Bicycle Mechanics - Wheel Building - Spoke Length Help

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EagleEye
08-25-03, 02:15 PM
I'm looking into building my first wheelset. I have a set of Ultegra hubs and Mavic CXP21 rims. I did spoke length calculations on the DT site and came up with this:

32 holes, 3 crossings:

Front (100mm)
Left = 295.4
Right = 295.4

Rear (130mm)
Left = 294.2
Right = 292.7

When I looked for the spokes, they are all whole mm, like 292, 293, 294, 295, and so on.

Is the spoke length calculations right? What length do I buy? Do I round up and buy 296mm for the front wheel and 295 and 293 for the rear?

Obviously, I'm new at this and just don't want to order the wrong stuff.

Thanks.

sch
08-25-03, 07:42 PM
Round up or down to the nearest mm. using standard rounding rules. Most of the time there is enough space in the rim to absorb any extra that protrudes very far beyond the end of the nut. I believe the CXP21 is deep enough for that not to be a problem. The spoke will not be too short if the calculator is otherwise correct. I haven't checked your numbers. My reply is based on my own wheel building experience. Steve
John E
08-25-03, 08:26 PM
I concur with Steve, although I always round down to the nearest mm, to make sure the spokes do not protrude through the nipples. Using slightly shorter spokes on the drive side is a very nice professional touch, and it can actually help you set up the initial dish by eye and feel.