Greenspeed Anura Trike

The Greenspeed Anura is an ideal tricycle for older people and people with special needs. Delta style tricycles like the Anura offer easier entry and exit compared to Tadpole style tricycle. The Anura also offers a higher seat height making the rider more visible in traffic. The Anura is unique being that it has a differential so both rear wheels drive the tricycle forward but yet does not hinder it ability to turn. The differential also helps the bike go straight up a steep hill where other tricycle that do not have a differential have difficulty because the front wheel will skid to the one side. Another unique feature is that both rear axle disc brakes are controlled by one brake lever and the other brake lever controls the brake on the front wheel. The under the seat steering put your arms in a more natural position besides your hips.

ANURA HISTORY - Design and Development

There are now four versions of the Anura :-

• 1. The RL Anura has the standard “27 speed” derailleur gear system, comprising of a 9 speed rear cassette and derailleur, plus a triple crankset. This gives a gear range of 14 gears from 18 to 80 inches. This setup uses a mid-cage rear derailleur, giving 2” of ground clearance with the standard 16” wheels.
• 2. The SL Anura has the Schumpf Speed Drive instead of the triple crankset. This is a two speed bottom bracket which does away with the front derailleur and derailleur post, making the front of the trike a lot cleaner and easier to mount. There is less overlap of gears with 18 possible gear combinations giving a range from 21 to 87 inches with 13 individual gears. This system only needs a short cage rear derailleur, giving 3” of ground clearance with the standard wheels. Another advantage of this system is that the Schumpf can be changed while stationary, so that if you have had to stop suddenly without time to wind down the derailleur gears, you can just hit the Schumpf button, and it will drop the equivalent of 4 derailleur gears to enable an easy take off from rest.
3. The IGH Anura takes the internal gearing one step further. As well as discarding the front derailleur, we now discard the rear derailleur and use a much cleaner method of changing gear than pushing the chain from one sprocket to another. IGH means Internally Geared Hub, whereby the gears are inside the hub instead of being exposed to road muck on the outside of the wheel. Almost any IGH can be used in the Anura, from a 3 speed Sturmey Archer to the 14 speed Rolhoff hub with a 500% range. However our standard set-up uses the Nu-Vinci continuously variable hub, the N360, plus the Sclumpf Speed Drive. This hub is an incredibly quiet and smooth hub with NO steps or clunks in changing gear as there are no gears inside the hub! It is continuously variable between the ratios of 1:0.5 to 1:1.8 (360%) and with the Schlumpf, this range is increased to 594%, or from 14 to 86 inches. Like the Schumpf, the ratio can be changed while stationary as well as under power. The complete absence of a rear derailleur or tensioner means not only less maintenance, but a more than doubling of the standard ground clearance of the SL from 3” to 6.5” with the standard wheels.

4. The Anura Quad is a quadricycle rather than a tricycle. While the narrowness of the Anura is very handy for getting through tight places, some people wanted more stability. So how to make it more stable while still retaining the narrow width and the high seat? Answer – add a wheel! The problem with adding a wheel to a tadpole trike is that on uneven ground one of the rear wheels will leave the ground, so if there is only one wheel drive, or two wheel drive with a differential, you will suddenly have no traction!And if you use two clutches, turning will be compromised. However with the Anura, thanks to the superior weight distribution, both drive wheels stay firmly on the ground, if a front wheel lifts, the other wheel seamlessly takes over the steering duties of both front wheels. After all, at this point it is just becoming a trike again! The Quad is achieved by changing the trike front frame for a Quad front frame, so it can be retro fitted to an existing Anura trike, and one could even have a trike or quad just by changing the front ends. Standard gearing on Quad is the 9 speed 11-28 cassette. However this could be upgraded with an 11/34 cassette or a Schumpf Drive.