d8veh wrote: John in CR wrote:
MadRhino wrote:You have enough axle left on both side, to add thick torque plates. They could be bolted or glued, or both. Easy job.
Glued??? Please don't tell me you're part of the "let's get someone killed" crew. Would you ride a glued together bike?...Of course not, and neither would the guy profiting on that ridiculous idea.
Aeroplane and car manufactirers are using glue(adhesives) more and more to hold their main structures together!
Car and plane manufacturers wouldn't even sign off on the size axles on ebike hubmotors and they're steel, so the idea that it's ok to use an adhesive for such a small surface area that is effectively a motor mount is absurd. There have already been glued torque arm failures, some due to improper prep which is guaranteed a significant percentage of the time, and some with proper prep, and the excuse offered is that it must be fake DP420 instead of the obvious, that it's simply a bad idea.
Easing heavy weight on a glued connection is about as useful an experiment as the old Crazyglue commercials. Take a big hammer and beat on it while hanging some weight and watch what happens. That would be far closer to real world use.
How many of the epoxied torque arm advocates realize that the shear strength of DP420 is about half as strong when bonded to some steels? Did you know that it loses about 90% of its strength at only 82°C? The stated limit is 121°, but it has less than 5% of its strength at that point. As hot as some guys run their motors there's little doubt that their axles, which have a direct metal-to-metal connection with the stator, get above 80°C. A little research is warranted before following something that doesn't sound right.
I love using epoxies and taking shortcuts whenever I can, but not when it comes to dropouts and torque arms. The main reason there haven't been tons of failures is that the thick aluminum dropouts are quite strong, I'm sure a lot stronger than the DP420 in this application. If the axle is well fitted to the dropouts then the torque arm doesn't come into play unless the dropouts snap. Another reason is that those who use regen is still in the minority, and it's regen that's the real torture for dropouts and torque arms.