I have a Cannondale Moterra that I bought lightly-used from a friend. It has the Bosch 750 Wh motor. Killer fun, this bike!
Drivetrain is an issue, though. From early-on, I got pedal-skipping under load. The kind of skipping that usually tells you that the freewheel, chain, or front sprocket is warn-out …only this happens after like 2-3 rides—on a completely new drivetrain. I’ve replaced everything: freewheel, chain, derailleur, front sprocket, but still, after only a few rides, the skip is back.
Shimano slx derailleur and freewheel, Shimano 12spd chain, fsa front sprocket. Anyone have any suggestions? I believe that the fsa front sprocket is the limiting factor here, since it’s either the only, or one of the only options for the Cannondale offset, and Bosch spindle. I really wish it could be all Shimano!
Derailleur hanger out of alignment?
—no. We’ve straightened it (to no effect).
I’m starting to wonder if the chain isn’t cut too short. And / or if shifting under load is twisting the chain.
You said you replaced the freewheel, but modern mountain bikes don't have a freewheel. Did you mean the cassette? Cassettes are the modern version of freewheels. Or perhaps you were referring to the freehub, which is the ratcheting assembly inside a rear hub that allows the cassette to "freewheel," i.e. spin freely while coasting.
Whatever you meant by "freewheel," the freehub or the cassette could both be causing skipping under load, so I would make sure you check out both of those systems. Sometimes freehubs can benefit by just being disassembled and cleaned.
Yes, cassette. You can see it’s relatively new in the photo (I’m not big on washing bikes, because: bearings).
I am old enough to have worn out freewheels as well as free hubs and cassettes, unfortunately, long and short: the skipping is just like a stretched chain, worn-out cassette, or even sprocket. Yet, they are all new.
I’ve had it in a few shops, to no avail. A free hub issue is an interesting idea, but why then, does everything work well for 3-4 rides after I replace the front chainring?
Could be the clutch in the mech is creating too much resistance and causing the chain to kick back. Try adjusting the clutch or having it off. Obvious one is gear cable could be badly routed/kinked check both inner and outer for tight spots by cycling the suspension without a shock. Other than that freehub internals would be most obvious thing - try a known good system such as a 18t dt hub or something.
Oh, b limit could be too far in and chain might not be wrapping around the smaller sprockets?
A friend had replaced everything on his 11 speed XT drivetrain, some parts twice, trying to fix noise and skipping in the middle cogs of the cassette. When he installed a HD (steel) freehub body the problem went away and has not come back. Apparently the independent cogs of the cassette had dug in to the alloy freehub body enough to cause misalignment. I would think an ebike would come with the steel freehub body though?
Hey all: I finally got somewhere on this problem. I swapped out the wheel that had the Shimano cassette / free hub / wheel for an i9 wheel that I have built to a sram drivetrain (on my enduro bike). Switched the derailleur and chain to sram too. 1 ride in, and it’s working fine! No skips! Gonna give her another ride today!
Thanks for the input. The comments here and help from LBS’s have me on the right track, I think.
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