Noise from back of bike.

[dodgeman]

I know it’s tough to diagnose a noise over the internet but it’s worth a shot. Trek Verve +3, Bosch mid drive, 9 speed 3300 miles. I’ve been hearing it a couple of months. I put it on my repair stand and had my son with me since his hearing is better. We are pretty sure it’s not the tires or the motor. It only does it when pedaling and it’s definitively at the rear. It doesn’t do it at any particular location of the chain, pedal or wheels. It does it in all gears but changing gears sometimes makes it louder or quieter.

The sound when riding sounds like a click, almost like a rock in the tire. On the stand it sounds almost like it’s a little bit between gears, but I don’t think it is a gear adjustment problem but could be. It’s not a continuous noise but rhythmic. It stops the minute you stop pedaling. Any ideas? I may have to take a trip to the LBS, which isn’t so local.

 

[PCeBiker]

On the stand it sounds almost like it’s a little bit between gears, but I don’t think it is a gear adjustment problem but could be.

I just had a similar clicking noise and it was in need of a gear adjustment after my cable had stretched.

It should be quite simple to find out if it is your gear adjustment.
Just put the bike back on the stand and adjust your cable one way then the other to see if it affects the sound.

My cable adjustor has detents and clicks in every ¼ rotation.

Just count how far you turn the adjustor from where it is now, so that you can put it back to where it was if it has no effect on the noise.

If it is cable adjustment, the sound will get louder as you turn the adjustor one way then get quieter and disappear as you turn it the other way.

 

[PCeBiker]

It’s not a continuous noise but rhythmic. It stops the minute you stop pedaling.

The rhythmic sound could be from the chain contacting the different shaped and sized teeth on the sprockets that allow for smoother shifting between gears.

 

[Stefan Mikes]

It could even be a worn hub bearing. A visit to the shop maybe?

 

[dodgeman]

Thanks for the suggestions. I think I’ll mess with the shifter first.

 

[Stefan Mikes]

Dodgeman, the strange noise could come from anything. Not an easy cake to diagnose!

 

[PCeBiker]

Dodgeman, the strange noise could come from anything. Not an easy cake to diagnose!

It's easy to adjust the shifter cable to see if it eliminates the noise.
I've adjusted mine while I was riding the bike.

If it doesn't work then set it back to where it was and take it to the LBS.

 

[PedalUma]

How clean and well lubed is the chain? Could be sticky links. When was it replaced?

 

[dodgeman]

Original chain, I lube and clean every 100 miles. I also have a wear gauge and it’s still good.

 

[PedalUma]

Put the bike in a middle gear and flip it upside down. Look to see if the jockey wheel is perfectly vertically aligned with the cog. Adjust the barrel adjuster to align it. If that is the problem the noise will disappear.

 

[PCeBiker]

Put the bike in a middle gear and flip it upside down. Look to see if the jockey wheel is perfectly vertically aligned with the cog. Adjust the barrel adjuster to align it. If that is the problem the noise will disappear.

When my drive train was clattering, I only had to adjust the barrel screw to take up the slack in the cable.
I didn't need to mess with the limit screws.
They aren't affected by cable slack.

I adjusted my barrel screw at the shifter while I was riding my bike and stopped the clatter.
It took all of 30 seconds to fix.

 

[dodgeman]

Turns out it was a loose cassette and a couple of loose spokes. Fixed at my LBS for $34. The bad part is my LBS is an hour drive away.