NachosGrande

So I was using a torque wrench, and even before I reached required torque rating for a shimano cassette I heard the lock-ring grind briefly on the thread. At least that's how I interpreted the sound. My understanding is that I may have over torqued. What should I do? Is the cassette damaged? Should I loosen the lock-ring and re-install it? I'm concerned about damaging it further, so I left it as is. riding it does not seem to affect mechanical performance.

bikepro

That sound is normal. I torque mine to around 20 ft/lbs, I'm not sure what the maximum is.

FBinNY 

Some cassette outer sprockets and lockrings have mating serrated faces. If you remember yours being that way, that's what you heard. It's normal, and intended to provide some mechanical locking so the ring can't loosen. IMO, it's not necessary, but there it is.

IME the two likely outcomes of over torquing a cassette lockring are the flange on the lockring cracking off, and if your luck is bad, the back of the freehub body cracking off.

Since you feel the ring is tight (depends on how far you got before you quit) continue riding the bike until/unless a problem develops.

NachosGrande

Thanks! Your feedback relieved my stress. The lock-ring is on tight even though I didn't reach torque rating, so I feel fine with it now.

rpenmanparker 

You can also strip the threads on the lockring if it is aluminum alloy. My standard tightness is always below the recommended torque. I'm comfy with that.

hueyhoolihan

IMO, the lockring demands no more torque than enough to keep it from backing off.

bikepro

+1 Many torque specs are the maximum torque -- as long as the item stays in place or doesn't slip is what matters.

Kopsis

Lockring torque spec is usually 40 NM (just shy of 30 ft lb). The serrated face can make it hard to gauge. You'll feel (and possibly hear) the faces ratcheting against each other. With a beam type wrench you'll see the indicator jumping all over the place. Go slow and watch the needle as you pass each tooth. When it peaks at the spec value, you're done.

Going light on the lockring torque isn't so much an issue of it coming off as it is allowing the cogs to move relative to each other. An alloy freehub with an under-spec lockring is a recipe for deep gouges on the hub splines.

jimc101

AS long as the wrench is in calibration, just tighen till it clicks or does whatever to indicate that the torque set has been reached.

For Shimano this is 40Nm, Campagnolo 50Nm, this info is printed/stamped on the lockring.

Thinking the grinding you heard was the lockring spacer being compressed, this will become damaged, and will need replacing after a number of fittings.

Retro Grouch 

I've never seen stripped lockring threads but I did once have a cassette lockring that I couldn't get to loosen. I eventually cut it off with my Dremel.

If you can see individual marks on your cassette body from the cassette cogs, that's an indicator of inadequate lockring torque.

HillRider

The recommended lockring torque by Shimano is 40 N-m (~30 ft-pounds) and by Campy it's 50N-m (~37 ft-pounds)