Cassette advice please

[Blackers]

Hi , I've just finished my p7 build a few days ago and my main niggle
With it is 7th gear on the rear cassette jumps under load .
I've fiddled with the adjustments on the rear mech to make it positioned correctly.
It's fine in all the other gears and a joy to ride .

The 2 possible causes are
Rear cassette needs replacement ? or
I put a z8 chain instead of z7 but all the other gears work as they should .

Builder error ? Or cassette? Or maybe chain needs a link removed ? :facepalm:
If cassette what's a good new replacement ?

 

[Captain Stupido]

Re:

Yeah, likely a new cassette required.

Just had the same issue on my (8 speed) C16R rebuild. It can be hard to tell how much life is left in an old cassette until you actually ride it - often they're OK with an old chain but skip once the chain is replaced. I usually replace on a rebuild but this time I was being a tight wad so thought I'd try the old one. Predictably enough it's no good.

If you're able to measure the old chain for wear before replacing you can usually judge whether the cassette is worth keeping.

IME they are often worn worse on the smaller cogs... mine skips under heavy load on the 2 smallest but it's fine elsewhere.

Re replacement - I've bought a new Shimano HG41 but not fitted it yet. Sunrace cassettes are fine too IMO, I'd just buy on price / availability and gearing.

 

[mk one]

By 7th you do mean the smallest cog right? from what i can see the teeth do look worn, though the chain does look long also to me.

 

[Blackers]

Re: Re:

Yeah, likely a new cassette required.

Just had the same issue on my (8 speed) C16R rebuild. It can be hard to tell how much life is left in an old cassette until you actually ride it - often they're OK with an old chain but skip once the chain is replaced. I usually replace on a rebuild but this time I was being a tight wad so thought I'd try the old one. Predictably enough it's no good.

If you're able to measure the old chain for wear before replacing you can usually judge whether the cassette is worth keeping.

IME they are often worn worse on the smaller cogs... mine skips under heavy load on the 2 smallest but it's fine elsewhere.

Re replacement - I've bought a new Shimano HG41 but not fitted it yet. Sunrace cassettes are fine too IMO, I'd just buy on price / availability and gearing.

Thankyou for you response

 

[Blackers]

By 7th you do mean the smallest cog right? from what i can see the teeth do look worn, though the chain does look long also to me.[/quote


Hi thankyou yes the smallest cog on rhs

I did take 4 links out of the chain . Think I'll take another 1 or 2 out maybe as the rear mech looks slightly scrunched up when on the small rear cog

 

[FluffyChicken]

Take a picture of it in big-big and then middle-small.
Big-big should be just doable and middle -small should be ok.
small-small can be hit and miss, but I would think just ok on normal 7 speed setup with the big cage mech.

but loose chain, poor jockey wheels, cassette, chains etc and bent mech-hanger or ...

 

[Blackers]

Take a picture of it in big-big and then middle-small.
Big-big should be just doable and middle -small should be ok.
small-small can be hit and miss, but I would think just ok on normal 7 speed setup with the big cage mech.

but loose chain, poor jockey wheels, cassette, chains etc and bent mech-hanger or ...

Thanks I'll take pics in morning.
I suspect the chain maybe slightly long still and rear mech isn't able to apply enough tension to the chain on the small cog ..
I'll try a couple of links less and see if that cures it .
If not I'll get a new cassette.
I'll update progress tomorrow .

 

[ishaw]

Re:

I had an issue like this and it turned out to be the lock ring. It was for a 12t small cog, not 11t so was just that little bit bigger and stopped the chain sitting right.

Other than that, wear and the usual suspects have been covered by others.

 

[Blackers]

Re: Re:

I had an issue like this and it turned out to be the lock ring. It was for a 12t small cog, not 11t so was just that little bit bigger and stopped the chain sitting right.

Other than that, wear and the usual suspects have been covered by others.

Thankyou, I think you did well to spot that one tbh
A great bunch on here , very helpful

 

[Blackers]

Pics are as it was .
I've now removed 2 more links and it's still like a Jack in the box on the small cog so I'll be getting a new cassette as the small cog looks a bit worn And try that next .
Are the hg41 any good ?