How much punishment can a multi-speed freewheel take?

midwestmayhem said:

This morning I woke up, poured a cup of coffee, and looked out into the patio to see my 5hp Robin bike. Then a question popped into my head. There's plenty of people out there with kit bikes powering the multi-speed freewheel. And a few like me who throw the power and torque of much larger engines at them, keeping our fingers crossed and the bearings greased.

So how much can a multi-speed handle? If and when they do fail, what is it that usually goes first? (sprockets, chain, freewheel itself, etc..)

Click to expand...

There's only one way to find out.....DO IT!!

I've used 5hp 460 and ported Tanaka 47R engines thru the shift kit and 8-speed cassettes. I've broken many chains and wore out one cassette. This was all my fault, thru trial and error. All parts were standard-duty, not heavy duty or pricey.

The key to it all is to ALWAYS pedal a few seconds before, during and after shifting gears. Pedal for a few seconds from a standing start. Roll into your throttle at all times. IF you skip 2 or 3 gears at a time, it'll be a smoother engine power transition.

JMO, baby your shifts and do your preventive maintenance. You shouldn't have many problems.

Just do it!

I would use a freewheel gear cluster instead of cassette. The parts that wear out in a free wheel gear cluster (bearings, pawls) are easily changed (with a freewheel tool). When using cassette gears, the bearings and pawls are in the hub, and not easily replaced.
Freewheel gear clusters are usually limited to 7 speeds.

Freehubs are threaded into the hub but not part of it and can be easily removed, serviced or replaced, uses a stout 10mm allen key. http://steveukmtb.files.wordpress.com/2008/03/13hub.jpg

In any case, freewheels or freehubs, are fairly light duty, they are designed for the limited coasting on a bicycle that is primarily powered by pedaling.

A lot of recumbent trikes use multi-speed freewheels and many of the electric motors they use have a lot of torque. Check out Endless-Sphere.com forum.

You can buy a 8 and 9 speed freewheels. They are 40mm and 40mm +/- .2mm wide, respectively.

Make sure you don't mix-up the terminology between multi-speed freewheels and cassettes. See: Traditional Thread-on Freewheels

Removal of multi-speed freewheel requires the same tools to remove a cassette. A 10mm allen key is required to remove a freewheel hub from a cassette system, but not a multi-speed freewheel.

If you are interested in taking apart a single speed freewheel or a multi-speed freewheel, check out: Bicycle FreeWheel Basics

There is a special grease fitting made to grease your multi-speed freewheel. You don't need to take it apart unless you like to - just because you can.

Chris
AKA: Bigblue