Lacing Bafang hub motor

[fitek]

I tried 10mm and 12mm. 10mm is too small, 12mm too big.

So I tried the American sizes...

7/16"-20 was too small, 1/2"-20 fit but very loosely.

Additionally, I now realize that the axle is too big to fit into any of the forks I have. It also is too wide for me to put any sort of washer on the inside to keep the forks from rubbing against the hub motor cover, without spreading the forks wider. I can probably grind out and spread one of my cheapie steel forks, but its too bad as I was hoping to use this motor on my downtube folder and I won't abuse it like this, so the motor will be relegated to some other use.

Grr.

 

[fitek]

The PDF says M12x1.25. Maybe I just didn't find the right pitch at HD and Orchard.

 

[johnrobholmes]

Or the threads are overcut a bit. The last batch I had were a bit tough to start. If you can find a thread gauge for that size it would help ensure proper thread pitch.

 

[methods]

I have built 10 or so wheels now - 5305 into 26" and 24" rims, 9C into 20", 24", and 26" rims. Various regular wheels - 3 cross and 4 cross.

I agree that a good quality 14g spoke is way better than any straight 13g or 12g hub spoke (except maybe those nice ones Justin sells for cheap!).

The 14g spokes bend easily (and then bend pop back ), they dont bind, it is easy to find a spoke wrench that fits, easy to find extra nipples / spokes - and most importantly - you can cut your own spokes .

Average bike shop will charge you >$2/custom spoke. That is $72/wheel !!
For only $160 you can buy your own spoke cutter.
For another $50 you can buy a lifetime supply of high quality spokes!

The biggest hangup I have building wheels is trading off cross for bend... I always want to try to lace a 5305 into a 24" wheel with a 3 cross.... even a 2 cross... problem is that if the spoke bends exiting the nipple it is pointless. I now have to force myself to run a lower cross to keep the spokes straighter.

I would like to say that I have never broken a spoke after thousands of miles - 5305 on 24S hammering, hammering, hammering, with >100A current limits.
Anyone who says 14g is not good enough for a powerful ebike is not having their wheels built right. (or just has bad luck )

-methods

 

[fuz]

Hiya Methods,

Do you have any info on the cutter and spoke supply you mention? I have been thinking about going back to my lbs to have them relace my wheel into a 1x cross pattern. When they originally laced my motor up for me they used a 2x pattern with no dishing. Getting close to 800 miles on my bike and have become very proficient at changing out broken spokes. I bought some higher quality spokes and went with a steel rim (I originally used a fairly flimsy aluminum stock rim to see how I could do with it. Got very experienced at how not to true a wheel). This almost fixed my spoke breakage issue after I rebuilt the wheel but realized that I realllly needed to dish it somewhat. This has worked very well at keeping my wheel nice and centered with all the peddling, but busted a nipple the other night. It seems all of my spoke problems have been related to how much they bend come out of my rims. They either end up cracking the nipples or snapping off the at the threads. Anyway, having a way to experiment with my own spoke lacing seems like a good idea. Frankly I have learned a ton from your posts, (and gotten several GREAT deals from you) and in case no one has said it lately, damn glad you are here.

fuz

 

[fitek]

I have finally started riding a bike with this wheel and it is awesome.

I dunno if I said but I went with 12/14 guage spokes.

It was about $70 for the spokes though!

I'd like to do a dual motor bike so I think I'll pony up for a die to cut the spoke thread.

Any suggestions on the die for the spokes?