Troul 

Having some intermittent ghost shifts with a shimano HG31 8sp cass.
Only will happen under power load, such as climbing an incline or elevated cadence using the 11, 13, 15, & sometimes 17 range.
Swapped the wheel set out with a backup assembly that identical for part numbers being used, & it does not happen at all.
I see some knurls happening to all teeth, but why it doesn't ghost shift when using the other ranges has me wondering what is going on. Maybe someone on here will see something that I am missing?
Less than 100 miles on this problem child cass. I’d hate to have this occur on the current backup one. I have some days off coming & would like to do some traveling on the bike!

The focus would not clearly capture the headon picture, if it's needed lmk & i'll try it again.

wesmamyke

Is the chain new as well or old? Old chain and new cassette will quickly drive you crazy with weird issues.

I had some odd problems with a HG-41 cassette I think it was. Not ghost shifting but the chain rubbing what seemed like the cogs next to it despite being adjusted properly. Had way better luck with the HG-51, but also found a chain that worked better on the 41 after some trial and error.

Troul 

Im not too knowledgeable with hg compatibility. Id like to move to a cassette that gives a better selection for highway use. Used to have a 34t & it was not good for my use. The 30t gave me that 11t which works nice, but it could be better imo.

yes its a new chain & rd is fairly new. Crank might have 100 miles on it.

alcjphil

An old chain on a new cassette will almost always result in a problem like this. Change the chain

Troul 

its a new chain

Troul 

happens with new chain

70sSanO

Bike Gremlin

A bit of (educated) guessing:

RD needs some fine tuning/adjustment on the barrel - the fact that it works fine with a new wheel leads to that conclusion: old wheel might have the cassette moved by a fracion of a mm to the outside, or inside, compared to the new wheel.
If the chain is new, the cassette on the new wheel could be worn, or at least the few mostly used sprockets (have they been run with an older, worn chain?).
RD hanger is misaligned.
Shifter cables and/or housing needs replacemant, better routing or both.

Troul 

to make sure it's understood, when I say "...part numbers being used" I am saying the backup wheel is using the same part numbers across its makeup as the problem child is also using.
Nothing is worn to a point of imbalance, irregular, nor favored in use.

Defective cassette is all I am suspecting, just not seeing the defective zones is my concern that I was hoping someone else could see.
The cassette is going back to the retailer for warranty. Unfortunately I dont get compensated for my labor time for the RR-setup. Glad I didn't have to pay for that service!

Bike Gremlin

Cassette wear is hard to tell, unless it is severe (way past the point when a new chain would start skipping).
Each user (99% at least) has sporckets they use significantly more than the others - it's a normal thing, as far as the word normal goes. In addition to that, smaller sprockets tend to wear faster (fewer teeth, plus more revolutions per one crank revolution).
Cassette could be bad, though, of course.

Troul 

Those smaller gears are def less used compared to the larger dia ones. Even though I do try to run each one equally, to make it nondiscriminatory as so they dont get all cranky & file an EEO.

For the time being, I'll warranty it out & cross the fingers not the chain!

dsaul

I seriously doubt the cassette is defective. There usually some difference in alignment from wheel to wheel that is due to manufacturing tolerances. Even using the same exact cassette, you may need to tweak the derailleur adjustment to get proper shifting performance between two different wheels. You can usually use thin spacers to get two wheels to be interchangeable without messing with the derailleur.

If it is ghost shifting, that means the derailleur is biased toward the next larger gear and the chain is probably rubbing on that gear. On the smaller cogs, the the teeth can pick up the side plates of the chain and cause the ghost shift. On the larger gears(with more of a jump between tooth counts), the teeth may not contact the side plates and won't cause the ghost shifting.

Troul 

the odd thing is it just started to do this. It has been fine from day one after dialing it in to the RD up until the day of creating this thread.

Troul 

Replacement came in. Will give it a try tomorrow. It's installed & ready to rock. Cant wait!

Bike Gremlin

Waiting to hear if it works. Fingers crossed.

Troul 

Seamlessly functions like the backup wheel assembly. Didn't even attune any of the trim settings.