FurryOnTheInside
In Memoriam
There's no power running through the return side of the chain where the rear derailleur operates. Therefore I *expect* that even on MBs the failings of the derailleur systems are down to improper installation and maintenance, ie choosing cheap derailleurs (check the reviews on the ebike/MTB/etc forums), "chain suck" from worn chain and/or sprockets (you should expect to replace them very frequently), and overenthusiastic operation of the throttle. Impossible to prove that, though. I am going to try anyway (with a 66).
But one thing is certain, a narrow ie multi speed chain concentrates wear. Halve the chain's internal width and you halve it's lifetime. This may be acceptable for a relatively pathetic 66cc but maybe not with a 125cc that outputs a lot more than double the HP.
Is my thinking.
Is a dingle acceptable? Two single speed ratios, using the same total tooth count (for the same chain length) on two different lines, both lined up correctly, but you have to stop, release chain tension and move the chain manually between the high speed sprockets and the town/hills sprockets. It is (not popular but known) from fixie cycling.
I have been looking at it for the 66 but the sprocket cover /clutch lever mount dimensions cause real issues and limit the possible ratios and would require significant modifications. This may not be such a problem with the engine you're looking at. idk how the output sprocket looks on those but I think it would be worth checking out.
But one thing is certain, a narrow ie multi speed chain concentrates wear. Halve the chain's internal width and you halve it's lifetime. This may be acceptable for a relatively pathetic 66cc but maybe not with a 125cc that outputs a lot more than double the HP.
Is my thinking.
Is a dingle acceptable? Two single speed ratios, using the same total tooth count (for the same chain length) on two different lines, both lined up correctly, but you have to stop, release chain tension and move the chain manually between the high speed sprockets and the town/hills sprockets. It is (not popular but known) from fixie cycling.
I have been looking at it for the 66 but the sprocket cover /clutch lever mount dimensions cause real issues and limit the possible ratios and would require significant modifications. This may not be such a problem with the engine you're looking at. idk how the output sprocket looks on those but I think it would be worth checking out.