reliable chain drive system

[robin cook]

hi. i am new to this forum and located in the uk.
i am building a quadracycle which i intend to motorise. uk law stipulates 250 watts max for motor assist.
obviously chain drive is more efficient than hub systems.

searching the web i have located the lohmeyer system, but which is hopelessly expensive. then there is the cyclone, but the web sites promoting this system are somewhat confusing and i get the impression that this system is still under development (?). finally some sites sell very cheap chinese scooter motors and controllers - would these be suitable?

in sum, can anyone direct me to a simple, not-too-expensive, and above all reliable system? or is it the fact that the as of 2009 the market is as yet fluid and immature?
i would hope that there is a simple solution to the problem - here in the uk the situation is rather dire. governments pretend they support cycling but in practice roads are very dangerous and the country lags greatly behind the rest of europe (actually echoed in many other sectors like child poverty). so nothing too hot shot, but a simple reliable system that may help us reclaim the roads from car frenzy. any suggestions gratefully received.

yours faithfully, robin cook

 

[spinningmagnets]

Low-power systems desperately need gears. I have seen internally-geared hubs (such as the Sturmey-Archer 3-speed, Nexus, etc) used as an intermediate jackshaft. I have also seen the common external gears and derailleur used. For a quadricycle, I would recommend having separate pedal-drive, and motor drive.

The labeled power output of a motor is only at its rated volts and amps. Increasing amps will increase the heat in the motor, and will also help acceleration. increasing volts fed to the motor will increase motor-RPM's (top speed). 750 watts is roughly one-horse-power. The watts are volts times amps.

You can achieve 250W (1/3-HP) by using 48V at 5A, 36V at 8A, 24V at 10A, or 12V at 20A. Higher voltage is desirable. If the motor is rated at 250W at 24V it would be very common to feed it 36V. Your sprocket choices can decide what your top-speed is at any voltage.

By raising the volts and then occasionally raising the max amps a little, you can get 500W of power from a motor that is labeled as a 250W, but be cautious about motor heat. If you ride safely, nobody will care about the actual power of the bike.

 

[deardancer3]

The stoke monkey is reliable but bulky and dont know if it is available for 250w.

I have very good reliability out of my chain drives. the giant Lafree Lite and the Cyclone 360w system.

the cyclone with the double clutch on the motor shaft is nice, but the motor still need to be waterproofed where the harness enters, and you need an aftermarket throttle. I have no problems with my 360w cyclone.

d

 

[gwhy!]

Hi Robin,
Welcome to ES, If it of any use to you I have a smallish brushed motor and speed controller and a few other bits and pieces that I no longer have a use for, I am also in the UK so postage should not be to bad if you are interested please drop me a PM and I will give you all the details. Im not around for a few days so if you do PM me I will not be able to respond until Monday.

Cheers.

 

[Sturdly]

This might give you a few ideas and inspiration...... http://www.oaktreevet.co.uk/Trike/trike.htm