Skipping bike chain when on smallest (hardest) cog.
 

I need your opinions and help.

my bike chain skips when Im on my smallest cog. But Im not having problems when I'm at other gears. I have already aligned and adjusted the high limit of the rear derailleur. Also, already adjusted the barrel adjuster of rear derailleur but still in vain. Also, This only happens when Im riding my bike. But when I just turn the crank using my hands, It never skips. NOTE: my cassette and chain are new! :(

Tho I'm not Peter Sagan I can't wind my 11 cog even during at sprint (I just use the 2nd and 3rd smallest cog during sprint), I'm OCD enough and bothered that it skips even tho I wont ever use it.

Appreciate all your opinions and help!

Perhaps this will help.


Calvin to the rescue. Love that guy.

-Shin

I thought about it some more and perhaps these will help too.



-Shin

How many speeds?
ISTR an 8 speed cassette I had where I had that problem. Apparently they used the same end cog for 8 and 9 speed with the 8 speed having a thin spacer added. Without the spacer, my chain skipped because there wasn't enough space between cogs for the chain to "drop in".

Far and away the most common cause of this issue is when an 11-X cassette is used to replace a 12-X cassette without also changing the lockring.

Standard lockrings made for 12t or more end sprockets have a diameter too large for use with 11t. The edge of the lockring keeps the chain from settling full depth on the teeth. If the chain isn't fully engaged to the bottom, it's running at a larger diameter, so the tooth to tooth pitch is larger and it'll climb over the top and skip.

So if you used to have a 12t end sprocket. either buy a new lockring made for 11t, or grind this one down so it only reaches to about 2mm shy of the roots of the teeth.

Mine is also 8 speed roadbike. :( maybe that's my situation also? What can you suggest that I can do? or I'll just leave it like that since I wont ever use it even during sprint finish. But that thought that it jumps just bothers me. :( haha

Mine are 8 speed road bike. :)

Thank you for these. I'll watch this later when I get home from work. :)

A tight link could cause skipping worse on the small sprocket than others.

Gently crank the cranks on the work stand or upside-down, and see if the derailleur hops at a certain spot, or run all the links of the chain between your fingers.

Poor adjustment of derailleur or limits?

You might have misunderstood my notation.

You said you were using a new 8 speed cassette with an 11t smallest sprocket, which I described as 11-X, or, for example 11-26 or 11-28, or 11-whatever.

If the original cassette started with 12t, ie. 12-26 or 12-whatever, and you're using the same locking, then that's your problem.

Thank you so much for clarifying your statement there, appreciate it! Now I get it. But the smallest cog of my previous cassette is 11t too.

Okay. will definitely try this one! :)

Also, This only happens when Im riding my bike. But when I just turn the crank using my hands, It never skips. :(

You can simply eyeball it and see if the spacing between the 2 smallest cogs equal the spacing of all the other cogs.

i've had the skipping on just the smallest sprocket happen when the ratchet in the freehub begins to fail... it get progressively worse, and it begins to happen on the next larger sprocket eventually, too... it happens mostly on Formula(or UNBRANDED, or hubs branded by the frame makers, too) freehubs...

is your freehub held to the hub body by an Allen bolt inside, or is it "riveted" in place by a swedged part of the hub? Swedged-together hubs are lower end units... and they can fail.

check the things mentioned by the others, then suspect your hub... chain skip is usually noisy when it happens... freehub ratchet skip is nearly silent.....until it suddenly decides to engage... the skipping starts out as just a bit, then gets worse and longer at the pedals.... eventually, it won't hardly engage at all, and larger gears experience the "skipping" thing...

is the freehub coming loose, by chance? check it. excess "wobble" from worn bearings can also cause skipping... look for side to side(end) play, or "rocking' of the freehub... a bit of rocking is normal... more than a millimeter is not.... end play should be nearly undetectable...

ONE more possibility... is the chain extremely close to the derailleur mount bolt, or the hanger? THAT can have the chain touching the hanger/bolt at times of high load, and that can cause chain skip!