Papa said:
liveforphysics said:
Do you really think any e-bike appliction would ever need a stronger chain than simple #219??? How many belts have we seen skipping or broken or whatever else, and who has ever had #219 (or even #35) fail for anything? You and throw graphs and charts away, the motorsports world has done 50+ years of real-world testing, and the proof is inherent.
And speaking as a pro wrench, one of the biggest money-makers of the 70's and '80's was timing
chains - typically at 25k to 40k they had either wore-out or failed completely - and not from lack of lubrication or tire smokin' abuse either. I bought a '73 Civic and drive it 103,000, negligent miles on its original 'belt'. But examples aside, the original issue the OP raised was not one of reliability or longevity... but
noise. So what's your suggestion(s) to his dilemma?
Honda is an excellent example
They used belts for a few decades because they were silent. Right now, Honda doesn't use a belt for any engine (at least that I'm aware of). They moved to Honda silent chain with the advent of the F20C in the Honda S2000. Reason? Belts become/became pretty substantial reliability problems with monster cam lobes and stiff triple valve spring setups. Toda and other companies released various kevlar timing belts and things to relieve the problem, but things would still get pretty sloppy by around 5-10k miles of running on big lobes/springs.
After the move to silent chain (a chain with no rollers or contacting pins to click), folks get multi-hundred thousand miles and the chains are still like new. You can run as big of cam/spring combo as you like on the F and K-series engines and never worry about belts shredding or skipping teeth etc. You do need to change to a smarter chain-tensioner design though... I hate the Honda auto chain tensioner setup... But the chain/sprockets themselves are outstanding, extremely quiet, pretty fine pitched, and handle loads of RPM and power.
I put mine through 10,000rpm drive sprocket speeds dragging along some pretty brutal lobes against mean triple springs, and every time I tear into the engine, the chain looks brand new.