Lacing 48 spokes with 36 spokes motor HELP!

[vadikb]

I got weird fat bike with 48 spokes and I really need help lacing it with my newly purchased motor that has holes for 36 spokes.

I really do not want to drill any extra holes on my motor, so what would be the option? Can I skip 12 spokes?

How can I calculate what spokes length do I need ? Is there a formula or a website for such thing? I really appreciate some help on this ! Dimensions and pics attached.

 

[Drunkskunk]

It is possible, just damn hard. You'll probably want to read the whole page for some background, but the end of this page deals with the 36 hub, 48 rim hole issue and how to calculate the difference. http://www.sheldonbrown.com/special-spoking.html

 

[LewTwo]

Divide your numbers by two and you have 24 and 18 holes respectively.
That means 6 missing spokes spread across 9 intervals on each side.
That math does not work well.

Two other alternatives:
1) Have the existing holes in the hub filled with weld. Then have a new set of 48 holes machined.
2) Have a pair of bolt on 36 x 48 holes adapter plates made for the hub.
Neither would be cheap and both would require a good machinist.

 

[MadRhino]

Buy another rim, unless you value your time 2$ an hour. :wink:

 

[vadikb]

Thank you for you all your help.

I did not think it would be this difficult. I thought buying a new rim and tossing away my current one would be a waste, but I guess i got no other option. :|

 

[Lurkin]

Buy a new rim, build it correctly with 36 spokes.

Sell 48 spoke rim on a forum? win. 8)
Or sell the motor and buy one with 48 spoke holes?. win. 8)

 

[Mundo]

Never heard of a hub motor with 48 spoke holes, got a link?

 

[Lurkin]

Neither. I would contact a hub manufacturer and get one custom.

 

[amberwolf]

Or build a pair of adapter rings with 36 holes in teh inner circumference, to bolt to the spoke holes in the hub flanges, and 48 holes in the outer circumference, to lace up to the 48 hole rim.

This would also widen the flange distance, so you may avoid a potential issue with wide rims, where the nipple holes in the rim are space so far apart that you have no angle from them to the flanges, so the wheel has little or no side-load strength without cross-lacing from side to side.