Spoke length
 

Hi!

I know this is a rather silly question but the case is that I have bought a second-hand bicycle and need to know the exact lenghts for a spoke in front wheel and in rear wheel, as I am planning to buy some spares. I also need to find out the nipple lenght.

The case is that the wheels are really well-built and the hubs I have are Shimano dynamo hub (front) and Rohloff (rear), so in this case there are only 2 different spoke lenghts.

So Is there a reliable way to find out these information?

Yes. The absolute best way is to loosen and remove a spoke from each wheel and measure it before putting it back. :)

..but it's not hard at all for a bike shop person to measure pretty accurately without removal. I always just measured from inside of the head to the rim and then added 2mm.

Read the manual ? at least R'off offers a spoke length for selected rims on a chart.

May I suggest you not preface your question by saying it's silly? That gives people the right to agree with you.

It sounds to me like you have some doubt that the wheels are really well-built. If they were, there is very little chance that you will ever need spare spokes.

The only reliable way to find your spoke and nipple lengths is to remove one set from each wheel and measure. This of course assumes the original build used the correct spoke lengths. Everything else is an estimate. But that might be close enough for something you will probably never use.

Be aware that it's likely your spokes are not all the same length. So you can't just buy one length and be ready for something you may never have happen again.

Hi!

Thanks for quick replies. I have a Mavic A319 rims and Mavic recommends 12mm spokes (which I indeed have). Mavic also tells the ETRTO size: 622 x 19C and according to Rohloff manual spoke lenght in this case (32 holes) is 268mm if I use the cyclecycle.info -database.
Front I have Shimano DH-3N80 Dynamo hub (32 holes) and according to this site spocalc.htm from Sheldon Brown the spoke lenght in front wheel is 289,60mm.

Nevertheless, I have studied "Professional guide to wheel building" by Roger Musson and he said that you should not trust the data provided by the manufacturer but instead buy the hubs and rims first and then measure everything. After that use the formulas/calculators provided to find the adequate spoke lenghts.

Moreover I'm not able to post URLs etc. because I have not written enough messages.

I use the spocalc site and find the info more than adequate to build a reliable wheel.