SLX cassette toast at .5 chain stretch.

[Brianjonesphoto]

My chain just got to .5 On my Park go no go checker. I’ve been watching in closely for the last month or so. I put a new chain and rear pads on today. When I headed out to bed in the new pads the new chain is slipping under load on the upper 4 cogs of the cassette. Looks like I’ll ride the old chain to its bitter end at this point.

I tried my best to catch the chain wear early to avoid cassette replacement this time. How soon to you replace your chain?

 

[Astro66]

0.5. And after 3 chains change the hyperglide cassette and chain. I run the Deore 12s hyperglide cassette, which is only AUD$100 at my LBS. So it's not worth mucking around.

 

[RustyMTB]

Check your B screw tension before doing anything spendy. Shimnano drive trains are sensitive & a new chain changes the equation.

 

[Brianjonesphoto]

It’s a shimano cassette on sram drivetrain. One of the benefits of 11sp mix and match for best of both worlds.

 

[Bndit]

I had SLX drivetrain on Levo, when I sold it it had around 3800km`s and original cassette which was fine. Chain replaced everytime on 0.5% mark.

 

[RustyMTB]

It’s a shimano cassette on sram drivetrain. One of the benefits of 11sp mix and match for best of both worlds.

Doesn't make an difference. The interacting part are the chain, chainring & cassette. Your new chain is shorter than the old one by definition, so the two big variables are the wear on the cassette & the derailleur adjustment going out of true. You haven't said how many chains the bike's gone through, if it's three then you're into new cassette time anyway but if it's the first replacement, casette wear is unlikely, so check the b screw. SRAM make a special tool for this, no idea it it works with Shimano cassettes, the lbs will know.

 

[Mikerb]

My chain just got to .5 On my Park go no go checker. I’ve been watching in closely for the last month or so. I put a new chain and rear pads on today. When I headed out to bed in the new pads the new chain is slipping under load on the upper 4 cogs of the cassette. Looks like I’ll ride the old chain to its bitter end at this point.

I tried my best to catch the chain wear early to avoid cassette replacement this time. How soon to you replace your chain?

If by upper you mean the largest cogs you may be able to sort that without changing cassette. Re check your b tension and indexing. A new chain is stiffer than a used one ....ie less sideways flex and that impacts on how far the mech pushes it from one cog to the next. Possibly easing the b tension slightly will sort it.

 

[James_C]

I've tried and a part worn cassette never seems to take a new chain for me. Best to start with 2 chains from new and rotate them once a month.

 

[steve_sordy]

Cassette wear: new vs used pics.

If you zoom and compare the teeth, you can see several things:

# There are a lot of noticeable burrs on the teeth on the worn cassette. These can snag on the chain and it is less likely that you will get crisp instant shifting.​

# The burrs are a symptom of a huge amount of pressure on the tooth by the chain. The pressure has moved the metal of the tooth sideways to form the burr. Increase your cadence to reduce the pressure and extend cassette life.​

# Big burrs mean that the tooth face is no longer the shape that it was, because material has been taken away to form the burrs.​

# Because the tooth face is different, the round chain roller no longer sits nicely into the tooth hollow. The roller is supposed to just sit there and not move as the cassette rotates. The pin on the chain rolls inside the roller, which is why the oil needs to be in there and not on the outside of the roller. The roller starts to slide up and down the tooth instead.​

# As the roller slides it adds to the wear on the face of the tooth and further hollows it out. Eventually, the tooth can end up very pointed and hooked, hence the term "shark finning".​

# Don't confuse a tooth that is meant to be pointed with one that has been worn such that it looks pointed. If you look at the new cassette you will see on the same ring pointed and square topped teeth. This is a feature of the design to get smooth shifting.​

# Shark fins are another clear sign of a worn cassette. None on the example above.​

# A tooth that is pointed through wear will almost always have shark finning.​

​

This pic shows shark finning and burrs.
The old gear is in the front. Compare the tooth profile with the new one behind it. Is that shark finning or what! No pointed teeth though, even when as worn as this. But this is a single front ring, so not designed for shifting, hence no pointed teeth to start with.
I did try filing the burrs off, but the tooth profile was so worn that it didn't improve matters much at all.

Here is another front ring that is so worn that I'm surprised it worked at all. It didn't once I put a new chain on it! The chain worked fine on the workstand, but as soon as any pressure was put on it - off it came! I would have put the old chain back on, but by this time I was 80 miles from home and was fortunate enough to be able to find a replacement ring at the local bikeshop and fit it in the car park. For the avoidance of doubt the new one is at the back. Can you see the missing tooth? (err, I mean the gap where it should have been).

 

[fasterjason]

I've tried and a part worn cassette never seems to take a new chain for me. Best to start with 2 chains from new and rotate them once a month.

Absolutely correct, I have been promoting this idea at the shop for the last 20+ years. Keep the spare in a plastic bag and you have a fresh lubed chain ready to go, clean the dirty one when you have time.