Small ring slipping on chain

[weaponsgrade]

When I shift from the big to the small ring, every now and then, the small ring seems to slip on the chain before engaging. I suppose I'll go ahead and replace the chain (chain has about 1000 miles). Other than the chain and ring, is there anything else I should look at? What's the explanation for the slipping?

[Peter P.]

Your small chainring is toast. You can't tell visually, but for me, when I have that downshift problem, it's the litmus test that it's time to replace the chainrings.

[John M]

Assuming, FD is correctly adjusted, I agree with Peter P. Sounds like an inner chainring needs replacement. Only other thing would be that if you are using a very narrow chain such as a 10s in an 8s drivetrain, the distance between the chainrings may be wide enough that the narrow chain hangs up. Most of the time combination still works fine, so that would be less likely.

[NateM]

if you mean that the chain slips on top of the ring before engaging, I call it skating,its probably more a problem due to front der adjustment. The chain isnt being dropped far enough inboard to engage the small ring,instead it skates on top for a moment. Try adjusting the der so that it moves farther in.Sometimes even angling it a bit helps.Of course if the ring is worn to a nub replace it.

[Dan Le foot]

Could be a too tight FD cable. Or inner limit screw needs adjusting.
I would take it to the LBS. I'm sure they could tell you in less than 30 seconds. I bet they wouldn't charge you.
Good luck.
Dan

[dave thompson]

A similar 'event' often takes place when using 10-speed components and chainrings that are "9/10 speed compatible"

[dvs cycles]

if you mean that the chain slips on top of the ring before engaging, I call it skating,its probably more a problem due to front der adjustment. The chain isnt being dropped far enough inboard to engage the small ring,instead it skates on top for a moment. Try adjusting the der so that it moves farther in.Sometimes even angling it a bit helps.Of course if the ring is worn to a nub replace it.
:beer: I had the same thing happen on a new group once. Simple stop adjustment was all it needed. :beer:

[jtferraro]

A similar 'event' often takes place when using 10-speed components and chainrings that are "9/10 speed compatible"

+1
I had this exact problem running a DA7800 10spd chain w/a SRAM Rival crank & Specialties TA '9/10' speed chainrings. Solution wasn't just replacing the chain - I had to also replace the inner chainring to the stock SRAM Rival (10spd specific).

Of course, you also want to make sure the small ring is correctly mounted (not 'flipped').

[weaponsgrade]

I measured the old chain and discovered that it was about 1/16" stretched or worn. I wasn't expecting that much wear. I went ahead and replaced it. My setup is Campy 10spd rings, KMC 10spd chain, and Force FD. I did about 45 miles today and so far so good.