New 8-speed freewheel too large for axle



marckx

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Sep 24, 2004
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I just replaced the drivetrain (crankset, chain, SRAM/Sachs freewheel) on an old 8-speed bike with steel frame 130 mm spacing. The problem is the freewheel, tightly on the thread, is about 3 mm too wide -- the drive-side lock-nut is recessed beneath the outside of the small cog.

I tried putting two thin washers on the axle which works in theory, but doesn't leave much axle sitting in the drive-side drop-out.

I'd be willing to sacrifice the high gear (small cog) by taking it off with a pair of chain whips. My question there is: do the other cogs on the freewheel depend on that cog?

Or move the axle over 3 mm with spacers and a smaller locknut on the non-drive side. I assume that would require a round of dishing the wheel true. (right?)

Mark
 
marckx said:
I just replaced the drivetrain (crankset, chain, SRAM/Sachs freewheel) on an old 8-speed bike with steel frame 130 mm spacing. The problem is the freewheel, tightly on the thread, is about 3 mm too wide -- the drive-side lock-nut is recessed beneath the outside of the small cog.

I tried putting two thin washers on the axle which works in theory, but doesn't leave much axle sitting in the drive-side drop-out.

I'd be willing to sacrifice the high gear (small cog) by taking it off with a pair of chain whips. My question there is: do the other cogs on the freewheel depend on that cog?

Or move the axle over 3 mm with spacers and a smaller locknut on the non-drive side. I assume that would require a round of dishing the wheel true. (right?)
Mark

Before you get to far with this project you might want to see if another 8 speed freewheel will work without the clearance problem.
Andrew Muzi and Sheldon Brown have shops that deal with this application daily.
Your statement of move the axle over 3 mm with spacers and a smaller locknut on the non-drive side & dishing the wheel to center between the locknuts could apply if you can't get a freewheel that provides proper clearance. What is the clearance like at the spoke side between the largest cog and your spokes?

SRAM freewheels use 5.0 mm spacing on 8 speed, while Shimano 8 speed uses 4.8 mm. This would result in 1.4 mm difference in width, if I am awake enough to apply my math correctly.
 
daveornee said:
Before you get to far with this project you might want to see if another 8 speed freewheel will work without the clearance problem.
Andrew Muzi and Sheldon Brown have shops that deal with this application daily.
Your statement of move the axle over 3 mm with spacers and a smaller locknut on the non-drive side & dishing the wheel to center between the locknuts could apply if you can't get a freewheel that provides proper clearance. What is the clearance like at the spoke side between the largest cog and your spokes?

SRAM freewheels use 5.0 mm spacing on 8 speed, while Shimano 8 speed uses 4.8 mm. This would result in 1.4 mm difference in width, if I am awake enough to apply my math correctly.
Your math sounds right. Spacing was a factor I had not considered. My LBS just said '8-speed is 8-speed' when I brought my wheel in. Since I got the freewheel from Harris cyclery it'll take too long to send it back and shop around for another. Shifting the axle over seems the way I'll go. Taking off the small cog to give space seems a bit drastic, even if it the freewheel would remain intact.
 

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