hub swap question

[mattsccm]

I want to rebuild an old freewheel wheel, ditching the Maillard rear hub and replacing it with a Campag record. Just to make a matching pair of wheels. The diameter of the hub flange is less than 1mm smaller on the Campag rim and the same for the holes. Is this likely to cause issues if I reuse the spokes? Currently I can see no thread where the nipples show through the rim.
The width of the hub is the same . I suppose that in theory the spokes need to be 0.5 mm longer. ( if the were radial which they are not) 36 spokes ,3x

[Brucey]

if the spoking were full tangent, the hub flange diameter becomes (over a small range) completely irrelevant. 36x3 isn't full tangent but it is close enough that you ought to be able to swap hubs as you propose with no worries.

If you require some further reassurance, you can enter your measured dimensions into a spoke calculator program.

cheers

[NATURAL ANKLING]

Hi,
Fitting shorter spokes with same hub (re-spoking wheel with shorter spokes) is more a problem than a smaller spoke (PCD) hole circle because of the geometry as said above.

After building wheels the error in actual spoke end will be +/- 1mm, up to max.

Just watch for spoke threads showing either end of nipple.

[Brucey]

If radially built the spoke length error will be 0,5mm as mattsccm suggests; however the actual error in the spoke length in this case will be a small fraction of 0.5mm, (about 0.2mm in fact) because of the near-tangent effect.

cheers

[NATURAL ANKLING]

Hi,

Hi,
Fitting shorter spokes with same hub (re-spoking wheel with shorter spokes) is more a problem than a smaller spoke (PCD) hole circle because of the geometry as said above.

After building wheels the error in actual spoke end will be +/- 1mm, up to max.

Just watch for spoke threads showing either end of nipple.

That looks wrong now I read it
"After building any wheels the error in actual spoke end will be +/- 1mm, up to max. Compared with a spoke calculator" Never perfect.
And it should of been at end of post.......sorry.

[Brucey]

sorry, perhaps I misunderstood what you were saying. In the OP's case he's interested in the error caused by the new hub diameter, but using the same spokes and rim as previously.

My suggestion of using the spoke calculator is that if you manually enter a 1mm change in hub diameter (keeping the other parameters the same) you can see what effect that has by itself.

cheers

[531colin]

................. Is this likely to cause issues if I reuse the spokes? ...............

I would keep the spokes in 4 sets, that is inside and outside of the 2 flanges, as the spoke elbows will have taken a set to match their situation.

[NATURAL ANKLING]

Hi,

sorry, perhaps I misunderstood what you were saying. In the OP's case he's interested in the error caused by the new hub diameter, but using the same spokes and rim as previously.

My suggestion of using the spoke calculator is that if you manually enter a 1mm change in hub diameter (keeping the other parameters the same) you can see what effect that has by itself.

cheers

Agree.....I wasn't opposed at all.....even if I sounded that way.......I said sorry...........no issue.

Edited....erk now I am confusing myself............just ignore me

[mattsccm]

Worked fine. I had the spokes batched so that they went back in the same place. Good job as I was too impatient and wait for replies and had the wheel apart within a few minutes of posting
Ta