StealthChesnut
Member
Over the past few months my Meta Power (29er, 2018) has developed a few noises. The most worrying was a creaking noise through the power part of the pedal stroke around 7-10mph, but this happened with motor off or in any mode.
The creak turned out to be EX1 cassette lockring wasn't tight. I found this thread on mtbr.com which goes into details:
forums.mtbr.com
In short, the EX-1 cassette is a solid piece for the lowest 5 gears, then 3 more pieces for the top 3. The large piece engages on the freehub only in one small area near the first (largest) 2 gears, so if the stack isn't held in place firmly by a properly torqued lockring then the whole cassette can pivot around the engagement point on the freehub. I was getting the creak worst in gears 4 and 5, which lines up with this as a cause. There was a little, but obvious, amount of play in the cassette so you may be able to check this without taking it off or at least by just dropping the wheel and giving the cassette a wobble.
While the torque wrench was out I'd also seen this post (thanks @Trickz !) suggesting the rear shock mount bolt can be noisy if not torqued. There was a fairly loud click/crack noise coming from somewhere, but that was hard to reproduce. The mount bolt has a range of 9-12nm - I set the wrench to 10nm and was able to snug it up a bit and again that noise has now gone.
Hope this is useful to someone!
The creak turned out to be EX1 cassette lockring wasn't tight. I found this thread on mtbr.com which goes into details:
Sram ex1 cassette noiseis
Hi, Hope this is not wrong forum to ask drivetrain question for eMtb. I am looking for experience with Sram Ex1 groupset. I have upgraded drivetrain on my eMtb to Ex1 by replacing all components except chainring (Bosch performance cx). Everything worked superbly for first 150 miles, after...
forums.mtbr.com
In short, the EX-1 cassette is a solid piece for the lowest 5 gears, then 3 more pieces for the top 3. The large piece engages on the freehub only in one small area near the first (largest) 2 gears, so if the stack isn't held in place firmly by a properly torqued lockring then the whole cassette can pivot around the engagement point on the freehub. I was getting the creak worst in gears 4 and 5, which lines up with this as a cause. There was a little, but obvious, amount of play in the cassette so you may be able to check this without taking it off or at least by just dropping the wheel and giving the cassette a wobble.
While the torque wrench was out I'd also seen this post (thanks @Trickz !) suggesting the rear shock mount bolt can be noisy if not torqued. There was a fairly loud click/crack noise coming from somewhere, but that was hard to reproduce. The mount bolt has a range of 9-12nm - I set the wrench to 10nm and was able to snug it up a bit and again that noise has now gone.
Hope this is useful to someone!
