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.

 

[Emteebee]

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?

As sayd, check b-gap. But.. Big chance the cassette is already too worn for a new chain. 0.5 is the absolute max, just a bit further and chain jumping guaranteed. If re-using a cassette is intended, replace chain at 0.3. Ride 2nd chain until 0.3 and replace for 3rd, but this is still not optimal.
Better: start off with 2 or 3 chains and rotate every x km, or based on their measured wear. This way, all chains will wear evenly and maintain a perfect fit to cassette and chainring.
At the moment I rotate 2 chains (XT and XX1) on SLX cassette and Raceface chainring. I rotate based on measured wear (when chain 1 is 0.02mm more worn, swap to chain 2 and vice versa). Plan is to wear all to the bone, replace all and then try a 3 chain rotation. Current setup is also a small experiment of comparing XT vs XX1 lifetime, and decide which one I'll take for next round of 3 chains based on cost/km.

 

[James_C]

I have 2 parallel nails on a wooden post, I hang both chains, compare the lengths, and put the shortest chain back on the bike . Its pretty easy to see which is longest.

 

[Brianjonesphoto]

I haven’t had a chance to circle back and check the B tension.

Reading through all the posts and suggestions I’m realizing maybe the best course of action into keep buying “cheap” slx cassettes and just ride the drivetrain into the ground. My mtb needs to be less maintenance than my dirtbike not more.

 

[Emteebee]

I haven’t had a chance to circle back and check the B tension.

Reading through all the posts and suggestions I’m realizing maybe the best course of action into keep buying “cheap” slx cassettes and just ride the drivetrain into the ground. My mtb needs to be less maintenance than my dirtbike not more.

What lubricant you use and how do you maintain?
If you're out for low cost with low maintenance, a drip wax (not oil based) might be worth looking into like Silca Super Secret or CeramicSpeed UFO drip. Keeps drivetrain nice and clean, no sticky greasy gunk piling up and easy to reset with boiling water. As long as you make sure you do a proper initial degrease, UFO drivetrain cleaner is super easy for this, just takes 1 treatment. Just re-drip after every 250-300km. Once every 1000-1200km reset the chain with boiling water and reapply a brand new layer. There's a lot of cash to be saved with a proper maintenance plan.
See this video for details:

 

[RustyMTB]

My mtb needs to be less maintenance than my dirtbike not more.

Think we've found the problem.

 

[Mikerb]

I always run a chain to 0.5 and have always made 2 chains work on the same cassette.........dont bother with a 3rd because I know it will likely slip ( all SRAM GX gear). As I suggested a bove you should not really expect a second chain to work perfectly without some readjustment of b tension and possibly cable tension.............after all it is (marginally) shorter and stiffer ( lateral) than the well broken in chain it replaced.

 

[Bndit]

I always run a chain to 0.5 and have always made 2 chains work on the same cassette.........dont bother with a 3rd because I know it will likely slip ( all SRAM GX gear). As I suggested a bove you should not really expect a second chain to work perfectly without some readjustment of b tension and possibly cable tension.............after all it is (marginally) shorter and stiffer ( lateral) than the well broken in chain it replaced.

How many km/miles you have got with GX chain? I have over 1500km`s and it`s still not at 0.5%… Was just thinking how many km`s the GX cassette will last…

 

[Brianjonesphoto]

Ok circling back to this topic. I finally had a chance to get back to working on my bike. Those who suggested B tension were Correct. I 3d printed a copy of the sram tool and my b tension was way off with the new chain. A quick ride showed no skipping after the adjustment.

Thank you for your help.

 

[Mikerb]

Good! To explain the b tension adjustment.......the b tension adjusts the distance between the upper/ guide jockey wheel and the cassette cogs. Firstly it ensures the guide wheel does not foul the largest cog/1st gear but secondly it determines the length of chain between the guide wheel and cogs all the way through the cassette to the highest gear/ smallest cog, becoming longer as it goes. A more flexible chain (ie broken in and/ or worn) needs that amount of free chain (the gap) to be smaller, whilst a new stiffer chain will work with a larger amount of free chain / gap.

 

[TheKaiser]

Ok circling back to this topic. I finally had a chance to get back to working on my bike. Those who suggested B tension were Correct. I 3d printed a copy of the sram tool and my b tension was way off with the new chain. A quick ride showed no skipping after the adjustment.

Thank you for your help.

Glad to hear you found a solution to your immediate problem.

I will just echo what Emteebee said a few posts up about the potential for changes to cleaning and lubrication (switching to wax based) that will dramatically increase chain lifespan. He mentioned using drip wax, which is the most intuitive for people coming off oil, but I also wanted to add that, since you're very much in the mode of checking chain wear regularly, you might be a good candidate for doing what has become a sort of standard of using 3 chains in rotation, per cassette, and immersion (hot melt) waxing. I mention it as you're clearly interested in maximizing cassette lifespan, which is best done by rotating chains so everything is a close a match as possible in terms of wear rate. There is no reason you can't rotate 3 chains through the bike while using a drip wax, but to my mind if you are already taking the chain off frequently as part of the rotation cycle then it's no bother to do them as a batch in the hot melt wax. If you have never done so, check out the Zero Friction Cycling website to see chain lifespan tests with different lubes. It is pretty startling how much of a difference it makes!

I see you are in Seattle, so the caveat I will add is that hot melt wax may not be the best choice for truly wet (like pouring rain) conditions, as the lube intervals become burdensomely frequent, however using a drip wax as Emteebee mentioned or a combo of hot melt and then topping up with drip only after occasional wet rides can still be a good match, unless you are out there in the pouring rain all day long.

 

[CarolinaCrawler]

I immersion wax all out bike chains. I love it and will never go back. But if the chain get any sort of wet, it will rust. I have blown the chain out with the air compressor after getting wet and it still will slightly rust. I haven't found that the rust does any harm and most of it is gone by the end of the next ride, but it'll still be there.