing, then the mudguard stays, because a horizontal drop-out means the wheel has to be removed from behind.With the gear shifter removed and the wheel bolts loosened, the wheel is free. It’s different, but no more difficult than normal.

Reassembly is a bit more critical. Engineering types may be wondering how the wheel bevel gear is accurately relocated in relation to the shaft bevel – it isn’t, or at least, not with precision one might expect. A the flanged hub nut fits into a recess in the  frame, and that’s it. On the other side of the wheel, location is rather vague, and assembly is not helped by the propstand, which mounts on a splined washer that also locates the hub and acts as an anti-rotation washer. It’s much too fiddly, and if you fail to fit these bits together correctly, the drive could slip, run roughly, or do itself a whoopsie. To be fair, derailleurs require some meticulous fiddling too, but that’s no excuse.

Both the saddle stem and handlebar stem are adjustable – the saddle from 75-96cm from the ground, and the bars from 101-110cm.That saddle height is broadly similar to the Micro or Brompton, but the bars are unusually tall, giving what some people would regard as a rather upright stance. Fine tuning of the saddle is easy, thanks to a nice micro- adjust seat post.

Folding

Sussex markets the steel-framed shaft-drive folder quite widely (you can buy it in the US for $385), but the alloy-framed bike is a more substantial, attractive, and unusually cleanly styled machine.The frame is finished (rather unnecessarily one might think) in lustrous silver metallic paint.The main hinge is a monstrous alloy block in classic Far Eastern style, but it works well enough and incorporates a clever safety device.The pin carrying the quick-release runs in the rear part of the hinge, and when engaged, it drops into a hole in the front part, locking the hinge shut. Even when the quick-release is unfastened, the hinge will not open until the pin is lifted. Simple and effective.The lighter handlebar stem hinge has a similar fitting.

Bikes like this tend to be tricky to fold, but the Zero does the job easily, quickly and without oily fingers.This is where a shaft drive really pays dividends, because you can grab the bike anywhere you please without getting a sticky surprise, and once folded, there’s no oily chainring to snag passers-by or make a hole in the carpet.

With both hinges released, the frame folds back on itself and you can choose whether to keep the front wheel pointing forward, Brompton style (in this case placing the handlebars between the wheels), or not, Dahon style, which puts the bars on the outside, leaving the cables rather vulnerable. Folded size Dahon style is 41.9cm wide by 61cm tall and 75cm long, giving a neat folded package of 191.5 litres or 6.8 cubic feet: almost identical to the similar Dahon Vitesse. Folded Brompton style, the package is both longer and taller, with a volume of 233 litres, or 8.3 cubic feet. Like most bicycles of this type, the Zero has no mechanism to keep the folded bike together, but Zero supply some nice velcro straps.

The folding pedals (the bike only actually needs one) are similar to the old VP – you pull out a locking plate and the pedal drops down leaving a rather large bearing housing. Branded Sunshine, they’re new to us, and not very clever. We’d advise Sussex to buy a few Next pedals, because they’re just that bit better in every respect.

The Zero folder weighs 13.8kg (30.4lb).That compares quite well with cheap and nasty 20-inch machines, but it’s about a kilogram heavier than the elegant Vitesse, which is exactly the penalty Sussex and Zero claim you’ll be paying.

Conclusion

For all its faults – primarily the 150mm cranks and 55″ top gear – we like the Zero folder and think it could make the basis of a low-maintenance canal path commuter, but only for smaller people. Make sure to ask for longer cranks, and to avoid fiddling with that rear wheel, we’d certainly want to fit puncture-resistant tyres (such as the Schwalbe Marathon Plus, just released in 20-inch form).That leaves only the brakes to go wrong, which they’re bound to do, now we’ve said that.

Price-wise, the Zero is in a weak position in a highly competitive market.You could buy two acceptable Dahons for £475, or spend the money on one well-equipped alternative, such as the Trek F400, or the stylish Giant Halfway. If you opt for 16-inch wheels, the Brompton L3 is lighter, a better folder, faster on the road, and cheaper.

Normally such comparisons would be the kiss of death for a newcomer, but the Zero has a certain indefinable something that keeps it in contention. It won’t become a design classic, but it’s different, and sometimes that’s enough.

Specification

Zero Folder £475
Weight 13.8kg (30.4lb)
Folded dimensions W41.9cm H61cm L75cm
Folded volume 191.5 litres (6.8cu ft)
Gears Shimano 3-speed hub
Ratios 30″ 40″ 55″
Tyres Kenda Kontact 47-406mm
Manufacturer Sussex Enterprises web www.sussex.com.tw
UK distributor Zero Cycles tel 01454 316563 mail info@zerocycles.co.uk