I'd like to improve reliability and have fewer problems with my drivetrain. What more can be done?
I have an electric bike. I only ever use the six smallest sprockets on the 12-speed cassette, even with the motor off/dead battery. The bike is regularly maintained by experienced mechanics at a bike shop. I clean and de-grease my chain, derailleur, and cassette regularly. I replace chains and cassettes at the recommended intervals with equal or better quality parts, and despite this I still occasionally have problems such as the above disaster photo from yesterday.
I have considered switching to a drivetrain with fewer speeds (costly as this means replacing numerous parts), maybe adding a chain catcher, anything else?
I've put 4000 miles on this bike since buying it new 15 months ago, and I aim to do at least 10000 miles before replacing it. I can't have the chain gouging the chainstay and/or getting stuck between the chainring and guard. What would you do, to make sure this never happens again?
(If this is not an equipment issue at all, and is a "you're doing it wrong" problem, I'm happy to receive constructive criticism...)
Comment updates - It's a mid-drive motor, no space for a larger chainring, and not working very hard at time of failure. The chain came off the crank & wedged between it and the guard (second time this has happened). It is a quick link in the photo, but I broke that trying to free the chain, so I could roll the bike back home. It was a KMC DLC 12 chain and I suspect it wasn't the original cause of failure.
Bike shop mechanic has now custom-made this chain guide and replaced the chain, cassette, and derailleur. Also removed more chain links to keep it tighter, with the understanding that I never use the largest 4 cassette sprockets which is fine with me.