Rail 9.7 Chain problems again

[Marsh]

Ok so got myself the 9.7 and first 2 weeks riding it only to work and back to get used to it before throwing it around trails. So 1 month in 2nd time on trails and i heard the chain jump then it snapped, i repaired it and took it down to trek to get them to have a look.
All was good apparently and they measured & checked chain links and the cassette . Left the shop and chain started to jump mainly on the highest gear (smallest sprocket) So basically i ended up changing the cassette cranks (i went shorter 165mm way to long) and chainring. So 2 weeks in maybe 4hrs on trails and coming back from work last night i was pushing hard and bang chain started slipping again. Has anyone had this problem?

 

[maynard]

Sounds like worn chain and cassette. If it's a new chain then worn cassette . It's pretty easy to destroy chains and cassettes changing gear in turbo . I know I did.

 

[Marsh]

cassette, chain and chainring only 2 weeks old and i also i lift pressure between gear changing.

 

[Stihldog]

Since the bike and parts are fairly new, there could be a number of things happening here. The high/low screws are likely correct and the “b” screw may need to be adjusted or checked …with a gauge.
Then the indexing may need to be adjusted. (Barrel adjustment). Shortly after first use(3-15 rides approximately), the shifter cable will “settle-in”, or there may be a restricted bend or pinch in the shifter cable as it passes through different areas of the bike until it reaches the derailer. The derailer or derailer hanger may be bent. Ensure the shifter cable operates smoothly and properly. Any number of steps may have been overlooked by a mechanic at the LBS.

It’s certainly not a nice feel or sound when the chain starts skipping but it could take a little investigation to find the issue.
Good luck
Ps; I’m probably missing something here too.

 

[Marsh]

Thank you for the advice, its re booked in at trek, hopefully it won’t take them long to find the problem.

 

[Stihldog]

Thank you for the advice, its re booked in at trek, hopefully it won’t take them long to find the problem.

Let us know what they found? I’m curious since your Rail is fairly new.

 

[Marsh]

Ok so this morning i put the bike up on the stand to inspect further, so like I said previously I got trek to replace the original cassette and upgraded chainring and cranks. Reason why I changed the cassette was due to chain jumping and it ruined some teeth on it crank and chainring was my personal choice (shorter cranks for more clearance. So after the inspection I noticed they did not replace the chain, the chain snapped on me originally and I repaired it so it has 2 chain links on it. Im actually disappointed as i was told that chain originally snapped due to it being siezed up so i guess that was BS. Still taking it in to hear what they have to say and get a refund or a chain. Not what I expected from Trek in poole.

 

[JP-NZ]

What chain and casette are you running? Sram?

 

[Marsh]

Original parts that came with the bike shimano slx cassette with the shimano 12 speed chain with the xtr shifter, shifter was my upgrade

 

[maynard]

The cassette would be worn probably. So new chain would skip . Need new cassette and chain

 

[Skoogydoo]

My rail 9.7 has been a nightmare w chainrings/chains. So disappointing

 

[Third-Reef]

I have a 2021 9.7 with over 1500 miles on it. i have cleaned and lubed my chain 3 times since new. i use the finish line dry lube. Every 500 miles whether it needs it or not . Mine still shifts great, I only need to adjust it once after a fairly aggressive OTB experience. Someone did a test with lubed VS cleaning but leaving the chain dry life tests and there was surprisingly little difference. I typical don't ride in mud, mostly dust and sand, so your mileage may vary.