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Discussion Starter · #1 ·
My drivetrain feels like it skips under load and I can't figure out why. Tuned the gears, which are shifting fine, lubed up everything but as soon as I'm uphill or have any high pressure on the pedals, it feels like something is skipping.

I'm using a shimano XT derailleur, shimano 9 speed chain, and a new shimano XT cassette.

Here is a slow motion video of the derailleur, and cassette going uphill:

Is there anyone who can tell what is going on from this?

Thank you
 

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I couldn't see skip, just a reluctance to change smoothly.
Initially it looked like the derailleur was just poorly adjusted, but you might need to look further, as it wasn't shifting to the higher gears even though the cable looked under-tensioned (could have been the camera angle though).
If the cassette is new, I'm assuming the chain is new too

Check the cables - you'll have to disconnect the inner from the derailleur first, but slide the outer bits up and down on the inner and see if there is friction. They should glide easily.
The hanger also needs to be checked for straightness.
And then make sure the derailleur high limit screw is accurate, then look at cable tension.
 

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Discussion Starter · #4 ·
So I re-adjusted it from scratch. I guess it's more of a grinding feeling than skipping.
In a way it feels like a broken bearing but the bottom bracket seems to move smoothly by itself.

I wonder if it's chain related.
 

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Discussion Starter · #5 ·
I didn't replace the chain because it doesn't seem to have any issues. Is that something that needs to be replaced with a new cassette? I replaced the cassette because I got new wheels and the old cassette was a boat anchor.
 

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The grinding is probably the chain being forced to original length on the cassette, then 'restretching' as it leaves the new cogs. If you want the most life out of a cassette, you 100% want to start its life with a new chain.
 

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My drivetrain feels like it skips under load and I can't figure out why. Tuned the gears, which are shifting fine, lubed up everything but as soon as I'm uphill or have any high pressure on the pedals, it feels like something is skipping.

I'm using a shimano XT derailleur, shimano 9 speed chain, and a new shimano XT cassette.

Here is a slow motion video of the derailleur, and cassette going uphill:

Is there anyone who can tell what is going on from this?

Thank you
When does the skip happens? I didn't notice it...
 

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Discussion Starter · #8 ·
I wasn't sure what to look for. But you are right, it doesn't skip like I thought. Replaced the chain and now the grinding which in my mind was sort of a skip is gone. The old chain had stretched almost a full link. While troubleshooting, I noticed one of my front chainrings had a bent tooth, which I tried to straighten and broke it. So now I have nice smooth motion on all but the center chain ring, which I have to replace.

Should I replace the other chainrings also? They seem fine but they have wear from the old chain so I'm not sure what to do.
 

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I didn't replace the chain because it doesn't seem to have any issues. Is that something that needs to be replaced with a new cassette? I replaced the cassette because I got new wheels and the old cassette was a boat anchor.
need a new chain.. chain rings may or may not be needed.. If the chain is skipping on the cassette badly, you've probably worn the rings heavily as well and will most likely need to replace them as well, at least the main used one if you don't shift the front much.
 

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I experienced chain skip while hard pedalling on the lowest gear. After changing the jockey wheels on my 1y+ derailleur, my problem is solved. My old jockey wheels looked like the middle one and I replaced with new one on the left.
 

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Discussion Starter · #12 ·
So replacing the chain fixed the bad grinding during hard pedaling but I replaced the middle and large chain rings also since the big one looked like shark fins and the middle was bent.

In addition shifting wasn't as smooth as I liked it and I thought the worn looking bottom pulley had something to do with it.

After disassembling the derailleur, I found that the top pulley had shot bearings, despite not looking worn. Replacing them with aluminum sealed bearings made the drivetrain shift perfectly. And they look really cool too since I got the red.

Thanks everyone for your help.
 
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