I recently bought a new 2023 Norco Fluid hardtail. It's a mid level 29 er. It's reasonably spec'ed out with hydraulic brakes and has a dropper seat post which I find very useful. Rear 12 speed 12 - 52 gearing. The bike shop installed a rear rack that was going to hold one of my rack mount 48V batteries. My spare BBSO2 is a 68 to 73mm version and the bottom bracket on the bike measured 68mm so I thought it would fit.
However the chainstays flare outwards just behind the bottom bracket so once the motor was installed and shimmed enough for clearance 2 issues arose. 1st only enough threads to barely put the large nut on that keeps the motor tight to the bottom bracket. Then the chain line was way out of line. So a 18mm offset chainring was installed to see if the the chainline would improve. Still not great because the motor now needed a shim to move it away from the bottom bracket to keep the chainring teeth from rubbing on the chainstay. A solution I guess would be order a 100 mm motor or maybe a CYC but they are expensive. Anyone here try a CYC yet?
However the chainstays flare outwards just behind the bottom bracket so once the motor was installed and shimmed enough for clearance 2 issues arose. 1st only enough threads to barely put the large nut on that keeps the motor tight to the bottom bracket. Then the chain line was way out of line. So a 18mm offset chainring was installed to see if the the chainline would improve. Still not great because the motor now needed a shim to move it away from the bottom bracket to keep the chainring teeth from rubbing on the chainstay. A solution I guess would be order a 100 mm motor or maybe a CYC but they are expensive. Anyone here try a CYC yet?