Home Forums Bike Forum DT Swiss star ratchet issues

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  • DT Swiss star ratchet issues
  • bigginge
    Full Member

    How long do people normally find the star ratchet in their DT Swiss rear hub last between replacements?

    Mine has recently started slipping again when I’m out of the saddle pushing in the higher gears (I am quite large at ~120 kg if that makes any difference). It’s starting to get really annoying now as I can’t really peddle on most of the fun trail sections now as the free hub just slips and I end up close to smashing my crotch into the top tube/stem or flying off over the bars

    The first time this happened a strip and re-grease sorted it out but I’ve tried this twice in rapid succession now and it’s still doing it.

    Have I killed the star ratchets?

    Are these really sensitive to the type of grease you use (I’ve not got any of the recommended DT Swiss freehub grease)?

    Do I need to find something stronger/stiffer to take my weight better?

    nixie
    Full Member

    How old are yours?

    Can you post a picture of the ratchets? It’s obvious when they are worn as the edges of the teeth get destroyed. Which version (18, 36, 54t) are you using?

    If you have to replace the ratchets you’ll get a tune if the grease with them.

    You might be a candidate for the new ratchet version https://www.dtswiss.com/en/wheels/wheels-technology/ratchet-deg-technology

    Fat-boy-fat
    Full Member

    Fellow large person. I find that star ratchets last years for me, as long as I maintain them and use the recommended grease. Once they’ve slipped, the damage is done and you need new ones. A strip and re-grease does buy you some time though. Another bit of learning, don’t go fir the high “tooth count” ones. Go basic. They last longer for big fellas.

    mert
    Free Member

    Have I killed the star ratchets?

    Probably, nothing likes slipping under load. Especially not repeatedly

    Are these really sensitive to the type of grease you use (I’ve not got any of the recommended DT Swiss freehub grease)?

    Not sure if the design has changed at all. But they used to be. I’ve got a pot of the DT Swiss stuff that i bought ~10 years ago, so haven’t tried with the wrong stuff lately!

    Do I need to find something stronger/stiffer to take my weight better?

    Stick a new set in, with the correct grease and see how it goes.

    clubby
    Full Member

    What tooth count do you have?
    The cheaper hubs tend to come with 18T ratchets but they are stronger than the 36T ones the posh ones use. It does sound d like you’ve stripped them. No idea what’s so special about the grease, but I’ve always used it as it came with the service kit and you don’t use much.

    intheborders
    Free Member

    I’ve got a near 20 year old one, works perfectly but TBH I’ve never greased it.

    Are you sure there’s not another problem, that is been masked?

    sillyoldman
    Full Member

    The Deg variants are more about offering a higher POE without compromising durability. Shouldn’t be an issue for you with any version.

    DT specifically state that their special grease should be used, but due to being a tight bastard, I’ve used Finish Line Wet Lube on mine for over 20yrs.

    Early 240 EXP had faulty ratchets – got FOC replacements for mine.

    Is that what you have?

    devash
    Free Member

    Definitely get the “special” grease and keep on top of the servicing. I pop the freehub off once a year and clean and relube.

    bigginge
    Full Member

    Some extra context:

    I’ve got the 18T ratchets in a 350 boost hub.

    I’d guess the hub has done something like 1000-2000km of riding since the wheel was built. Most of those miles are probably in reasonably gentle conditions as my local trails don’t really have much in the way of mud and are quick to drain when it does rain.

    The skipping doesn’t happen in all gears which was the main thing that made me wonder if the ratchet is not entirely at fault. It doesn’t happen at all in the easier gears where logic says I can apply most torque to the freehub and it should be most likely to skip. It’s only when I’m in gears 8-12 where this happens and the higher the gear the more likely it is.

    Given the above I was wondering if the freehub may be flexing when I’m in the higher gears, and the force from the chain is acting further away from the bearings, causing the ratchets to bind and not engage properly.

    5
    sillyoldman
    Full Member

    Sounds more like chain/cassette wear as that’s more likely on smaller sprockets with less chain wrap.

    honourablegeorge
    Full Member

    sillyoldmanFull Member
    The Deg variants are more about offering a higher POE without compromising durability. Shouldn’t be an issue for you with any version.

    Fine in theory, but in reality, the 54 tooth version does not suit heavier riders all that well

    sillyoldman
    Full Member

    Not tried that one as I’m not that fussed about POE personally, but likely a fair point!

    He’s on 18T anyway, so should be fine for many many years.

    hatter
    Full Member

    I’m a very heavy rider (over 125KG) and run the 54t ratchets for both gravel and MTB with no issues.

    But then again, I do keep on top of maintenance and use the correct DT grease.

    The higher engagement ratchets are reliable but less tolerant of neglect, give em a clean and a grease a few times a year and they’re generally fine.

    Same applies to fast engaging pawl hubs TBH.

    The 18 tooth versions are basically as bombproof as hubs get.

    nixie
    Full Member

    In that case how old is the chain and cassette? Have you checked the chain wear level? Do you have a spare (new) chain and cassette you could fit to remove them from the equation.

    1
    mert
    Free Member

    Given the above I was wondering if the freehub may be flexing when I’m in the higher gears, and the force from the chain is acting further away from the bearings, causing the ratchets to bind and not engage properly.

    I do have a vague recollection of someone finding a bent axle giving similar symptoms.

    Aidy
    Free Member

    The 18T ones are pretty indestructible ime. Most reliable of all the freehub designs by far. I had one that was still going strong after probably 18 years.

    richwales
    Full Member

    Timely thread – I’ve stripped my 370 hub and found the axle had snapped. New axle and bearings are ordered. I’m struggling to find any “DT special grease” in stock anywhere. Any recommendations for an alternative?

    sl2000
    Full Member

    Other reasons for thinking this is chain slipping rather than ratchet:

    1. You’re slipping in higher gears. These put less torque through the ratchet than lower gears. Would expect ratchet slip to happen in lower gears.

    2. The distance ridden (1000-2000km) is chain wear distance not ratchet distance (which is much longer).

    nixie
    Full Member

    @richwales given you need parts anyway do the ratchet upgrade, it comes with the grease.

    2
    spacehopper
    Full Member

    the only time ive had issues with the ratchet slipping is when i used ‘normal’ grease instead of the DT swiss stuff..

    UK Stock of the grease isnt great unfortunatley.. i had to order my last couple of tubes from Germany..

    youll end up googling alternatives and discover a few places saying DT Swiss special grease is the same as molykote TP42.. then find it on ebay for sale in small tubs.. (its a sort of beige colour)

    i thought id found the cheaper easier version of special grease in TP42.. as it works ok in summer.. but come autumn/winter when the temperature dropped it seemed to thicken up in use in the hub and i experienced one or two slippages.. cleaned up and switched to special grease.. and everythings working as it should again.. and had no issues since..
    (had the same issue in a modern 240 exp hub with a 54t ratchet.. and an ancient specialized S-works hub (with DT Swiss internals) with an 18t ratchet.. and a 350 hub with a 36t.. so it was deffo the grease..)

    im fairly sure the DT Swiss stuff is based on the molykote TP42.. but it definitley got something else in it that helps in lower temps..

    jhpbk
    Free Member

    I’m sure you haven’t done this..

    But I have on occasion seen people put the springs back in the wrong way round, and that seems to cause similar issues.
    Also worth checking the springs haven’t bent and aren’t providing the correct amount of ‘push’ back.

    bigginge
    Full Member

    I’ve checked the chain and cassette and they look to be in good condition still, this was my first suspicion as to what was going wrong the 1st time it happened.

    Will see about getting some pictures of the ratchet parts and ponder how the get the axel out to check that against a straight edge.

    Otherwise sounds like having the proper grease is a good idea to remove that from the equation so I’ll see if I can track down a tub anywhere.

    honourablegeorge
    Full Member

    They can also slip and even stop working altogether if gunked up, I’ve taken DT wheels apart on the trail and fixed them b wiping down and lightly lubing with chain oil

    oceanskipper
    Full Member

    I’m always confused as to how much grease to put on. It says a very small amount but then the DT Swiss videos show it being lathered on with a brush. Definitely not my definition of a small amount.

    Northwind
    Full Member

    IME they’re basically immortal. Most of my DT hubs started out as ex1750 wheels so they’re knocking on 20 years old. I’ve got the official DT 36T upgrades in them all but all those parts are at least 10 years old. I’m not heavy, but there’s been times when I’ve been decently strong, and I did used to ride em basically all the time. They’ve all been properly bombproof reliable.

    Tbh I’m not sure any of the rider stuff makes much difference? for wear, it can only really be whether they’re locking up properly on drive or not. And that’s basically got to be weak or otherwise not working properly springs, something restricting the ratchet’s movement (which could include alignment) or something preventing full lockup. Too much dirt, too thick grease, worn out tired springs (not an issue I’ve ever seen). Just possibly a really heavy rider could flex the axle, especially if it’s got an unsupportive maxle in it, but I’d be surprised, they are stronk despite the design being older than 12mm axles.

    Re grease, I’ve never had the proper DT stuff, I use a tiny wee swipe of slick honey on the faces. It’s tempting to fill things with sticky waterproof grease but that’s the wrong thing here I reckon, that’ll keep the sliding parts moving but could prevent proper locking up. I think I’d rather use oil than a thick grease.

    The sealing is OK, it’s not brilliant, it should keep solids out but can let a little water or thin mud in over time. But inspection and cleaing is really easy, just pull the entire cassette off (the end cap can be very sticky, if the whole cassette won’t pull off, get some molegrips on the endcap and rock it off first).

    bigginge
    Full Member

    So I’ve given up trying to find any of the DT Swiss Special Grease in stock and have just ordered a small (cough, 1kg, cough) tub of Molykote TP-42 from eBay to see if that helps get rid of the slipping.

    Looking closely at the ratchet rings I can see some polishing on the outer edges of the teeth but in general they look to be in reasonable shape with no bits missing or badly worn. Not that I know what good/bad looks like in this context.

    IMG_2825

    IMG_2824

    hatter
    Full Member

    They look absolutely fine.

    Assuming the hub’s been assembled correctly then if it’s still slipping I’d look at the Cassette or other factors.

    nixie
    Full Member

    Look fine to me as well. All the worn ones I’ve seen have chipping on the outer corners.

    Northwind
    Full Member

    Yeah that;s just normal polishing.

    If you’re still haivng problems I’ll have some standard ratchets somewhere,not entirely sure where though :) But I don’t think it’s your issue.

    TroutWrestler
    Free Member

    I have 350 rear hub with a ratchet. I can hear what sounds like a pulsing in the freehub when I coast at higher speeds. Has anyone got any ideas as to why that may be?

    oceanskipper
    Full Member

    Mine all pulse like that. I think it’s centrifugal force, or some rotational force anyway, working against the spring and then the spring pushing back.

    nixie
    Full Member

    There was a quite entertaining big thread on it a few years back where the poster downgraded as their OCD could not cope with that noise.

    Northwind
    Full Member

    Like a quieter/louder thing? If so that’s pretty much just the noise they make. No idea why though.

    bruneep
    Full Member

    There was a quite entertaining big thread on it a few years back where the poster downgraded as their OCD could not cope with that noise.

    and I got a nice 54t ratchet and tub of grease out of it

    oceanskipper
    Full Member

    Just had one of mine apart for a fettle/regrease as it was getting slightly noisier. Still some evidence of pink grease knocking about so it’s all pretty well sealed in there. Bearings still super smooth. Cleaned and regreased with Special Grease.  Still does the loud/quiet thing but it’s less noticeable with fresh grease in.

    bigginge
    Full Member

    Doh.

    I guess I can console myself knowing that the massive tub only cost me £38/kg rather than the £699.50/kg that the (perfectly sensibly sized) 20g tube works out at.

    If anyone needs any let me know; I feel I may have some going spare. 🤦‍♂️

    clubby
    Full Member

    Sounds like an eBay opportunity. Buy 20 empty lip balm tubs, fill them and punt on eBay for a fiver a time.

    bigginge
    Full Member

    Had the first ride out tonight after using the TP-42 to grease the freehub. Things started out well with no slipping on the first two descents where it had been a regular problem under hard acceleration. But at the bottom of decent number three it slipped again then went on to do it much more regularly for the rest of the ride.

    Going to try one more time with slightly less of the paste in there to see if that might help things. If that doesn’t work it all goes in the bin and I have to buy a new bike.

    bruneep
    Full Member

    I’ve checked the chain and cassette and they look to be in good condition still

    I’m still thinking its this thats worn

    Lets see pics of chain and cassette have you measured the wear on chain?

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