Skipping gear under load

[filippimini]

Hi all,
I can’t get the shifting right on my 2015 Giant trance. The gears move up and down the cassette perfectly. However when riding in the 2nd and third smallest cogs the chain slips/skips meaning you can’t get the power down. The b tension was way out, but even with that adjusted to give 5-6mm between the gear and the jockey wheel it still skips. The chain wear is 0.5 on the indicator. The cassette doesn’t look too worn, but I’m no expert.
Any advice?

 

[moorey]

Many possible causes.
-cable needs changing
-bent hanger
-bent derailleur
-slightly bent cassette teeth.
-chain/cassette combo not playing well with wear
-full moon.

 

[bear the bear]

Replace the cassette and chain problem fixed.
Given its 2 cogs, it eliminates most of @moorey's list except full moon

 

[moorey]

Replace the cassette and chain problem fixed.
Given its 2 cogs, it eliminates most of @moorey's list except full moon

Disagree. The reduced spring tension in smaller gears will be more effected by a crappy cable.
A bent mech or hanger will totally effect gears 2&3 but not 1 if the limiting screw stops the 1 in the right spot.

 

[filippimini]

Thanks guys.
I might try and borrow/buy a derailleur allignment tool before I go and replace the cassette and chain. The derailleur doesn’t look right, but my eye sight isn’t exactly great. I think this is more likely as the bike has only developed the issue recently and hasn’t been ridden enough to warrant excessive wear.

 

[Cardy George]

Hold up @moorey, I'm reading that as gears 9 & 10 (or 11 &12) and @filippimini is saying it shifts fine. Sounds more like chain to me.

@filippimini how much is 'not enough' riding?

 

[bear the bear]

Thanks guys.
I might try and borrow/buy a derailleur allignment tool before I go and replace the cassette and chain. The derailleur doesn’t look right, but my eye sight isn’t exactly great. I think this is more likely as the bike has only developed the issue recently and hasn’t been ridden enough to warrant excessive wear.

Or take it to a shop to have it looked at?
An alignment tool whilst handy to have isn't cheap for a decent one

 

[Scotty675]

New bike time

 

[T-Rex]

Hi all,
I can’t get the shifting right on my 2015 Giant trance. The gears move up and down the cassette perfectly. However when riding in the 2nd and third smallest cogs the chain slips/skips meaning you can’t get the power down. The b tension was way out, but even with that adjusted to give 5-6mm between the gear and the jockey wheel it still skips. The chain wear is 0.5 on the indicator. The cassette doesn’t look too worn, but I’m no expert.
Any advice?

Speed link on upside down?

 

[moorey]

Hold up @moorey, I'm reading that as gears 9 & 10 (or 11 &12) and @filippimini is saying it shifts fine. Sounds more like chain to me.

@filippimini how much is 'not enough' riding?

Second and third smallest cogs...
I always eliminate the easiest and cheapest first. It is probably more than a crappy cable...but it MIGHT just be a crappy cable.

 

[filippimini]

Speed link on upside down?

Thanks for the idea. How do you tell? It doesn’t have any directional markings on it. The chain is a KMC 10S

 

[filippimini]

Or take it to a shop to have it looked at?
An alignment tool whilst handy to have isn't cheap for a decent one

I always like to learn. If I have the tool and know how to use it, then I save myself money in the future.

 

[Daniel Hale]

Thanks for the idea. How do you tell? It doesn’t have any directional markings on it. The chain is a KMC 10S

i don’t think kmc is directional, shimano is & some quick links are

 

[Live2DieTrying]

Is the chain skipping over the cassette, or is the freehub slipping? Clean out the pawls in the freehub and a light regrease and try again...

 

[Flow-Rider]

Is the chain skipping over the cassette, or is the freehub slipping? Clean out the pawls in the freehub and a light regrease and try again...

I would suspect that you would get it to slip on others gears on the cassette if it was the freehub, the last gears that it slips on are most like the gears that the chain has run on more often.

 

[T-Rex]

Thanks for the idea. How do you tell? It doesn’t have any directional markings on it. The chain is a KMC 10S

The side plates on the speed link would be curved. If you put it on upside down with the curve going the wrong way, it works fine in the easier gears but when you get to the hardest couple of gears the reversed curve of the side plates stops the chain from having a good engagement on the small number of teeth on the cassette, and it skips. Ask me how I know......

Anyway, this example of fuckwittery was on an Eagle 12sp chain, if your joining link has straight sides this would not be what's causing your problem.

 

[stirk]

There is two types I skipping I think.

Skipping directly over the cogs will be chain and or cassette wear.

Skipping as if the chain is trying to change gears could be hanger, indexing or cable issues.

 

[filippimini]

There is two types I skipping I think.

Skipping directly over the cogs will be chain and or cassette wear.

Skipping as if the chain is trying to change gears could be hanger, indexing or cable issues.

Seems like it’s skipping trying to change gears. Cable seems good (only 6 months old). My bet is on hanger.

 

[moorey]

Seems like it’s skipping trying to change gears. Cable seems good (only 6 months old). My bet is on hanger.

6 months can be a long time, depending on conditions. Or if it’s bending in too tight an arc somewhere. Or if you have guide clamps or even cable ties too tight.

 

[T-Rex]

Seems like it’s skipping trying to change gears. Cable seems good (only 6 months old). My bet is on hanger.

A kink in the cable inside the housing could be causing this. In the hardest gears the derailleur spring has the least tension to position the derailleur correctly, which means it's harder to overcome the extra drag caused by a kink.

Disconnect the cable from the derailleur and see how easily it slides in the housing.