GREENSPEEDER

Greenspeed's bi-monthly newsletter
No. 3 February - March 2004


Greenspeed's new entry level GT3 Folding Trike

 

NEW GT3 FOLDING TRIKE

"The time has come", the Walrus said.  And indeed it has.  Time has come to tell you all about what we at Greenspeed have been working on for over a year - a brand new trike!  So this newsletter will give you all the stuff you need to know about Greenspeed's new GT3 Folding Trike and more ;-)   

                                                                 Ian Sims, February 2004

Contents:-

    1. What is the GT3? - Design Rational
    2. Wheel size & folding
    3. GT3 Steering & Brakes
    4. GT3 Equipment, Options & Prices
    5. GT3 Delivery
    6. GT3 Specifications & Road Tests 

Please click any picture for a larger image.

 

1. What is the GT3? - History & Design Rational

Since 1990 Greenspeed has been designing and building recumbent trikes for everyday use, be it commuting or touring the world, and these trikes have been hand built in small numbers, using the best quality components. Thus, compared to mass produced bikes, the cost has been fairly high.

Of course, compared to a machine with 1/3 of its wheels missing, less frame, and a small saddle instead of a proper seat, the recumbent trike is always going to cost more than an ordinary bike, of similar quality.

However as the advantages of the recumbent trike are appreciated by more and more people, we find that more and more occasional and recreational riders are wanting trikes as well, so how do we help these people?

During our market research we found that these people often put their bikes on their cars and drove to their favourite riding place. Furthermore, judging by the expression on their faces while riding, compared to trike riders, it seemed they were too uncomfortable to ride to the park or trail.

So as our mission on this small planet is to get more people cycling more often, we decided that if we could produce a trike that folded, so it would go into the trunk of a car, and if we made it in large enough numbers, so that the price could be lowered to within the range of people who run cars, then they might be comfortable enough riding their trike, to run their cars less, and make our planet a better place to live :-)

 

 

1991 GRT 20/26 Touring Trike

Jeff McLean touring in India

 

 


1995 GTR Touring Trike

 

 


2003 GTO Travel/Touring Trike

 

 

 

2. Wheel size and folding

How to make a trike compact enough to fit into a trunk? Well as you may know, we have been making the GTC and then the GTX trikes with 16" wheels all round. We discovered that these had both weight and performance advantages over the 20" wheels used on the GTR and GTO, as well as being stronger and more compact. Plus we found that they rode just as well, if not better than the 20" wheels. The 16" wheels also allowed the track to be narrower, as they encroached less on the rider's leg space, as the front wheels were turned on full lock. Thus these wheels were specified for the folding trike. 

So how does folding work? 1st, to make the seat easy to remove, it is fixed in place by only one cap screw through the front of the seat. Once this screw is loosened, the rear of the seat can be lifted off the seat stay pegs, and then once the screw is withdrawn, the seat lifts right off.

This exposes the hinge, which is set at an angle, so that as the frame folds, the rear wheel and rack comes over, and sits down beside the cranks, making a compact package. The hinge has a quick release lever, and a safely cam, so that even if it comes loose, the hinge will not disengage until the lever is lifted forward and up, towards the front of the trike. Note that in folding, the chain, cables and all adjustments stay in place, so there is no need re-adjust anything after unfolding.

To pack down even further, the handle bars can be folded, the front wheels removed, and rack and cranks removed.  However this should not be needed to fit the trunk of the average car.

Folded size with wheels and rack attached is 36 x 33 x 21 inches. Folding or unfolding takes less than one minute.

Boxed, shipping size with wheels, cranks and rack removed is 30 x 28 x 15 inches.

Another benefit of the small wheels and narrow track means that the GT3 can be ridden through doorways and gateways that one would have had to carry the GTO through. So the GT3 should be great for riding to work, where there are space restrictions. Maybe it could even be parked under a large desk?!

 


GT3 - 16" wheels with narrower track

 

 


GT3 - Seat Removed

 

 


GT3 Frame Folded

 

 


Complete Trike!

 3. GT3 Steering & Brakes

For this trike we have reverted to the original Greenspeed crossover steering. There are a number of reasons for this:-

1. It enables the trike to pack down further than with the steering on top of the main frame tube.

2. It gives a much smaller turning circle, taking advantage of the smaller wheels.

3. It gives a sportier feel on the road, more in keeping with the recreational (fun) nature of the trike.

To eliminate "brake steer" a number of steps have been taken:-

1. Reduction of track.

2. Shorter, stiffer, thicker gauge crossmember.

3. Use of 16" wheels.

4. Use of drum brakes only.

In the smaller wheels, the drum brakes are more efficient, and give less windup of the cross member. Here is a quote from the 1st GT3 Road Test done by the UK folding bike magazine, A to B :-

Brakes

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.

From A to B, Issue #39, page 15.   www.atob.org.uk 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

A to B # 39

4. Equipment, Options and Prices.

Last year Shimano released a new group set, the Capreo, especially for bikes with small wheels. The jewel in this group set is a nine speed cassette with 9t and 10t cogs which are smaller than the normal smallest cog of 11t on most cassettes. The use of this cassette has enabled us to provide a reasonable gear range without the need for geared hubs, or oversize chainrings, providing a lighter and more cost effective solution to the gearing. Contrary to expectations, these small cogs have performed faultlessly in over a year of harsh testing, thanks to the fact that the  chain/cog tooth loading is lower with 9 cog on 16" wheels, than it is with a 11t cog on 26" wheels. With the standard Shimano Tiagra 52/42/30 touring triple crankset, the GT3 has 27 gears with a range from 19 to 95 inches. 

This is similar to a mountain bike gear range and should be adequate for most recreational uses. Should a wider, lower or/and higher range be required, then the Rohloff or/and Schlumpf equipment can be fitted at extra cost, as all frames will have the Rohloff OEM dropouts -see picture. The SRAM DualDrive will not be available on the GT3.

Mirror, rear fender, and safety flag are standard equipment. The standard GS rack will not fit due to the folding facility, so only the special Cro Mo heavy duty racks will be available, until the standard racks are ready. Other GS options available for the GT3 are the new head rests, front fenders, 2nd mirror, and the dynamo lighting sets. Dynamo, head light, and tail light mounts are standard equipment on the GT3, and most GS trikes.

GT3 base price - $2,950 AUD
HD Rack               $150 AUD
Front fenders         $135 AUD
Head Rest             $120 AUD
2nd mirror               $30 AUD

No, this is NOT a mistake - the price really is $2,950 and not the $4,950 of the GTR or more for folding!

How? It is mainly just question of numbers. Up to now we have been building and assembling trikes one at time, and only producing hundreds per year. So now we have moved into partnership with a larger company we have been talking with for a number years, who make bikes in the thousands, and the trikes will be assembled on their production line to our design and specification. As we never out source work unless it is a better quality than our own, you can expect the same quality or better!

The other things we have done to reduce price is to only offer red or blue in the frame colours, use only 27 gears instead of 72, and to have the luggage rack optional.

 


 New Shimano Capreo Rear Hub and 9/26 Cassette

 

 


Dynamo Mounting & Rohloff Dropout

 

 


Heavy Duty Rack

 

 5. Delivery

Due to the delay in delivery of Shimano parts this year, delivery of the GT3 will be slower than we had hoped for. The 1st batch of 50 will be delivered in April, and the next, larger batch, will be ready some time after May, when the main Shimano order arrives, some months late.

We are now taking orders for the 1st 50, and expect to have deposits for all these trikes by the end of this month.

Many of our dealers are getting one of the 1st 50 trikes as a demo trike, so hopefully sometime in April, you will be able to test ride one at your local Greenspeed dealer.

 

6. Specifications and Road Tests

GT 3 16/16 FOLDING TRIKE

STANDARD SPECIFICATIONS

Wheelbase 39" (98 cm)
Track 29.5" (75 cm)
Width 32.7" (83 cm)
Length 69" (175 cm)
Height 27" (68 cm)
Wheels 16" alloy rims
Tyres 16" x 1 3/8"
Brakes Sturmey Archer Drums
Gears 27 speed
Cranks Shimano Tiagra 52/42/30
Rear Cluster Shimano Capreo 9,10,11,13,15,17,20,23,26.
Gear Range 19 to 95 inches
Frame Cro Mo 4130 tubing
Seat Angle 40 degrees
Seat Height 10" (25 cm)
Leg length adjust. Telescopic boom
Steering Centre point Ackermann with inclined handle bars
Turning circle 12 feet (3.7 metre)
Ground clearance 2.6" (7 cm)
Weight 17kg (38 lbs)
Standard fittings Rack, rear mudguard, mirror, safety flag
Base Price $2,950 AUD

Specifications subject to change without notice

So with the GT3 we take a direct step forward to compete with the cars, by using the assembly line. We hope that the people who have asked for lower priced GS trikes will support us in buying the GT3, as only by selling more trikes, can we afford to build quality trikes in larger numbers, and thus lower the price, so that more can afford to cycle instead of driving, to make our planet a better place.

The 1st Road Test was published in A to B in December, and  please look out for upcoming road tests in Recumbent & Tandem Rider, Velo Vision, Bent Rider On Line, and Recumbent Cyclist News. 

Unauthorized "testing" of one of our Road Test pre-production trikes on the BMX track at the Out Door Demo Day, at Interbike, resulted in some frame damage. See picture. Fortunately this was easy to repair, and Christine is now using this trike as her transport to and from the factory. As a result of this testing the production frames will be a little stronger ;-)

Ian Sims February 2004

 

 

 

 

 

 

 

 

 

 

 

Unauthorized "testing" on the Dirt Demo BMX track at Interbike,    Las Vegas, NV, USA

Picture - Mountain Bike Action, Feb. 2004

Greenspeed Recumbents
69 Mountain Gate Drive
Ferntree Gully
VIC 3156
AUSTRALIA
Phone +61 (0) 3 9758 5541
Email ian@greenspeed.com.au
Web Site www.greenspeed.com.au