DT Swiss star ratchet issues

Or the chain ring. It would be a pain buying a new chain/chainring/cassette to swap out but as a trial but even if they weren’t the issue you would say least then have spares for the inevitable replacement.

Have you checked all the teeth. I had a random slippage a year or so back that was caused by damage to a single tooth on the chain ring. Hit it on a tree and had caused a bur on the inner side. This caused the chain to sometimes not sit properly and then slip. 5s with a file sorted it.

+1 for checking your chainrings and cassette. I recently re-jigged a bunch of components from one bike/the cellar to another. First ride out the chain was skipping on every high grunt climb, which could easily be mistaken for freehub slip. Initially I thought, new chain/old cassette, but then realised that it was fine in the outer ring of a double, did the rest of the ride in the big ring and all was fine, apart from my legs.  The inner chainring was goosed. Fitted a new/old ring I’d bought on eBay and all was fine.

If you can, stick the wheel in another, known functioning okay bike, and see if the skipping goes. If it does, it’s more than likely your chainring and/or cassette, particularly if you’ve recently fitted a new chain.

Fwiw, I’ve never had a star ratchet DT Swiss freehub slip on me over lots of bikes and loads of kms.

Pretty sure I have some near new 18t rings if you want to try some new ones.

Just one to check…. Do you take your rear wheel off to transport the bike? Ive had numerous customers with trashed freehubs/slipping ratchets over the years and the common factor has always been removing wheels regularly for transport. Its possible on DT hubs due to the fact the freehub is very loose and unsecured on the axle to have the freehub slip a bit outwards (or indeed the cassette fall off completely), but when you come to fit the hub there’s a step inside the end cap which means that you can tighten the axle up and it won’t remove the last couple of mm of play. That leaves your freehub free to move around a bit even though your axle is ‘tight’ – causing the issues you have.

If this sounds like you then make sure before you fit the wheel each time you ensure the end cap is fully seated. You cant rely on the axle tightening to do it for you.

Chain is somewhere in between 0.25 and 0.5 on the wear gauge.

cassette has a couple of tiny burs on some of the teeth but otherwise looks ok to my eye

edit: image upload from IOS/safari seems to be broken  will try something else

upload to https://postimages.org/  and link on here

I’m going to be the first to say 8-11 look battered, those were also the ones you indicated slipped.

That chain checker design is not the most accurate btw.

For me, the cassette wear looks more  uneven than mine. It is usual to get more wear in 6-11 but that looks quite aggressive to me. 1-7 and 11 + 12 look fairly fresh so I’m guessing most of your miles are in 8-10?? That focused wear is going to shorten the usual lifespan.

I’d be sticking a new drivetrain on. change everything …Chainring, cassette  and chain

Maybe a good case for a bigger front ring as well to shift the load up the cassette where there is more chain wrap.

Christ almighty. Not surprised that’s slipping.

Do we really think the wear on this is that bad? Looking into the teeth there doesn’t seem to be a great deal of wear even if most of the surface finish has been taken off the sides.

Unfortunately the only spare cassettes I have at the minute are microspline so not going to be cheap to try a fresh one out. Definitely would make sense to go for a larger front ring when I do though as the hills round this way aren’t exactly epic.

@benpinnick may be on to something though as the wheels do get taken off when the bike gets stored. Is this usually permanent damage to the hub/ratchet/freehub or is it just a case of needing to take a bit more care when putting the wheel back into the frame?

If you’re out of the saddle could it be frame flex or something?

I can never tell how worn a cassette is by looking tbh.

If it was the freehub at fault, I think it would be more likely in the lower gears as the 50t will put 5x the amount of torque through there as the 10t.

Blimey. I’d be installing a bigger chain ring too. Not much chain engagement in those smaller cogs and three of them look a bit haggard.

Frame flex could be part of it I guess. Not sure I can face swapping the frame out to try and fix it just yet though. 

You either have thighs of Oak, or that’s an E-bike. Either way, look at the shadowing on the rear faces of those smaller cog teeth. Where the chain is being pushed hard against them. Looks to me that the teeth are slightly flared, which is a sign that the cassette is borked. If you were able to use the larger cassette cogs (by using a bigger chain ring), the teeth would not wear so quickly, and there would be more engagement between the cogs and chain.

Also, that doesn’t look like a 12 speed chain checker. Use something like a Park CC4.

I don’t think frame flex is relevant. Just large force being placed on a few cog teeth.

Unless running a 10t oneup shark mini driver, I’ve never had a dtswiss freehub pull off the axle when off the bike without significant user intent. I guess if you hot swapped cassettes between wheels you could wear out the o-ring and reduce its efficacy but surely not from straight wheel out stuff.

However, the only time I’ve mashed any star ratchet teeth was due a loose rear axle under a fairly significant amount of torque. Rounded a few teeth and it would give up on enthusiastic pedalling.

Presumanly with a spotter, you could stand on the pedals in those smaller gears and watch if it’s the chain jumping or the cassette turning..

The LTJC-001 is compatible with all derailleur chains. For 9 and 10-speed chains, replace chain at or just before the 0.75% readings. For 11 and 12-speed chain, replace at or just before the 0.5% reading. Check with manufacturer for specific replacement instructions.

ZTTO MTB Bicycle Chain Wear Indicator Tool Links Checker Aluminum Alloy Road Bike Repair Accurate Tools

Seems that you want to blame everything else other than what you’re being told.

Even if you did have another issue the worn drive chain would make diagnosing harder. It’s the most obvious cause and the simplest thing to ‘fix’.

IMO you’d need some fairly drastic frame flex to cause skipping and would have other indicators like tyre rub on the stays. You’ve also clearly had the hub apart numerous times, would you have made the mistake of not fitting the end cap properly every time? Again I think you’d have other signs of this like the hub seeming slightly too wide when you went to put it into the frame. TBH I also am struggling to see how what Ben describes would occur (though he sees way more bikes than most us).

Do we really think the wear on this is that bad? Looking into the teeth there doesn’t seem to be a great deal of wear

Not on the bits that are left, but there’s a whole it of material gone. For me, it’s the shape gaps that’s tell tale. Look at the 24t cog in your first picture. Some of the gaps are symmetrical-ish and some are the shape of breaking waves. There are also some where the gaps are much wider than others. That’s very typical of heavy wear. The areas where the wear doesn’t look so bad are probably around the shift ramps that are profiled to handle the change of cog.

For 9 and 10-speed chains, replace chain at or just before the 0.75% readings. For 11 and 12-speed chain, replace at or just before the 0.5% reading

This is new news, I’ve had the numbers quoted for the 8/9 speed chains in mind and that anything less than 0.5 was fine.

Guess I’ll be off to buy some new bits then.

That cassette is gubbed. Particularly 12/14/16/18T

eBike by any chance?

Not an ebike.

So fitted a new SLX cassette and XT chain to replace the GX parts that were in there. Even factoring in the cost of a new (steel) micro spine free-hub it worked out about £55 cheaper than going for the SRAM parts. I also took some of the grease off the face of the star ratchet parts as they had gone very quiet and I suspect there was a bit too much in there.

First ride out and something skipped once, making quite a racket down by the rear hub. So a lot better than things were previously where I’d loose count of how many times it had skipped despite taking it easy most of the time but not perfect. Can’t decide if it’s worth chasing things further or just leaving it there. Will see how it goes after a few more rides I guess

Did you adjust rear mech indexing to take into account the sram > shimano change set up? No mention of changing front ring so is that still the old one and is the chain length correct.

Gear indexing checked/tweaked and seemingly running fine. Shifting is generally sounding and feeling much nicer/smoother with the shimano cassette and chain on there.

Same chainring.

Chain length set up as per SRAM user manual instructions rather than just matching to old chain.

f that doesn’t work it all goes in the bin and I have to buy a new bike.

Seems reasonable.