Torque when installing a cassette

frenchfighter
frenchfighter Posts: 30,642
edited November 2009 in Road beginners
I have just fitted a new Veloce cassette and I was just wondering how important the torque is?

For instance, they say you should tighten to 50 Nm - I don't have a torque wrench so just did it as hard as I could pretty much.

Is this ok or will there be issues if it is tightened too much or too little?

Thanks.
Contador is the Greatest

Comments

  • As you haven't stripped the threads probably not a problem.
    Neil
    Help I'm Being Oppressed
  • I don't tend to speak to anybody when I'm fitting a new cassette.
    Expertly coached by http://www.vitessecyclecoaching.co.uk/

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  • I have just fitted a new Veloce cassette and I was just wondering how important the torque is?

    For instance, they say you should tighten to 50 Nm - I don't have a torque wrench so just did it as hard as I could pretty much.

    Is this ok or will there be issues if it is tightened too much or too little?

    Thanks.

    As a rough guide I would estimate that 50Nm is probably about as hard as you can tighten it with a 'normal sized', say 6"-ish socket driver unless you're an absolute gorilla. :)

    You're tightening against the flange of the hub so it's not like you're loading bearings up or anything so I wouldn't worry about it too much.

    Of course, this information is worth exactly what you paid for it, probably less. ;)

    John.
  • Monty Dog
    Monty Dog Posts: 20,614
    50Nm is a good 'heave' - you have to press the wheel against a wall and give the wrench a firm shove to reach it - once you've done a few, you know they're very unlikely to come undone. I generally don't use a torque wrench for them, because you can't really over-tighten them and I've never had one come undone either.
    Make mine an Italian, with Campagnolo on the side..
  • Thanks for the responses. I'll give it another heave then that should be good.
    Contador is the Greatest
  • andy_wrx
    andy_wrx Posts: 3,396
    Why does it need anything like 50Nm ?

    The locknut holds the cassette on the hub and stops it falling off when the wheel is out of the frame, but that would just require it finger tight.

    Assuming there were no locknut, then when fitted on the bike the cassette would be clamped in place by the Q/R.
    But when there is a locknut, of course the Q/R clamps against the locknut.

    Even though it's subjected to a lot of torque (pedalling uphill out of the saddle for instance), the cassette can't rotate on the hub because of the splines, but if the locknut were loose the cassette would be free to waggle-about laterally a little, up and down the splines.

    I guess this might cause wear of the splines, might even cause poor gear indexing if it were a considerable amount of waggle, but I don't see that the locknut needs to be massively torqued-up to prevent it.

    Having struggled in the past to get a cassette off because the locknut was almost solid, when I put one on I don't put it on that tight at all.
  • Mister W
    Mister W Posts: 791
    The locking ring will hold the cassette tight and stop it coming undone at well below 50Nm so don't go mental on it. You may have to take it off sometime in the future and that isn't fun if it's too tight. A good pull on the ratchet handle will be fine.
  • Haha, good point guys. Maybe I'll see if it is not too tight to get off now...
    Contador is the Greatest
  • I tighten until it's 'getting tight' and then add a quarter turn.

    There seems to be a point after which it doesn't get any harder to turn it for a while which I have assumed is when you're bending the 1mm spacer ring (I'm on Shimano 10 speed). That's my indicator point. I'm sure I could crank it down another couple of turns but if all it does is bend the spacer then it's not helping.

    I agree with everyone else, doesn't really matter that much as long as it's on enough to not come off.
  • Pross
    Pross Posts: 40,217
    I'd always assumed the locking ring gets tightened more when you put a bit of power on it while riding in any case (i.e. if it was too loose the pressure would tighten the lock ring before transferring all the power into turning the wheel)?
  • alfablue
    alfablue Posts: 8,497
    I have had many a lockring come loose. Shifting in the smaller sprockets starts to get dodgy, eventually I remember to stop tweaking the indexing and check the lockring. I torque mine to 40nm (as the SRAM rings state on them) and on the bike that has constant loosening issues I also use loctite, but never has there been any problem undoing them.

    Pedalling shouldn't affect the lockring, but if there is any friction against it then the effect would be to loosen it - the sprocket is being pulled clockwise by the chain so this would undo the lockring.
  • Pross wrote:
    I'd always assumed the locking ring gets tightened more when you put a bit of power on it while riding in any case (i.e. if it was too loose the pressure would tighten the lock ring before transferring all the power into turning the wheel)?

    it cant get tightened more because the cassette is splined to the freehub body
  • dennisn
    dennisn Posts: 10,601
    FWIW I tend to put some pressure on it. On Shimano the lock ring sort of "clicks" a couple of times and that feels pretty good and that's where I leave it. No problems yet. I am sort of "heavy handed" with wrenches but can't recall stripping out any cycling nuts / bolts
    recently. I have never used a torque wrench on a bike, if that counts for anything?
  • proto
    proto Posts: 1,483
    I've got torque wrenches but have to confess to never using one when fitting a cassette lockring. I just do it up as tight as I can with a Tacx cassette lockring spanner, which is farking tight!
  • sheffsimon
    sheffsimon Posts: 1,282
    lastwords wrote:
    Pross wrote:
    I'd always assumed the locking ring gets tightened more when you put a bit of power on it while riding in any case (i.e. if it was too loose the pressure would tighten the lock ring before transferring all the power into turning the wheel)?

    it cant get tightened more because the cassette is splined to the freehub body

    Used to on old stylee cassettes, I seem to recall the bottom sprocket was the lockring also??
  • rake
    rake Posts: 3,204
    edited March 2010
  • Pross
    Pross Posts: 40,217
    SheffSimon wrote:
    lastwords wrote:
    Pross wrote:
    I'd always assumed the locking ring gets tightened more when you put a bit of power on it while riding in any case (i.e. if it was too loose the pressure would tighten the lock ring before transferring all the power into turning the wheel)?

    it cant get tightened more because the cassette is splined to the freehub body

    Used to on old stylee cassettes, I seem to recall the bottom sprocket was the lockring also??

    Yep that's what I'm used to. Obviously all changed now with these new fangled gizmos :lol:
  • Anonymous
    Anonymous Posts: 79,667
    I just do it hand tight. Makes it easier when removal time comes around...