Wobbly cassette

[lulubel]

The cassette keeps coming loose on my new bike, and I'm not sure why. I tightened it up "nice and tight" when I first put it on, and there was no play. After 100 miles or so, it was rattling, so I figured everything had settled, and tightened it up some more. My partner and I have done this tightening 3 times now, and it still keeps coming loose after a few rides. We're using the proper tools, and an adjustable spanner with a 10in handle on the lock nut, and I don't think either of us can tighten it more than we did last time.

Are we doing something wrong?

 

[PpPete]

Don't want to apprear rude, because it's not meant that way - but adjustable spanner does not equate to "proper tool" in my book. I'm hoping the adjustable spanner is just being used as a driver for the correct splined lock ring tool?
Only thing I can think of is maybe one of the smaller (loose) sprockets is not quite lined up right? You can sometimes get the last one on "canted" over because the "odd" spline is not lined up right, then the lock ring is not bearing down on all of it.

 

[ianrauk]

Does it have/need a spacer between the cassette and the freehub?

 

[Blue Hills]

Does it have/need a spacer between the cassette and the freehub?

My thoughts as well.
How many speeds is this cassette?

 

[dellzeqq]

missing spacer's the prime suspect

 

[Globalti]

There should be a distinct clicky feeling as the lockring tightens. If there isn't, something's wrong.

 

[RecordAceFromNew]

There should be a distinct clicky feeling as the lockring tightens. If there isn't, something's wrong.

+1. Because both the sprocket side of the lock ring and the lock ring side of the smallest sprocket are serrated, so they crunch up and lock against each other and will not come loose. If that feeling is not evident then it is also likely that you can not see the smallest sprocket rising proud of the freehub, when it should be, by a mm or two. If that is not the case your cassette stack is missing something.

 

[zacklaws]

You need to be tightning it up to about 40 neutrons (Shimano) with a torque wrench which is very tight, but even so, I have had a couple come loose

 

[youngoldbloke]

Exposure to neutrons can be hazardous, since the interaction of neutrons with molecules in the body can cause disruption to molecules and atoms, and can also cause reactions which give rise to other forms of radiation (such as protons). The normal precautions of radiation protection apply: avoid exposure, stay as far from the source as possible, and keep exposure time to a minimum. Some particular thought must be given to how to protect from neutron exposure, however. For other types of radiation, e.g. alpha particles, beta particles, or gamma rays, material of a high atomic number and with high density make for good shielding; frequently lead is used. However, this approach will not work with neutrons, since the absorption of neutrons does not increase straightforwardly with atomic number, as it does with alpha, beta, and gamma radiation. Instead one needs to look at the particular interactions neutrons have with matter (see the section on detection above). For example, hydrogen rich materials are often used to shield against neutrons, since ordinary hydrogen both scatters and slows neutrons. This often means that simple concrete blocks or even paraffin-loaded plastic blocks afford better protection from neutrons than do far more dense materials. After slowing, neutrons may then be absorbed with an isotope which has high affinity for slow neutrons without causing secondary capture-radiation, such as lithium-6.
Hydrogen-rich ordinary water effects neutron absorption in nuclear fission reactors: usually neutrons are so strongly absorbed by normal water that fuel-enrichement with fissionable isotope, is required. The deuterium in heavy water has a very much lower absorption affinity for neutrons than does protium (normal light hydrogen). Deuterium is therefore used in CANDU-type reactors, in order to slow ("moderate") neutron velocity, so that they are more effective at causing nuclear fission, without capturing them.

You need to be tightning it up to about 40 neutrons (Shimano) with a torque wrench which is very tight, but even so, I have had a couple come loose

I think you mean Newtons

 

[RecordAceFromNew]

I think you mean Newtons

I think he meant Newton-metres (or Newton-meters if you are from the other side of the pond, or whatever ft-lb it translates to)

 

[lulubel]

Sorry, guys. I was busy yesterday and didn't have time to get back to this thread.

As far as I know, everything is correct. It's a 9-sp cassette on a Shimano 105 hub, without any spacers.

Yes, I've got the nut-thingy that fits into it - that's why I said said correct tools AND an adjustable spanner - and that's what we're using the adjustable spanner on. (I can't see any way you could possibly tighten it without the nut.)

It clicks as it tightens, but it's got to the point where my partner (who is a lot stronger than me) has to take a deep breath before she puts in the effort to get it to tighten just one more click. We don't own a torque wrench, and haven't got the money to spend on something that isn't absolutely essential at the moment. (I don't think a torque wrench would help to tighten it more anyway - just tell us how tight it is?)

 

[ianrauk]

Sorry, guys. I was busy yesterday and didn't have time to get back to this thread.

As far as I know, everything is correct. It's a 9-sp cassette on a Shimano 105 hub, without any spacers.

Yes, I've got the nut-thingy that fits into it - that's why I said said correct tools AND an adjustable spanner - and that's what we're using the adjustable spanner on. (I can't see any way you could possibly tighten it without the nut.)

It clicks as it tightens, but it's got to the point where my partner (who is a lot stronger than me) has to take a deep breath before she puts in the effort to get it to tighten just one more click. We don't own a torque wrench, and haven't got the money to spend on something that isn't absolutely essential at the moment. (I don't think a torque wrench would help to tighten it more anyway - just tell us how tight it is?)

No need for a torque wrench when it comes to tightening a cassette lock ring.
Perhaps try a 1mm spacer to see if it helps.

 

[Blue Hills]

no I wouldn't use a torgue wrench either.

After overtightening once (I have a tendency to do this) I thought I'd use one but it was a big mistake - slotting the torgue wrench into the Park Tools casette remover meant that I couldn't put an old skewer through it to anchor it as I then turned it with a good quality adjustable spanner - so the tool slipped out of the lock ring tearing a small bit off the teeth. Not good. Just fasten it so there are a small number of clicks - avoid my previous habit of continuing to tighten as it clicked clicked and more clicked.

 

[HLaB]

I've never used a Torque wrench on a cassette either; ,IRC mine only goes to 24Nm anyway. Ive never had a lockring work its way loose on me, I usually just tighten 3 or 4 clicks.

Edit: I did once have a loose cog, it was the elusive missing spacer

 

[Sittingduck]

It doesn't have to be mega-tight and require Hulk-like strength... I'd put money that you are missing a small spacer on the freehub. Not talking about the ones that go in between the sprockets either. Some wheels (Mavics, I think?) need a seperate small metal ring that you slide onto the hub body, before slotting on the cassette.