Canyon Hybrid crank lurches forward at low speeds

[Esankey11]

Hello,

I have a six month-old Canyon Roadlite Hybrid bike. It has Shimano 105 R7000 front and rear derailleurs, a Shimano pressfit bottom bracket, and 105 hydraulic disc brakes.

I have noticed that the crank sometimes lurches forward suddenly while I am pedalling. The lurch is accompanied by a "clunk" noise. This happens about once a week (I ride everyday) and it only happens at low speeds. I recently took the bike to local bike shop for a routine tuneup and that did not seem to solve the problem.

I'd appreciate some help with this problem. I really love my new bike and I don't want to have to tolerate this.

Thank you!

 

[C R]

Hello,

I have a six month-old Canyon Roadlite Hybrid bike. It has Shimano 105 R7000 front and rear derailleurs, a Shimano pressfit bottom bracket, and 105 hydraulic disc brakes.

I have noticed that the crank sometimes lurches forward suddenly while I am pedalling. The lurch is accompanied by a "clunk" noise. This happens about once a week (I ride everyday) and it only happens at low speeds. I recently took the bike to local bike shop for a routine tuneup and that did not seem to solve the problem.

I'd appreciate some help with this problem. I really love my new bike and I don't want to have to tolerate this.

Thank you!

When you say that the crank lurches forward, you mean as if suddenly you had shifted to a lower gear?

 

[Cycleops]

Could be a false shift or the chain slipping on the chainwheel but should be sorted out by your LBS who can adjust it out.

 

[Sharky]

Could be a stiff chain link?
Could be the freehub not engaging initially?

 

[PaulSB]

Hello,

I have a six month-old Canyon Roadlite Hybrid bike. It has Shimano 105 R7000 front and rear derailleurs, a Shimano pressfit bottom bracket, and 105 hydraulic disc brakes.

I have noticed that the crank sometimes lurches forward suddenly while I am pedalling. The lurch is accompanied by a "clunk" noise. This happens about once a week (I ride everyday) and it only happens at low speeds. I recently took the bike to local bike shop for a routine tuneup and that did not seem to solve the problem.

I'd appreciate some help with this problem. I really love my new bike and I don't want to have to tolerate this.

Thank you!

Did you explain the specific problem to the LBS? If not the routine tune up will probably have been little more than checking brakes, cables, gears etc.

 

[Ajax Bay]

In the six months, how far do you think you've ridden?

 

[Esankey11]

Hello,

The lurch (about 45 degrees forward on the crank) feels more jarring than a normal gear shift and it sounds like snapping metal or something. I'm concerned it is damaging my bike.

I did mention this specific problem to the LBS before my tuneup and they said they would take a look. When the lockdowns are over I'll bring it back I guess.

I estimate that I have ridden 800 miles since I've had the bike.

Thanks.

 

[ianrauk]

Sounds like the free hub slipping to me

 

[C R]

lurch (about 45 degrees forward on the crank) feels more jarring than a normal gear shift and it sounds like snapping metal or something. I'm concerned it is damaging my bike.

That would correspond with you putting the most power, if the chain happened to jump between gears at the back I would expect a loud clang there. Why it happens is the question.

ETA, or as @ianrauk says, it could be the freehub, which if the bike was bought new it would be a warranty job.

 

[Cycleops]

Could indeed be the freehub. If one of the pawls is sticking that would explain the lurch until it hits the next one. As CR says it would be covered under warranty and involve replacing the rear wheel.

 

[Nigelnightmare]

Does it happen shortly after freewheeling?
If so it's another indication of the freehub slipping.

 

[Esankey11]

Does it happen shortly after freewheeling?
If so it's another indication of the freehub slipping.

Yes I think it happens most often when I start pedaling to accelerate after having already been coasting at low speeds. It never happens it high speeds.