Hi, I've just bought a Tongsheng mid-drive motor and I am having a problem finding chainrings with enough offset I need one with 24mm to bring the chain closer to the frame but I cannot find one anywhere, Does anyone know where I can get one.
top of page
bottom of page
I too am hoping to have a better chain-line for my Tong Sheng Surly Bridge Club build (with a 73mm BB) From what I understand from reddit reviews with a bunch of different bikes with the problem have a good number of folk just say "well I don't use the granny gears that much any way" (and they just don't shift into their grannies).
Hmm, less than perfect, right? Some of the responses mentioned spider BCD convertors to change out the size of the available chainrings / offsets, enabling persons to tap into other possibilities for chainrings diffent than the ones offered by Tong-Sheng (and after-market Tong-Sheng). Frustratingly the links were to EcoCycles out of Nashville, and currently their website is under construction. With an "Opening Soon" banner. It's been that way for a while now!
BUT if you do find a solution? Could you post it here? That would be great if you did.
OH! And on the possibility you're putting the spider on the wrong side? (The spider for the chain ring being right next to the motor = Putting the chain ring effectively a little further out than you need to? Correct it. Get that chainring right up against the motor and the spider right next to the outside / crank / peddle. And don't be embarassed, I've done that mistake before!
As an aside, they've designed the Tong Sheng to "effectively" allow two chainrings which is pretty unique to mid-drives, but I can't see an efficient way to do it, because of the outward travel of the chainline once the motor is installed. So what they suggest is to use two different sizes of their stock chainrings on either side of their spiders. In practice I can only get it to work at all with one chainring on the inside-of-the-spider position.
Hope this helps!