Re-spacing the rear axle
Posted: 12 Dec 2012, 10:37am
Hello,
I'm trying to replace the rear (26", solid-axle) wheel on a bike with 130mm rear dropout spacing (the bike uses a six-speed freewheel, and is a perfectly adequate workhorse, more-or-less a hack bike).
The replacement wheel has an over-locknut distance (OLD) of 135mm, so I can get it into the frame with (quite) a bit of a struggle, but this situation is not ideal. It makes changing tyres or repairing tubes no fun at all.
Examining the wheel, I realized that the over-locknut distance is governed by the axle spacer on each side, between the cone and the locknut. The drive side has a 14mm spacer, the idle (non-drive) side a 12mm spacer, giving a total spacing of 26mm. Each spacer has an outer diameter of 15mm, and an inner diameter of 10mm.
It strikes me that if I can reduce the total spacing to 21mm, then the over-locknut distance will fall to 130mm, and I'll be able to insert and remove the wheel with ease, making repairs much less of a chore.
I could move the 12mm spacer I have to the drive side, and insert 9mm of spacing on the idle side. This cuts 2mm off the drive side, and 3mm off the idle side, which slightly changes the symmetry of the wheel. Will that be a problem in practice? Would I do better to take 3mm off the drive side, and 2mm off the idle side? That would mean I couldn't reuse the 12mm spacer, so the cost would rise.
Spacers seem moderately hard to find (I imagine this kind of "conversion" isn't done that often). I see Practical Cycles currently has some on its eBay shop, and they seem to be marketed for people fitting 130mm hubs into 135mm frames (that's the opposite of what I'm doing). They're priced per spacer, with sizes from 1mm to 5mm, plus 0.5mm, for the true perfectionist.
If 12mm plus 9mm will work, then I'll only need to buy a 5mm and a 4mm. If I got for 11mm plus 10mm, then I'll need to buy three 5mm and one 1mm spacers. However, the (small) extra cost will be worth it if it means a better chainline.
Can anyone please advise me on this conversion? Am I worrying too much about a non-issue?
One colleague suggested simple hacksawing off part of the 14mm spacer, but I'm not sure I can achieve the necessary accuracy, and I don't really have the tools. In any case, that would leave me with no easy way to return the wheel to 135mm spacing in the future, in the case where a 135mm-spaced frame is purchased.
I've read Sheldon Brown's page on cold-setting a frame, but why go to all that trouble and risk if I can just respace the over-locknut distance?
Many thanks.
Reference info: http://sheldonbrown.com/frame-spacing.html
I'm trying to replace the rear (26", solid-axle) wheel on a bike with 130mm rear dropout spacing (the bike uses a six-speed freewheel, and is a perfectly adequate workhorse, more-or-less a hack bike).
The replacement wheel has an over-locknut distance (OLD) of 135mm, so I can get it into the frame with (quite) a bit of a struggle, but this situation is not ideal. It makes changing tyres or repairing tubes no fun at all.
Examining the wheel, I realized that the over-locknut distance is governed by the axle spacer on each side, between the cone and the locknut. The drive side has a 14mm spacer, the idle (non-drive) side a 12mm spacer, giving a total spacing of 26mm. Each spacer has an outer diameter of 15mm, and an inner diameter of 10mm.
It strikes me that if I can reduce the total spacing to 21mm, then the over-locknut distance will fall to 130mm, and I'll be able to insert and remove the wheel with ease, making repairs much less of a chore.
I could move the 12mm spacer I have to the drive side, and insert 9mm of spacing on the idle side. This cuts 2mm off the drive side, and 3mm off the idle side, which slightly changes the symmetry of the wheel. Will that be a problem in practice? Would I do better to take 3mm off the drive side, and 2mm off the idle side? That would mean I couldn't reuse the 12mm spacer, so the cost would rise.
Spacers seem moderately hard to find (I imagine this kind of "conversion" isn't done that often). I see Practical Cycles currently has some on its eBay shop, and they seem to be marketed for people fitting 130mm hubs into 135mm frames (that's the opposite of what I'm doing). They're priced per spacer, with sizes from 1mm to 5mm, plus 0.5mm, for the true perfectionist.
If 12mm plus 9mm will work, then I'll only need to buy a 5mm and a 4mm. If I got for 11mm plus 10mm, then I'll need to buy three 5mm and one 1mm spacers. However, the (small) extra cost will be worth it if it means a better chainline.
Can anyone please advise me on this conversion? Am I worrying too much about a non-issue?
One colleague suggested simple hacksawing off part of the 14mm spacer, but I'm not sure I can achieve the necessary accuracy, and I don't really have the tools. In any case, that would leave me with no easy way to return the wheel to 135mm spacing in the future, in the case where a 135mm-spaced frame is purchased.
I've read Sheldon Brown's page on cold-setting a frame, but why go to all that trouble and risk if I can just respace the over-locknut distance?
Many thanks.
Reference info: http://sheldonbrown.com/frame-spacing.html