How tight should a cassette lock ring be?

Quizmate

Hi

Just changed wheels and put my cassette back on. How tight should the lock ring be? I've done it up first finger tight then used the lock ring tool to turn it further until I've felt a couple of thud like clicks. I was worried that tightening any further might damage it so wasn't sure. Any suggestions greatly appreciated.

Monty Dog

40Nm which is a good heave - I support the wheel between the floor and my workshop wall. You'd have to really strong-arm it to damage the threads - like putting a 6ft breaker bar on your wrench.

mitchgixer6

Yeah those notches that you felt it's just the ring tightening up against the 'teeth' that are on the smallest ring. As mentioned you'd struggle to get up to 40nm without a very large breaker bar or wrench.

mamba80

the above is poor advice, 40nm is not much at all, the lock ring on ultegra up is alloy, with about 4mm of thread, many freehubs are also alloy - my snap on torque wrench is 40cm long and it does not take much to reach that 40nm figure.

without a torque wrench, I d go finger tight, using lock ring tool plus 1/2 turn.

CiB

The lockring isn't a load bearing component, it just stops the cogs from sliding off the freewheel; the splines hold it all in position. I've always spun mine up to be finger tight then just nipped it up a little bit, as opposed to grunt tight. No idea what numbers that relates to tho.

lesfirth

In old money which I think is easier to understand 40 newton /meters is about 30 foot pounds. That is 5pounds on the end of a 6 ft. breaker bar or 30 lbs. at 1 foot. You can easily break a lock ring I have done it with a ring spanner about 10 in. long on the tool! It did not damage the thread. The ring parted between the flange and the threaded bit.

bernithebiker

CiB wrote:

The lockring isn't a load bearing component, it just stops the cogs from sliding off the freewheel; the splines hold it all in position. I've always spun mine up to be finger tight then just nipped it up a little bit, as opposed to grunt tight. No idea what numbers that relates to tho.

I used to do that years ago, then a cassette came loose on me on a ride. Never again!

Now just use a dedicated lockring wrench (BBB I think) that is about 25cm long. I give it a fairly hefty tug, and that's fine - checks with the torque wrench have shown that to be about 40Nm.

k-dog

When I got a torque wrench I was surprised that 40Nm wasn't that tight - just firm with a decent length of wrench.

Matthewfalle

It's 40nm as per the writing on the lock ring. Firm but not mash. I just use a torque wrench so I have piece of mind.

desweller

The torque figure on the lock ring is 40Nm, but in reality you can get away with a lot less.

Following the advice of one of the guys on the CTC forum, I set mine so that I can undo it with a 4" handle through a modified lockring socket. I hold the cassette in place by poking an old axle through the wheel into the back of the cassette.

No problems so far, even when hauling 30kg of luggage.

mr_evil

I always do them up to the full 40Nm because it helps reduce gouging of aluminium freehub bodies by the sprockets.