by admin 0 commentsJuly 20th, 1988
A recumbent trike that folds
GT3 FOLDING TRIKE
Recumbent bikes and trikes are cumbersome things, which helps to explain why they remain relatively unpopular for day-to-day use, although for recreation and sheer entertainment, laid-back cycling is unbeatable. There are a handful of practical folding recumbent bicycles around, notably Bike Friday¹s ever-so-clever 16-inch Sat-R-Day, but trikes are trickier to transport. For car-top recreational use, that¹s hardly an issue, but we don¹t go there, so you¹ll have to read about such things elsewhere. For preference we try to choose machines that can be carried by train or plane, or tucked in a bike trailer, that sort of thing. The only recumbent trike that passed the A to B criteria was Nick Abercrombie Andrew¹s GNAT folder (see A to B 8), albeit at the expense of considerable cost and complexity. GreenSpeed is an Australian manufacturer, and one of those companies you think you know all about, but discover you knew very little. It all began back in 1990, when Ian Sims, an ICI laboratory technician, lost his job. Ian had been involved in the motor racing world, designing and building his own mid-engined sportscar and a number of electric racing machines, but with time on his hands, he began to investigate more relaxed transport, and his mind strayed towards the alternatives. This process was given a vital extra impetus when Ian lost his licence (94 clicks in a 60 zone!). After dissecting and dismissing his sons’ mountain bikes, the race-orientated mind began to think along more wind-cheating lines. The final piece in the jigsaw followed a ride on an early Trice recumbent trike, which brought Ian to the time-honoured conclusion that he could do better. Later in the year, with a prototype under his arm, Ian entered the 540km Great Victoria Bike Ride, and – although rider and machine were largely untested – he found himself completing the 80km daily stages by lunch-time and waiting for the more conventional ‘safety’ bicycles to arrive. The first production machine was sold to a New Zealander who had been on that original ride, and the business slowly grew. Within five years GreenSpeed had moved from a family workshop to a factory unit ‘five minutes down the cyclepath’. In another five years, the company had absorbed the two adjacent factory units and was churning out 250 trikes a year. Of the 1,400 built to date, more than 80% have been exported (mainly to the United States) generating foreign exchange of $1.6 million AUD, of which the company is justifiably proud. Ian is much too polite, so on his behalf, we¹ll blow a long overdue raspberry at ICI.
For some years, GreenSpeed has concentrated on smallish 406mm (20-inch) wheeled machines, but there has been a gradual move towards the ‘Brompton’ 349mm (16-inch) format, and the GT3 is the latest of these. The big advance is the incorporation of a hinge in the mainframe, and construction in Taiwan, resulting in a budget price (in recumbent trike terms) of about £1,900. Small wheels are useful on bicycles, but overwhelmingly beneficial on recumbent trikes: the wheels are stronger and lighter, offering faster acceleration and reduced wind resistance. They also exert a lower twisting force on the frame when cornering, so the frame can be made simpler and lighter, and they reduce the length and the height of the machine, cutting wind resistance still further. And with the rider sitting closer to the ground, a slightly more upright seat can be fitted, improving comfort and visibility. Rolling resistance is a little higher with 349mm tyres, but the GT3 comes with Primos – still arguably the free-est rolling and lightest 349mm tyres on the market. In any event, the higher rolling resistance is almost certainly outweighed by the benefits. True, the small wheels can ride a bit harshly on poor roads, but as we shall see, this can be improved. Recumbents are produced with a variety of seat angles, from laid back versions of a conventional bike to a near full recline, which gives the least wind resistance but puts a nasty crick in your neck. In recumbent terms, the GT3 has a relatively conservative 40 degree seat back – a reasonable compromise between visibility and a low frontal area.
Once the boom length has been set and you¹ve levered your feet into the toe-strapped pedals, you¹re away. Like all the best trikes, the GT3 has lots and lots of gears, fingertip control, and a transmission that translates every ounce of effort into forward motion. If you haven¹t ridden a well-sorted recumbent trike, you¹ve missed out on one of life’s Great Experiences. And by any standards, this well-balanced and agile, yet forgiving, machine is an experience you’re unlikely to forget in a hurry. Like all the best mid-engined sports cars, geometry and weight distribution have been chosen to give handling that’s broadly neutral – in other words, should you over-cook things on a sharp bend, the GT3 will neither plough straight on, or head for the apex. We rode the trike in all sorts of conditions, with a variety of tyre pressures and several drivers, and the thing cornered throughout as though on rails. This seems to hold true on dry surfaces, wet surfaces and – a Somerset speciality – manure-covered surfaces. You need to concentrate, because things happen very quickly when you’re sitting on the ground, but we’d guess that’s part of the fun with a mid-engined sports car too. With a bit of familiarity, you soon find yourself cruising through corners that would send a cyclist sliding into the hedge. Once in a while, the front Primo tyres scrabble for grip, and occasionally the rear end ducks and dives on a bump, but at bicycle speeds, there’s plenty in reserve. Unlike an upright bicycle, it isn’t really possible to absorb bumps using your legs and body. Initially, we inflated the Primo tyres to their maximum pressure of 85psi, which worked well enough at the front, but the jarring and vibration from the back wheel was enough to give blurred vision on indifferent surfaces (they¹re the only kind in these parts). After a bit of fiddling, we settled on 40psi at the rear, which improved the comfort level immensely, and had no obvious effect on performance. The front tyres seemed less critical, presumably because vibration from the front passes through a squidgy bottom rather than a relatively bony upper back. In all the excitement (yes, every ride is exciting), you tend not to notice that you’ve become plastered in the water, mud and bovine waste material that made it all so entertaining. The GT3 has a substantial rear mudguard and mudflap, but there’s no protection at the front. Normally, spray from the front wheels shoots clear in two muddy arcs, but occasional changes of direction or errant wind eddies send a chocolatey spray across your arms, chest and face. There’s not much you can do about this, except emigrate somewhere drier or reckon on taking a hot shower after every ride. Progress on the GT3 is exceedingly rapid, and even when it isn’t, it appears to be, which is what getting from A to B is all about. Our test hill revealed an average speed of 15.4mph – much faster than a 16-inch wheeled bicycle, indeed broadly similar to a full-size racing bike. On steep descents, speed rises rapidly, and when you’re this close to the ground, 20mph seems fast, and 30mph becomes sound-barrier stuff.
Steering a 68cm-high projectile down country lanes is all very well, but sooner or later you’ll need to apply the brakes. The GT3 has no rear brake, so the legal requirement for two independent systems is taken care of with separate Sturmey Archer front drums and levers. This not only gets around the brake balance problem (see KMX trike, A to B 37), but enables the rider to make hand gestures whilst braking in a smooth and controlled manner with the other hand. The magic ingredient is some carefully chosen geometry, including ‘centre-point’ steering that puts the tyre/road contact patch immediately under an inclined steering pivot. Should you apply one of the two front brakes, there’s very little tendency for the bike to swivel around the contact patch, so it stops in a straight line. On the GT3 you can make quite harsh stops with one brake and feel barely a twitch in the steering. A panic stop locks the wheel at 0.3G, but the trike still pulls up more or less straight (or in a curve, if you happen to be cornering). Peak performance, using both brakes, is around 0.6G, and those with strong hands can hit 0.65G, at which point the rear wheel begins to lift off. Either way, the stop is nicely controlled and drama-free. To get the best from the brakes, you have to juggle the levers for perfect balance, but the GT3 provides plenty of feedback, particularly at higher speed. Within a few miles, your body learns to react to the subtle messages from the wheels, but even if you get it wrong, the trike is essentially fail-safe.
Hill climbing is a bit disappointing, not because the GT3 climbs particularly slowly, but because the climbs are markedly slower than the descents. Actually, the trike maintains a good pace on the sort of mild nagging gradients that might depress a bicyclist, but on steeper climbs, the bicycle is quicker, leaving the trike rider to sit it out and think about the fun they’ll have going down the other side. Thanks to their relatively poor hill-climbing and slick descents, recumbent trikes usually come with enormous gear ranges, with GreenSpeed typically providing three separate stages, and as many as 72 gears. On the 16-inch wheeled GT3, there just isn’t the space, so the machine is fitted with the new Shimano Capreo derailleur, specifically designed for small-wheelers. This nine-speed gear cluster, coupled to Shimano Tiagra triple chainrings, gives a near 500% range, and 27 gears in three groups: 20″- 57″, 27″- 79″ and 34″- 98″. Not quite low enough for serious climbs, or high enough for spinning down long fast descents, but a fair compromise. The Capreo gear cluster is unusual – the six largest sprockets slide onto a conventional freewheel hub, with the 11, 10 and 9-tooth tiddlers individually mounted on a smaller splined shaft. This will no doubt prove useful, because you can bet the small ones will wear out fairly quickly and cost a fortune to replace. With such tiny sprockets, the chain tends to oscillate in speed as each tooth passes, which can be felt as a soft (but by no means annoying) vibration in the highest gears. It’s hard to judge how efficient the Capreo is, but it provides a good range of gears, and helps to keep the chainrings down to a manageable size, even on a 16-inch bike.
A to B Things
The GT3 makes an excellent platform for the school run – a bit unconventional, but you’ll get home before the other parents have walked their children to the car. Generally, a child seat is mounted above a 26″ wheel, putting the child behind and slightly below the rider. On the GT3, the seat mounts atop a smaller 16-inch wheel (albeit on a 20-inch rack, so not quite as low as it might be), but you’re sitting lower still, giving the child a grandstand view over your head. Perching 20kg above the rear wheel is a bit like strapping a rhinoceros to the back of a sport car. On corners, the GT3 betrays a definite nervousness as the child seat gently twists the rack and frame, but it still runs true as a die, at the usual rocket-like speeds in a straight line. Panniers, of course, are mounted much lower, so this pendulum effect should be minimised. Any of the shorter jobbies suitable for 20-inch bikes will fit, and there’s plenty of clearance. The rack has a bracket for a standard LED rear light, and the frame features braze-ons for a dynamo (not a great idea with frail Primo tyre sidewalls), a front light and a bottle cage. There’s also a mirror, mounted on the kingpin in classic trike style, but the stem is really too short to provide much information. Obviously, light touring is well within the GT3’s capabilities, but with ground clearance of only 7cm, you’d be well advised to stick to the black top. On a more practical note, the turning circle of 3.3 metres (10′ 9″) is one of the best around, making U-turns and other dubious manoeuvres dead easy. This may not look like a shopping or nip-to-work machine, but provided you’re willing to mingle with traffic at wheel-nut height and you keep clear of road humps, all the practical elements are there.
Almost forgot. Folding involves removing the single seat bolt with a 6mm allen key, which exposes the hinge in the main frame tube, or ‘spine’ in recumbent-terminology. The hinge is a nice bit of engineering, superficially similar to the Zero hinge (see page 35), but neater and lighter, with an even craftier safety catch. Like the Zero, the quick-release pivot shaft forms the catch, engaging through a hole on the front hinge face. But in this case, a peg on the shaft engages with a cam cut in the hinge body, so the catch will only disengage when the quick-release is rotated down and back. Like the Bike Friday, the hinge is asymmetrical, so the rear frame swings up and to the left, allowing the rear wheel and rack (if fitted) to nestle snugly between the left front wheel and the boom. The lengthy chain pivots at around the same point, so it stays in tension. With the seat strapped to the right of the fully retracted boom (another 6mm allen key job), the trike measures 82cm wide x 52cm tall x 101cm long. In bicycle terms, a folded volume of 430 litres (15 cubic feet) would be vast, but for a trike it’s really quite compact. And the folding process takes only a minute or two. This sort of performance brings the GT3 into train territory, provided you keep a low profile and are very nice to the guard if spotted (technically, trikes are not allowed on trains). We’d strongly recommend putting it in a bag, both for protection and disguise. A typical hatchback car would be easy, although squeezing the GT3 into a car boot might require a little more work. If you’re prepared to get into the oily dismantling zone, there are plenty of other options to make the machine quite a bit smaller. Remove the wheels (a single allen screw for each front wheel), steering assembly (one bolt, again), derailleur and chain (more fiddly) and boom, and in about 30 minutes, the bits can be squeezed into a case measuring 38cm x 71cm x 77cm. We can vouch for that, because that’s how our trike arrived, hot from its launch at the Interbike trade show in Las Vegas. Yes, it’s big by train or plane standards, but a transport trike nonetheless.
With most of these machines being unashamedly roof-of-the-car jobs, the GT3 has very little competition. A bit disappointing that the ultimate HPV has to be carried everywhere by car, but there you are. Green transport, eh? The traditional trike manufacturers seem to have become a bit set in their ways, selling increasingly expensive machines to wealthy and slightly paunchy middle-aged men with beards. For what it’s worth, a typical Windcheetah, Trice or GreenSpeed (pricing is difficult because recumbents are virtually bespoke) costs £2,400 to £3,000. That’s a great deal of dosh for most of us. Against this background, the ‘entry level’ GT3 is a nice, simple practical package, selling for £1,900 or so. No super-duper components, but enough performance to satisfy all the hot-blooded young things who tried it, and leave some of them making lost puppy noises. Quite how many of these un-bearded types with a mortgage and two kids would be allowed to part with two grand is another matter, but there’s no doubt that the GT3 represents a breakthrough pricewise. It’s also a lovely-jubbly machine – do try one.
GreenSpeed GT3 £1,900 . Weight 18.2kg (40lb) . Gears Shimano Capreo/Tiagra derailleur Gear ratios Low 20″-57″ Medium 27″-79″ High 34″-98″ . Brakes Twin Sturmey Archer drums Brake force (one wheel) 0.3G (both wheels) 0.65G . Tyres Primo Comet 37x349mm . Track 74.5cm Overall width 82cm . Folded size H52cm W82cm L101cm . Folded volume 430lt (15 cu ft) Manufacturer GreenSpeed web www.GreenSpeed-trikes.com mail ian@GreenSpeed-trikes.com tel +61 9758 5541 . UK Distributor Westcountry Recumbents web www.wrhpv.com mail firstname.lastname@example.org tel 0870 7401227
Australian CYCLIST – This road test was published in the June – July issue, 1998. Australian Cyclist is published by the Bicycle Federation of Australia, www.bfa.asn.au