Loose sprockets

nasahapley Posts: 717
edited September 2008 in Workshop
Hi all,

For a little over a month my bike's been developing a rattle and I couldn't figure out what it was, but it's now apparent that for some reason the sprockets have gradually worked loose. There's only a little bit of play in the smallest but a fair bit in the biggest, everything else seems to be ok (although there is a bit of play in the back wheel, I understand this is nothing unusual) . I would be very grateful if someone could tell me -

a) what's likely to have caused this,

b) if it's easy to fix myself or a bike shop job,

c) could it be at all dangerous if I ignored it for another 100 miles or so? I've got a big route planned for Saturday and limited opportunities to get to the LBS before then!

Oh and it's ultegra if that helps.



  • It could just be the lockring working loose (unusual, but not unimaginable). If so, it's a two minute job for the LBS (or you if you have the tool) to tighten. Riding with them loose might be damaging the splines on the freehub, so if you value your wheels, I'd get it sorted. Worst that can happen is the lockring undoes the whole way and the small sprockets fall off. Unlikley to cause a crash, but couild end up with wheels,chain,sprockets or mech being damaged somehow...
  • alfablue
    alfablue Posts: 8,497
    I had this on my XTR cassette, first sign was the chain jumping. I re-tightened it to the specified torque (40nm I think), but it happened again, so I reassembled it with some threadlock (medium type, easy to disassemble). You need a cassette lockring tool, about £3 or £4. It hasn't happened again since I did this.