Bosch Performance line drive system problem?

[Bob.ebiker]

Hi.

I have a Trek XM700+ with 4600 miles on it. A week ago I started to notice a subtle clicking or ticking noise coming from what sounds to be the Bosch drive unit.

At first I though this might be the pedals, as I have had pedals click when the bearings are going bad (cheap pedals). But the noise is not as well synced to the pedal position as I have experienced before.

I changed the pedals anyway. No improvement.

I have tried to quantify the noise: The clicking/tickling is there only when pedaling, regardless of how light or heavy the pedaling force. The noise is sometimes at the same pedal position for each pedal (for example when either pedal is a the bottom of the stroke). The noise mostly happens multiple times per pedal rotation, but not always. I can't say for sure that the noise is happening at the same rate of rotation of the motor drive unit output sprocket, but maybe. Lastly, the clicking/ticking seems to start after a mile of riding.

The chain is in good condition (wear/clean/lubrication wise).

I have read that some have had motor drive unit bearing problems if water gets inside, but I have never rode in the rain or had the bike get wet (since new).

I put the bike on a work stand and rotated the pedals and the drive unit seems ok, but from prior experience with bad bearings (from another hobby), have to wonder if there is a problem inside. I do wish the unit was quieter when I turned the pedals, but to not have anything to compare it to.

The bike is nearly 3 years old, so I don't see getting any warranty help, and do not know of any local bike shops that are truly qualified to help me with this (Austin Texas).

I have read threads on here and watched repair videos but am not sure that I have the classic bad bearing problem as they seem to depend on water ingress. Maybe I am just now getting to that point via another cause.

Any help appreciated.

 

[Ravi Kempaiah]

do not know of any local bike shops that are truly qualified to help me with this (Austin Texas).

Any TREK dealership would be able to help you. here is one such store:

Find a bike shop near you | Trek Retailers | Trek Bikes

www.trekbikes.com

 

[simonns]

Check the crank bolts. I had something similar and after I snugged those bolts up the noise went away.

 

[topcatken]

BOth my XMs get a sound like chain slap. Make sure the clutch is engaged, (found on the rear derailleur. Then I had the motor opened and found that the chain slaps against 2 tabs inside the motor housing. I put a little piece of electric tape on the tabs and the sound was good. It returns every few thousand miles and then I repeat. One of my XMs has 8600 miles.

 

[GuruUno]

Howz about that noise when letting off of the pedaling and then the drivetrain spins up and gives a "kick" with the click for a millisecond? Called Bosch e-bike support to as about the "damping film" and they said, "We've had customers who have had issues with clicking and other noises, go to the dealer to have them assist."
So, if you look at ALL of my previous postings here as well as on the Trek forum, how is it that the issue still happens? My point being 2020 Bosch products/motors are different; does this mean they acknowledge the previous generation was deficient and had issues, hence the new/improved model(s)?
Big buck investments to be beta testers, ya think?