Bafang 750w Surley Krampus 29+ Problems, Tis The Season For Upgrades
So I installed a Bafang 750w BBSO2b motor on a 2017 Surley Krampus 29"x3" Mountain bike and it's GREAT!
I weighed more in the beginning, figure 350lbs. Its been up the mountain trails in Colorado and California. When going up the steep hills I have to pedal and help the motor out.
I was able to fit a 28t chain ring which I was able to mount behind the chain ring adapter t bring my chain offset down a little bit. Long story short, the motor is slightly spaced out maybe a quarter of an inch and the chain is just offset too much on the two largest gears of the 11-42t cassette. This means I'm stuck using the second from the largest, a 32t gear as my biggest.
My biggest problem is heat, the motor is struggling with the weight and lack of gear.I'm thinking I could upgrade my cassette to an 11-52t. My thoughts are, with this setup it would put me on a 40t gear at the same gear location and that should help a lot.
I assume this may not be enough and heat is still going to be an issue.
I did write to Bafang about the heat issue and asked what they recommend, they actually responded by one of their tech guys and he gave me a lot of info and said it was normal considering the use, maybe they were being humerus when they advised me just not to use it up hill... lol helpful, but i see their point. shortly after I had a breakdown. I'm currently awaiting parts from china, a motor core, because I got an 08 H hall sensor error. The coils all look fine as best i can guess and it never shut down completely due to heat, it wasn't even that hot when it failed, but I guess its been pushed a little bit, only had maybe 100 miles of use on it. Internals all look perfect, I'm going to re-grease with mobile 28 as people recommend.
Now I'm thinking as my next move what about a second motor, a hub motor, perhaps something I can use with the same battery. I haven't done much research yet, I figured I would start here and see if anyone has any suggestions. It would be nice to have it for up hill climbs and just as a backup wouldn't hurt.
The alternative to this is to go with the 1,000w Bafang BBSHD motor, or perhaps another motor thats better? The cassette and 1000w motor upgrade might be enough to get the job done.. I do like the idea of a second motor though.... ahhh decisions decisions
If anyone has any other suggestions that might help it would be appreciated.
Last edited by TRIBUNAL; 12-07-20 at 10:34 PM.