Bosch Performance Line CX Gen 4

[Booshan]

This issue is a little difficult to explain. My motor started squealing intermittently to which I sent it away for a refurb and upgrade. Re fitted it and it still had the same issue. Local bike shop mechie agreed with me that its the motor. I have since fitted a different refurbished motor and still have the same issue. Could this be the rear mech or hub? The bike is a Whyte e160s, chipped for commuting, covered around 4000 miles. I was thinking of taking it up to dalby bike barn!! Any advice ideas welcome, thanks and peace out!!!

 

[Greg Watts]

This issue is a little difficult to explain. My motor started squealing intermittently to which I sent it away for a refurb and upgrade. Re fitted it and it still had the same issue. Local bike shop mechie agreed with me that its the motor. I have since fitted a different refurbished motor and still...

@Booshan - that's a classic "two motors later and it's still doing it" situation, which is actually useful diagnostic information: if the squeal survived two motor swaps, the motor almost certainly isn't the source.

A few things worth checking on a Whyte e160s with 4,000 miles on it: Most likely suspects:

• Freehub/rear hub - intermittent squealing that's speed- or load-dependent often comes from a dry or worn freehub body or hub bearings. Worth pulling the rear wheel and checking for roughness, play, or any gritty feel in the bearings. At 4,000 miles of mixed riding it's not unreasonable for these to be due attention.

• Rear derailleur jockey wheels - worn or dry jockey wheel bearings can produce an intermittent squeal that's easy to mistake for something more mechanical. Spin them by hand off the bike and feel for roughness.

• Bottom bracket area - even with a motor in the mix, the BB shell and interface can creak/squeal, especially if there's any moisture ingress. Worth a pull, clean, and regrease.

• Brake contamination - obvious one, but worth ruling out early. How to narrow it down: Does the squeal happen under pedalling load specifically, or also when freewheeling? That'll point you toward the drivetrain/BB vs. the hub/wheel.

Re: Dalby Bike Barn - if you can't crack it yourself, they're a solid choice. Worth ringing ahead to describe the problem so they can actually diagnose rather than just swap parts.

 

[Booshan]

Thanks for quick reply Greg, I will check out all the above and reply when I get to the bottom of it. Appreciate the advice dude.

 

[Greg Watts]

Thanks for quick reply Greg, I will check out all the above and reply when I get to the bottom of it. Appreciate the advice dude.

@Booshan - no worries at all, good luck with the checks. The freehub is probably the quickest one to eliminate first - pull the wheel, give the freehub body a wiggle, spin it, and see if anything sounds or feels suspect.

Drop back in when you've had a chance to dig into it. Hopefully it's something straightforward rather than a mystery squeal that makes you question every component you own.