Wheelbuilding Spoke Length Advice


Likes Dirt
I'm somewhat of a novice wheel builder, having only built a couple of sets of wheels, so looking to confirm my calculations with someone who actually knows what they're doing. Have used Sapim, WheelPro and DT Swiss Calculators, and think I have adjusted for rim offset correctly but was hoping someone with a bit more knowledge could confirm I'm on the right path as haven't built with offset rims before.

Plan is to built with Sapim race spokes, Sapim Polyax 12mm brass nipples.

Details are as follows:

32 spoke, 3 cross for both.​
Front Rim: Light Bicycle AM933 Recon Rim​
ERD: 583mm (not including nipple head dimension - whatever this means?)​
Offset: 3mm​
Front Hub: Hope Pro 4 Boost​
Spoke PCD: 57mm​
Non-Drive Side Offset: 25mm​
Drive Side Offset: 33mm​
Spoke Hole ID: 2.6mm​
Rear Rim: Light Bicycle EN733​
ERD: 537 (not including nipple head dimension)​
Offset: 2.7mm​
Rear Hub: Hope Pro 4 Boost​
Spoke PCD: 57MM​
Non-Drive Side Offset: 35mm​
Drive Side Offset: 22mm​
Spoke Hole ID: 2.6​

Assuming I've calculated it properly, each spoke calculator pretty consistently recommends roughly 282mm spoke length on both sides for the front wheel.

However rear is a bit more iffy. Different calculations have it at:

Non-Drive: 259.35, 260, 259.6​
Drive Side: 258.65, 259, 258.8​

Non-drive seems sensible to go with 260mm spokes, but for drive side am I better going for 258 or 260mm spokes given only 2mm increments available?


call me Cáitín
4mm means just in the head or bottomed out, ideally you want it to be basically 1mm from bottomed out when tensioned correctly.

Sapim race are stretchy spokes, I have built a shit load with DT Revos, Supercomps, Sapim CX rays and a few with Sapim races.

I would round down to be honest.

The big ticket number here is the ERD, is it 100% correct, you could be way out using manufacturer info.

I am pretty new to fat DT Comps... where have they been all my life. So easy to build with if you are not counting grams.

Next set will have Aero Comps, built them before on an AM wheelset, they are also pretty easy to build.