Cassette lock ring undone

paulbnix

I have a Novatec D712SB hub with a SRAM 11-32 cassette.
On a ride yesterday the lock ring undid itself.
I managed to get home with some very rattly and uncertain gears and chain drops between the cassette and spokes.

The lock ring was fine and I reattached it - the thread wasn’t stripped.

I normally use a socket set and am forceful tightening the lock ring. When I undo it I need a chain whip and a mallet to start with.

I’ve noticed with this hub that the ratchet sound you hear when tightening the lock ring is a lot quieter than on other hubs - not sure if this is significant.

I don’t want this to happen again so just wondering if I should use some sort of thread lock.

jermas

Maybe you need a spacer behind the cassette. It's an 11speed freehub. Is the cassette 10 speed? Check the lock-ring is actually tightening against the cassette properly -rather than bottoming out on the freehub threads. The lack of sound when tightening suggests the lock-ring isn't tight enough on the cassette.

paulbnix

That's not my problem.

Both are 11 speed and the lock ring ends up tight with no movement of the cassette.

manglier

Use a torque wrench to tighten the lock ring. 40Nm is pretty tight and not easy to guestimate unless you are an experienced spanner bender.

Alejandrosdog

Manglier wrote:

Use a torque wrench to tighten the lock ring. 40Nm is pretty tight and not easy to guestimate unless you are an experienced spanner bender.

Except the required torque is 30 - 50nm which is the range otherwise known as properly tight to KIN tight.

If you have a torque wrench which goes to 40nm great! if not, just lean on it. Manglier is right though 40nm is "pretty tight"

your average length 3/8 wrench is difficult to overtighten without going full gorrilla

paulbnix

I do have a torque wrench but it only goes up to 25nm.
However I think I know what 40+ feels like so I’m sure that the lock ring is properly tight.

As no one has supported using a thread lock I’ll check it occasionally.

Thanks for the contributions.

pinno

Try replacing the lock ring?
I rarely tighten my Campag cassette to anywhere near recommended torque for the potential damage when removing it. It never loosens.

cycleclinic

The range is not 30-50NM. Shimano specify 40Nm. Its 40 Nm for a reason. Use 40Nm or hand it over to some one who will.
A lockring wont be damaged unless it damaged to start with by tightening to 40Nm.

Lockring must be tighened to this. Losser is asking for free hub notching and a wobbly cassette.

40Nm for a lockring does feel different to 40Nm on a set of pedals. You need a torque wrench that does this or go to a shop. Have I been clear. I hope so.

joe_totale-2

When I rode on the Flanders sportive recently the cobbles managed to loosen my cassette.
It had just been torqued to 40nm a couple of weeks before, I know as I used the big torque wrench in my LBS.
Perhaps you've been bashing along a load of potholes?

pinno

Joe Totale wrote:

Perhaps you've been bashing along a load of potholes?

What do you mean 'bashing along a load of potholes'? You meant to say, 'perhaps the cause is that he's been riding on roads in the UK'.

Alejandrosdog

thecycleclinic wrote:

The range is not 30-50NM. Shimano specify 40Nm. Its 40 Nm for a reason. Use 40Nm or hand it over to some one who will.
A lockring wont be damaged unless it damaged to start with by tightening to 40Nm.

Lockring must be tighened to this. Losser is asking for free hub notching and a wobbly cassette.

40Nm for a lockring does feel different to 40Nm on a set of pedals. You need a torque wrench that does this or go to a shop. Have I been clear. I hope so.

No it’s not.

Check the dealer tech stuff. You’re clear but just clearly wrong. Here, I’ll help you https://si.shimano.com/pdfs/dm/DM-CS0004-04-ENG.pdf

To the op not all shop mechanics are created equal. Just imagine if the cycle clinic was going to do something more challenging than putting a cassette on!

champson

To be fair, the shimano lock rings do have 40nm stamped on them.

cycleclinic

Troll alert.

cycleclinic

The only reasons why lockrings come undone is

1) damaged threads in freehub or lockring
2) dorty threads that prevent proper tightening
3) it was not done up to 40Nm regardless of what the torque wrench says.

If you get notching at 40Nm try 50Nm.

If 40Nm caused threads to unwind then one of your pedals would unwind also. So cause 3) is the most likely.

Alejandrosdog

thecycleclinic wrote:

The only reasons why lockrings come undone is

1) damaged threads in freehub or lockring
2) dorty threads that prevent proper tightening
3) it was not done up to 40Nm regardless of what the torque wrench says.

If you get notching at 40Nm try 50Nm.

If 40Nm caused threads to unwind then one of your pedals would unwind also. So cause 3) is the most likely.

When In a hole, stop digging. Your post reads like you’re drunk.

I’m surprised you have any customers at all when you come on here spouting this kind of drivel. And whilst we’re having this conversation, try saying thank you when someone points you in the right direction.

surfercyclist

Post deleted, no point in causing an argument...

yellowv2

I have had a couple of sets of wheels built by Malcolm and they are very good. I have also visited him a few times and would say he definitely knows his onions so to speak.
However he is very forthright with his opinions and when using this forum can occasionally seem abrupt to point of offending some.
It is unfortunate because he is very knowledgeable and most often correct, it would be sad we’re he to stop offering advice but a more understanding tone might be preferable?

Alejandrosdog

i think hes taken his ball home again

paulbnix

As the OP I would like to say that I agree that the lock ring needs to be tight.

I use a similar force on both my wheel sets.

They both have aluminium free hubs and neither is becoming notched.

Both have SRAM 11s cassettes.

Only this one has come undone.

There is a definite difference in the ratchet noise you hear when tightening the lock ring between the Novatec and the Miche hubs.

However I will borrow a larger torque wrench and check the torque I am using.

There is no need to take this to any LBS

pinno

paulbnix wrote:

As the OP I would like to say that I agree that the lock ring needs to be tight.

I use a similar force on both my wheel sets.

They both have aluminium free hubs and neither is becoming notched.

Both have SRAM 11s cassettes.

Only this one has come undone.

There is a definite difference in the ratchet noise you hear when tightening the lock ring between the Novatec and the Miche hubs.

However I will borrow a larger torque wrench and check the torque I am using.

There is no need to take this to any LBS

That's told 'em.

paulbnix

I've now checked the torque I have been applying when using my socket set.
I checked against a borrowed 42 Nm and upwards torque wrench and my own which maxes out at 26 Nm.
I have definitely been using in excess of 40 Nm.

A friend wondered if I had been using too much torque and the lock ring had popped off due to the strain. Can't see it myself but ...

Anyhow I'll keep an eye on it - maybe I was lax the last time I fitted it???