Yt decoy clicking noise

[Mlegere1]

Please help!

I have a 2021 Yt decoy core 3

I have been experiencing a very loud clicking noise while pedaling under load. Originally I took it to my local bike shop. They thought it was the motor (EP8) and they warrantied the motor through shimano. The noise came back after a couple rides. The weird thing is that the noise will typically start about 10 miles into a ride. It will typically be in the lower gears but then start to be heard in all gears. The drivetrain shifts perfectly and nothing looks bent. The chain is also not stretched. I’ve tighten all pivot bolts and everything else on the bike. I took it to YT to ask them about it. I live local to their US location and they have been awesome about trying to fix it. The only problem is that they are unable to recreate the noise as it typically only happens about 10 miles into a ride. After three times with YT’s mechanics the noise seemed to go away after they said they had “taken apart the V4L and made sure it was all good”. But again the sound is back. It’s a new motor and I have recently gotten brand new crankbrothers carbon wheels on it with new hub and new freehub body. I’m totally lost on what it might be. I’ll try to attach a video but I’m not sure exactly how to get videos on this post.

Decoy video

 

[Brett #174]

Really sounds like a drivetrain issue in the video, have you tried removing the little chain guide above the front sprocket? Mine used to catch on the chain constantly in certain gears, might be something to try and rule out to begin with.

 

[seamarsh]

That’s your drivetrain rear mech.. had mine do that.. I replaced rear mech, hanger and new chain, trying to chase the problem. In the end I think it was chain length although not 100%.. try to add or subtract a link and see if that helps… also make sure you are using shimano chain and get a new one to test. you should be able to recreate this behavior on the strand.. it you can’t I would imagine that means something is binding when it heats up.

try a new rear mech if chain doesn’t help.

oh and B tension has to be perfect on these.. so dial that in as well.. something to check when noise pops up is your B tension.

 

[Mikerb]

I would suggest the first place to start would be the chain. Split it and see if there are any stiff links.........or just renew it. Next step would be the chainwheel. Best guess as to why it seems only to occur 10+ miles into a ride ( or when the LBS has checked it out) would be that the chain....maybe chain to chainwheel interface.......is OK with a perfectly clean and well lubed chain.10 miles in it is no longer clean.

 

[seamarsh]

I would suggest the first place to start would be the chain. Split it and see if there are any stiff links.........or just renew it. Next step would be the chainwheel. Best guess as to why it seems only to occur 10+ miles into a ride ( or when the LBS has checked it out) would be that the chain....maybe chain to chainwheel interface.......is OK with a perfectly clean and well lubed chain.10 miles in it is no longer clean.

I replaced mine with a new chain and still had the issue.. but I was able to replicate on the stand, it was basically the chain skipping on the jockey wheels. so ended up replacing with another new chain and left it long, like 2 links longer, so long that there was a lot of slack in smallest cog.. I thought that is what solved it, but after a while I got tired of long chain and took a link (or 2?) out and was still fixed..

Could be a chain length manufacturing issue? idk it was a weird one. I never 100% figured it out.

Another thought was that I did buy these shimano chains on eBay when supply chain issues really bad, so maybe I got a knock off in the mix?..

Rear mechs are not too expensive so i would replace that as well! then you have a back up.. I also upgraded from SLX to XT.

 

[Mlegere1]

Thanks for all the replys. I will try these solutions. Yt is taking one last long look through everything. Should have the bike back tomorrow

 

[Mlegere1]

So after talking to a different local bike shop they brought up that they thought it could be that the Slx derailer had to much play and that the chain was getting caught up on the back of the cassette into the larger gears. I replaced the slx derailer with a new xt and so far no noise. Hoping the noise stays away.

 

[seamarsh]

Awesome, funny in my post I said I upgraded to xt, but I only upgraded to xt shift pod, could get xt rear mech mid pandemic. I think the self works but it's super sensitive to chain length like I detailed above.
Anyway glad it's working for you.

 

[Swingset]

All my issues with noise revolve around the splines on the Shimano crank. I get so many hard pedal/crank strikes it causes it to shift/loosen. If you re-install the cranks it settles back down. Just bought a set of 160mm for $55 and hope that reduces the problem.