niosoliton
1 µW
- Joined
- Mar 26, 2013
- Messages
- 1
Hi all,
I build wheels for e-bikes and pedal-power generators, usually 700cc and 26" wheels using meausred ERD, hub dimensions, and 12g spokes. That works well, giving accurate spoke lengths.
However, I recently built a radial 20" wheel and motor hub using the same spoke calculators, and the recommended was 87mm spoke (very short) was still too long by several mm. I triple checked various spoke calculators, checked measurements, and did the math myself on paper. The result was the same. Apparently this has been a problem in the shop previously with small wheels and short spokes. I suspect a small rim and short spoke with a big hub has tighter tolerances and is subject to discrepancies that usually wash out, such as inner/outer lacing, spoke flex at the flange, etc.
My question is: has anyone else had this problem, and can they recommend a solution in the form of a better spoke length calculator accounting for small wheels and large generator hubs?
My present solution is to find a length which works, and bias future spokes for 20" wheels the same amount, but I'd prefer an accurate calculator.
Thanks,
Nio
I build wheels for e-bikes and pedal-power generators, usually 700cc and 26" wheels using meausred ERD, hub dimensions, and 12g spokes. That works well, giving accurate spoke lengths.
However, I recently built a radial 20" wheel and motor hub using the same spoke calculators, and the recommended was 87mm spoke (very short) was still too long by several mm. I triple checked various spoke calculators, checked measurements, and did the math myself on paper. The result was the same. Apparently this has been a problem in the shop previously with small wheels and short spokes. I suspect a small rim and short spoke with a big hub has tighter tolerances and is subject to discrepancies that usually wash out, such as inner/outer lacing, spoke flex at the flange, etc.
My question is: has anyone else had this problem, and can they recommend a solution in the form of a better spoke length calculator accounting for small wheels and large generator hubs?
My present solution is to find a length which works, and bias future spokes for 20" wheels the same amount, but I'd prefer an accurate calculator.
Thanks,
Nio