View Single Post
Old 03-27-2012, 02:03 AM
BarelyAWake's Avatar
BarelyAWake BarelyAWake is offline
Motorized Bicycle Elite Member
Join Date: Jul 2009
Location: Maine
Posts: 7,212
Default Re: DIY tank... even if you can't weld

Defo lookin' forward to seein' the ol' Elgin on the road silver - I think you're going to really like the capabilities of a bike w/jackshafted gearing. While acceleration is obv improved what I really think you'll appreciate is the drastic reduction in cruise RPM & thus vibration & noise, making for a much more comfy ride. With the addition of a bit of header wrap & the extended silencer, the ride is quiet enough it's equivalent to factory mopeds, I can even have a convo with another rider - but prolly most important is I can hear other traffic, like a car coming up behind me.

There is a small problem w/the three piece pedal crank & freewheel bearing setup I feel I should give ya a "heads up" about tho, it can be frustrating if you've not encountered it before & can lead to long-term component fatigue issues if not addressed...

The problems I mentioned above w/the shiftkit side plate flex stem from the dependence on utilizing the bottom bracket as part of the engine's drive train, necessitating a freewheel bearing that takes the engine's load. The flex itself can be lessened by simply using an additional lock collar on the outside of the left plate & one on the inner of the right (necessitating a longer piece of 5/8ths keyed shaft ofc) - but as the freewheel bearing is threaded on to a pedal crank w/the sprockets bolted to it, then the pedal crank is pressed on to the square, tapered shaft of the spindle - it's that press fit on a square shaft that's the source of the problem as it is next to impossible to achieve a perfectly centered fit on the square shaft with the supplied aluminum pedal crank arms (perhaps issues w/arm castings, it's variable);

Symptoms in the following vids, note chain movement;

Secondary chain/jackshaft to crank

Tertiary chain/crank to hub;

Pulsing demo ride;

I've replaced everything, a new 3pc cartridge crankset complete with a replacement freewheel bearing, pedal arms & sprockets and then each component individually to verify. Unfortunately, it seems the drive train "pulse" can be lessened, but not eliminated. As it turns out the most successful procedure is simply to press the pedal crank on & test, removing & repressing it back on if necessary, even rotating it to a different face on the square shaft in an attempt to find it's best placement.

Usually with some patience this can reduce the "pulsing" effect to tolerable levels if you encounter it

Last edited by BarelyAWake; 03-27-2012 at 02:05 AM.
Reply With Quote