Brand New Trek Clicks when Pedaling Hard

[Falconbal]

I have a Trek Domane AL 2 Disc, It’s brand new. When pedaling down on my right foot on the hardest gear, the bike will click. However, if I shift 3 times to an easier gear, it won’t click anymore.

I have tried a different Trek Domane AL 2 disc from a different store location (same store company) and that bike also clicks on the hardest gear.

I asked the store to make some adjustments, but they didn’t solve the problem. Any suggestions?

[ReapThaWhirlwind]

It's clicking like the chain jumping?

This is from wrong tension on the rear derailleur cable and/or from poor adjustment of the b-screw.

To fix this, you'll need to shift all the way into the highest gear. Undo the cable. Check the barrel adjusters. Dial them in all the way. You don't want any pretension on the cable. Screw the adjuster in until it's all removed. Pull the cable tight and re-fasten it into the rear derailleur. From here, check the high limit screw. Screw it out all the way, then screw it in until the chain is centered with the cog and with the rear pulley. If you look inside, the right amount is just a little more than when the screw makes contact with the hammer. This should give you a crisp shift into the second and back.

As you ascend up the gears, look to adjust the b-screw and adjust it based on how smoothly it allows you to ascend into the larger cogs. Typically, it's suggested to unscrew the b-limit as much as possible, but I've found in experience that prime shifting can involve some compromise on this. It does want to be unscrewed as much as possible, but not so much that it causes the chain (possibly) to loosen from the cogs. The chain wants to hug the cogs nicely. The perfect fit will enable a smooth to and from the largest cogs, with no skipping of the chain on the cogs.

If all this fails, consider that the pins inside the rear derailleur are worn, and the entire unit is past its service. There's no solid fix for this. Even lubricating everyday will only produce trivial performance boost compared to replacing the entire unit.

In some extreme cases, the chainline could be to blame, but there's strict emphasis on the term "extreme" there. Chainline is mostly subjective, and simply determines where in which the chain will run in a straight line. The subjective part is that certain gears are more favorable for certain riders, so that's where they want their chainline. It will not affect the shifting if all the parts are new, within their service, and configured properly. A chainline really has to be perverse to affect shifting, just so you know to check if need be.

[Nicholas]

Welcome to BikeRide, @Falconbal !
We recently received a few replies from our community members via Facebook:

Steve: If the clicking is coming from the rear mech then the H limit screw probably needs adjusting. Put the chain in the highest gear (smallest rear cog and big chain ring, as the picture shows). Uncrew it half a turn. If the noise is louder then screw it in a full turn. Keep adjusting by a quarter turn until the noise goes away. If the noise is the front mech then it’s the same process with the front mech H screw.

Karl T: On my Specialized, it was the pins of the chain clicking on the front derailleur chain guide. I put like 4 layers of electical tape on the backside of it, towards the frame and tire, not where the chain runs through. I did that only to determine if there was difference in the sound being made. There was. It was my issue. I had to tweak the chain guide so the pins wouldn't hit it.

Chuck: One of the BB cups isn't fully tight. And retorted the cranks for good measure.

Karl B: I've had something similar, fixed by partly unscrewing the pedal and putting some lubricant on the thread then tightening back up.

Simon: Where is the clicking coming from ? Could just be that the rear mech needs a small adjustment.

[Jesper]

(01-30-2022, 08:29 PM)Falconbal Wrote:  I have a Trek Domane AL 2 Disc, It’s brand new. When pedaling down on my right foot on the hardest gear, the bike will click. However, if I shift 3 times to an easier gear, it won’t click anymore.

I have tried a different Trek Domane AL 2 disc from a different store location (same store company) and that bike also clicks on the hardest gear.

I asked the store to make some adjustments, but they didn’t solve the problem. Any suggestions?

This might be a manufacturing defect issue if the exact same problem occurs on 2 of the same models.
2 problems here: 1) why can't the shop fix the problem? 2) when they could not fix the problem; why did they not replace the "brand new" bike.
These problems should be easily resolved; fix it or replace!
Demand (nicely!) that they take care of this. They were happy to take your money so they should be happy to solve your problem. This is not a good recommendation for buying a Trek and/or using that component group if these problems are prevalent. Nor is it a high recommendation to buy or service a bike at the shop.