Spoke count for disc brake wheelset?

[ms6073]

So in terms of spoke counts for cyclocrossuse wheelsets with 160mm rotors for a ~79kg rider, what are the considerations/limitations of 24/24 versus 24/28 versus 28/28.

[StradaJon]

I would opt for 28 / 28 ideally with a spoke designed for use with Disc braking such as a DT Swiss Revolution or the Sapim CX Ray to keep the weight down. The torque at the hub end of the spoke is higher than cantilever when under braking.

[mjduct]

that explains why I keep busting them at the hub on my 29er!

[ms6073]

So are loads at the hub for disc wheels handled differently based on hub design and spoke patterns? I notice both Easton and Reynolds are marketing sub 1500 grram carbon tubeless 29er wheelsets featuring 24/24 spoke counts with hubs that use straight pull spokes.

[StradaJon]

Yes Michael - think about the torque being applied to the hub flange when you pedal hard and then apply the disc brake. The flange and spoke needs to cope with these forces. There is more twist being applied to the area close to the hub flange on a disc brake than out at the rim on a cantilever brake.

In fact, Sapim have released the D-Light specifically for disc applications such as CX or 29er.

[ms6073]

In fact, Sapim have released the D-Light specifically for disc applications such as CX or 29er.

Ah, good to know. So if sourcing hubs with straight pull spokes, then sounds like 24/24 or 24/28 would be a safe bet, otherwsie for conventionalal hubs sounds like I need to consider 3-corss with a minumum of 28/28 and Sapim D-Light spokes. At this point, if I were building a single wheelset, I use Enve or Zipp rims but got to replace 3-4 sets of Easton EC90 SL carbon tubulars so cost is a fact but I have read numerous possitive comments at another cycling related forum about 50mm carbon tubulars with 23mm width from Farsports and Yishun in China.

[joeyruan]

Yes Michael - think about the torque being applied to the hub flange when you pedal hard and then apply the disc brake. The flange and spoke needs to cope with these forces. There is more twist being applied to the area close to the hub flange on a disc brake than out at the rim on a cantilever brake.

In fact, Sapim have released the D-Light specifically for disc applications such as CX or 29er.

+1