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Old 08-22-2009, 10:14 PM
Nashville Kat's Avatar
Nashville Kat Nashville Kat is offline
Motorized Bicycle Elite Member
Join Date: Apr 2009
Location: Jacksonville, Florida
Posts: 1,403
Default Re: Can a flip-flop hub save my spokes?

A flip/flop hub would make the mounting easier- They have the same diameter on each side at the main section, as far as the diameter of the hub where a freewheel, a single fixed track cog, or our sprockets fit-
they usually have a freewheel on one side (with more axle spacing from side to side) and the track cog on the other side. On the outside of the track cog, is a set of threads of smaller diameter for the lock ring- and yes it is reverse left-hand thread-that will lock our sprocket on and not spin it loose- (A bottom bracket lockring is the same diameter as this)

Of course our sprockets just sit on the hub and don't thread- (What I'd like to find is a 34 or 36 tooth track cog--we'd be all set! But trackies usually don't ride gears that small.) Also generally, it appears that our sprockets are just a little more narrow than the track cog- so a spacer of some kind is needed- perhaps the rubber piece then- or perhaps a small (say a 14 tooth) track cog itself would work- if there is enough spacing for the lockring- and then the bolts for our sprocket to go through the high flange
I've wondered if a sprocket could be welded or driven somehow and attched to the side of a single track cog.


So our sprockets don't thread down like the track cog but with a spacer, should be wedged and locked laterally by the reverse thread lockring-

I've inspected all this, but haven't yet actually done a build with a floppie- but I think it would be the best setup outside of a 36 track cog itself)

Then the only other factor is driving the sprocket forward with the chain and turning the wheel-

A LARGE FLANGE trackkie flip/flop seems the most ideal for the most efficient and lightweight mount- But you'd have to drill your sprocket to fit the usual openings in the large flange- Then (it appears) minimal nuts and bolts could be used to bolt your sprocket almost directly to the hub- WITHOUT getting anything on the spokes-

I've drilled a really light 34 tooth sprocket for the flanges on a Schwinn ten-speed Traveler I have- (See my thread here titled "Your bike is a grinding wheel"- I'll bump it up now- there's a picture of my hub and sprocket)

I'll put it here too-

A floppie is the best setup, but most older style alloy road hubs will easily grind down a little bit to accomodate our sprockets- and the large flange may be the best to bolt to with just rubber spacing instead of stressing the spokes. Just no lockring.

I'm also gonna bump my ancient thread on our need for a locking freewheel- which turns like a normal freewheel for freewheel pedalling, but then locks up to restart our motors

good luck!

Last edited by Nashville Kat; 08-22-2009 at 10:51 PM.
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