Post by tomac on Oct 23, 2003 10:48:21 GMT 10
This is a cross-post from biketrials.com board, where people were whinging that their acs freewheels had a lot of side-to-side play even after tightening, and that they were making "funny noises" (the mechanic's phantom - "what SORT of funny noises dipshit ?!!"). Anyway I figured that people in canberra didn't necessarily use that board, and some certainly have problems with freewheels. Follow these instructions (even if not new, you can still treat your freewheel and it should work fine) for any brand of freewheel, but bear in mind that some might have a slightly different construction to ACS, which this is based on.
Appréciez !
The ACS claws freewheels vary from each to another because they use spacers inside the freewheel to accomodate for the imprecise machining/stamping/casting/whatever methods they use. the lockring (which, on a rear hub, faces outward, but on front freewheel cranks faces inwards making it harder to get at) screws down onto a pile of round spacers so that the lockring doesn't press down onto the ring with the cog teeth on the outside and the pawl teeth on the inside. If you still have a lot of side-to-side wobbling after tightening the lockring right down (it uses a pin tool, but you can use a piece of coat-hanger grade wire bent in the right way and with the ends ground down slightly - you don't need to do it up uber tight after all) then you can take the lockring right off and remove one of the tinfoil-like spacers from the inside so that the lockring pushes down further. Of course if you remove too much spacer then you'll restrict the turning movement of the freewheel itself and go nowhere. Up to about 2 mm of side-to side play is fine, that's not enough to interfere with the pawls or the bearings.
Now as for preparing the freewheel you probably don't have to rebuild the whole thing off the shelf. If you are using it for trials however on a front freewheel the pedalling forces you put on it will try to unscrew the lockring (because it's mounted backwards on your cranks to the intended mounting aaaahhh....) so what you have to do (you can screw it onto your crank to do this, that's fine) is take the top cap off while the freewheel is lying on its back (with the lockring facing up towards you) and loctite the bejesus out of the thread that you just unscrewed. While you're there you may as well put some lube on the pawls - the bearings should already have some firm grease there out of the factory but if not - grease em up (always always lube moving parts unless you're told specifically by the manufacturer not to - or you're talking about brake pads). I'd suggest using thicker stuff so it stays put rather than interfering with your loctite - which will not set if there is grease (or air or water for that matter) present. When you take the topcap off however, don't pull up the ring with the teeth on the outside (this also has the pawl's teeth on the inside, and is a single piece with two bearing races as well - we'll call it the teeth ring) otherwise the SECOND race of bearings, which you may not have noticed, will fall out all over the ground and I believe there are at least 70 of the suckers in there - and a lot of hassle to reinstall them. So yeah, loctite the top cap's thread so it doesn't come loose, using as much of the strongest loctite as you can find, then tighten the top cap down heaps (and don't forget, it's a REVERSE THREAD so anti-clockwise tightens it!), and leave it for 24 hrs before riding it, otherwise the loctite will never set as it will be agitated with the grease from the bearings and pawls. Every now and again drop some tri-flow or something thicker in through the gaps to lubricate the pawls (after your loctite has set obviously) and if your top cap comes loose on the "trail" then you can stick something (a pen, a small screwdriver, piece of wire, key or whatever) into one of the two holes in the top cap, rest the item against your chainstay, and backpedal. This works of course because it's a reverse thread.
if you prepare your freewheel like this it will treat you well.
phew
- Joel
PS these same principles work for the shimano freewheel, which I think has less pawls etc but is the same in principle.
Appréciez !
The ACS claws freewheels vary from each to another because they use spacers inside the freewheel to accomodate for the imprecise machining/stamping/casting/whatever methods they use. the lockring (which, on a rear hub, faces outward, but on front freewheel cranks faces inwards making it harder to get at) screws down onto a pile of round spacers so that the lockring doesn't press down onto the ring with the cog teeth on the outside and the pawl teeth on the inside. If you still have a lot of side-to-side wobbling after tightening the lockring right down (it uses a pin tool, but you can use a piece of coat-hanger grade wire bent in the right way and with the ends ground down slightly - you don't need to do it up uber tight after all) then you can take the lockring right off and remove one of the tinfoil-like spacers from the inside so that the lockring pushes down further. Of course if you remove too much spacer then you'll restrict the turning movement of the freewheel itself and go nowhere. Up to about 2 mm of side-to side play is fine, that's not enough to interfere with the pawls or the bearings.
Now as for preparing the freewheel you probably don't have to rebuild the whole thing off the shelf. If you are using it for trials however on a front freewheel the pedalling forces you put on it will try to unscrew the lockring (because it's mounted backwards on your cranks to the intended mounting aaaahhh....) so what you have to do (you can screw it onto your crank to do this, that's fine) is take the top cap off while the freewheel is lying on its back (with the lockring facing up towards you) and loctite the bejesus out of the thread that you just unscrewed. While you're there you may as well put some lube on the pawls - the bearings should already have some firm grease there out of the factory but if not - grease em up (always always lube moving parts unless you're told specifically by the manufacturer not to - or you're talking about brake pads). I'd suggest using thicker stuff so it stays put rather than interfering with your loctite - which will not set if there is grease (or air or water for that matter) present. When you take the topcap off however, don't pull up the ring with the teeth on the outside (this also has the pawl's teeth on the inside, and is a single piece with two bearing races as well - we'll call it the teeth ring) otherwise the SECOND race of bearings, which you may not have noticed, will fall out all over the ground and I believe there are at least 70 of the suckers in there - and a lot of hassle to reinstall them. So yeah, loctite the top cap's thread so it doesn't come loose, using as much of the strongest loctite as you can find, then tighten the top cap down heaps (and don't forget, it's a REVERSE THREAD so anti-clockwise tightens it!), and leave it for 24 hrs before riding it, otherwise the loctite will never set as it will be agitated with the grease from the bearings and pawls. Every now and again drop some tri-flow or something thicker in through the gaps to lubricate the pawls (after your loctite has set obviously) and if your top cap comes loose on the "trail" then you can stick something (a pen, a small screwdriver, piece of wire, key or whatever) into one of the two holes in the top cap, rest the item against your chainstay, and backpedal. This works of course because it's a reverse thread.
if you prepare your freewheel like this it will treat you well.
phew
- Joel
PS these same principles work for the shimano freewheel, which I think has less pawls etc but is the same in principle.