E-bike hub motor lacing question

[BikeGremlin]

A question I got under the spoke breaking prevention YouTube video:

Hi Relja,now that ebikes are growing could you do some youtube clips on lacing hub motors?,some ebikes with wider flanges use a cross one pattern and some even use 13 straight gauge spokes,alot of hub motors also have narrow flange spacings,I see hardly any clips about lacing ebike hubs cheers

 

[BikeGremlin]

There are (at least) two things to consider here:

1. The optimal number of crosses
2. Lacing technique

1. Optimal number of crosses​

In my wheelbuilding basics article I've discussed the optimal number of spoke lacing crosses. However (as briefly noted in the article), for the small rims (smaller than 559 mm ETRTO or 26" as they're commonly referred to) or for the really large flanges (like hub motor flanges), the optimal number of crosses should be reduced by (at least) 1.

The point is to avoid the spokes entering the rim at a very steep angle (best to stay below 8 degrees), as well as to avoid spokes overlapping the adjacent spoke holes (at the flange).

Some spoke length calculators will provide the info about the rim entry angle of spokes. The calculator I like and use:

https://spokelength-project.com/calculator/

2. Lacing technique​

Regarding the lacing process, the principles are the same as they are for "normal" wheels. Yes, some motor hub wheels are built with thicker spokes - and have thicker flanges with wider holes for such spokes, along with matching rims. Still, again, the lacing principles are the same.

Having said that, motor hub wheels with thick spokes do resemble motorcycle wheels. I've made some videos about motorcycle wheel lacing and building, and those can be helpful if you're dealing with thicker spokes:

• Motorcycle wheel lacing explained & demonstrated
• Motorcycle wheel building basics (goes for bicycles as well)
• (Motor)bike wheel design basics
• Motorcycle spoke & torque wrench set – by Warp9Racing

Relja