mbl73

Hi. I have read a bit about wheelbuilding, far from being an expert, but I begin to get an idea what to pay attention to. I haven‘t found answers to a few questions though.

My rims‘ ERD is 611.5mm (28“) and my motors PCD is 173.75mm. 36 spokes. The tech doc of the motor (zehus halo) says, that they „strongly“ recommend a 1-cross build for 24“-29“ wheels and that they „strongly“ recommend to insert all spokes from outside to inside. I don‘t understand why. Whatever I find in the internet, spokes‘ inside/outside orientation is alternating. And why wouldn‘t it be better to do a 2-cross build with a 28“ rim with 36 holes. I don‘t think the motors PCD is too big for that.

The front wheel will be the same rim, but 32 holes. PCD of the hub is 58mm. I think 3-cross is the best way to go. But… if it is true that it’s best to build the rear wheel with 1-cross, might it be better to build the front wheel as 2-cross for any reasons?

Both wheels have disc brakes.

Thanks for enlightening me :-)

Trakhak

The motor's PCD (pitch circle diameter, referring to bolt heads, etc.; I had to look it up, since I've never seen the term used with regard to bicycle wheel building) is likely irrelevant, unless it's identical to the spoke hole circle diameter.

I wouldn't expect 2X to provide any significant advantage over 1X in this application.

In addition to whatever answers, speculative or otherwise, people provide in this thread, it might be worth contacting the manufacturer for clarification. Many of us here would be interested in the manufacturer's reply.

Doc_Wui

Building both wheels then?

I believe that the reason they use crossing patterns is that there's strength gained from having the spokes touch at the cross. I've read that a radial pattern, which is no crossing, is the weakest wheel.

If Zehus tells you 1X with outside spokes, they're saying that an inside spoke won't touch the other spoke at the cross. I'd follow their recommendation. When I build wheels now, I do 1X with heads outside. When I've looked at various 26" and 28" hub motor wheels, the crosses never touch when they alternate the heads.

I don't think you will be able to thread spokes thru a hub motor build with a 2X.