cpjolicoeur

I'm in the process of building up my first frame set from scratch.

Only seem that I had any issues with today was installing the cassette onto the hub. When I tried to torque down the lockring, it seemed like if I really gave it a bit of torque then the whole cassette would tighten down too much. It would prevent the cassette from rotating on the freewheel at all. I had to loosen it up a bit to allow the cassette to rotate freely on the freewheel, but that means its not techincally torqued to the spec'd 40Nm.

Is this an issue? Am I missing something simple for torqueing down a cassette?

The cassette is a SRAM PG1070 and the wheels are Neuvation M28X Aero.

Burton

Regardless of how much or how littly you torque down a cassette lockring, the cassette / hub assembly should turn freely in the non-drive direction.

There is a possibility that a spacer ring is needed as a standoff on that cassette and without it you may be jambing the cassette against the spokes. That 40Nm is a MIN value and you need it so suggest you check things over carefully.

reptilezs

check for any rivets or bolts on the cassette rubbing on the hub shell. sram cassettes do not use the 1mm spacer like shimano does but it may be necessary to get it to freewheel

cpjolicoeur

Yeah, my cassette didn't come with any extra spacers that I know of, just he normal spacers that go between the cogs. Where would I pick up one and how can I know for sure if I need a spacer behind the cassette?

reptilezs

look for what the problem is first. the evidence will lead to the solution

cpjolicoeur

I went and checked again. I took the whole cassette off and put everything back on fresh again.

When I begin to tighten down the lockring, the cassette does not hit the spokes at all, and no part of the largest cog seems to be making any contact with the hub. They are just bumped up against the raised edge on the freewheel.

When I crank down on the lockring to begin to torque it, it almost feels like a type of grinding. Moving the locking a small bit you can almost feel it grind and make little "hops" or "bumps" against a notch or something.

I took off the lockring and inspected it, and there is some kind of small aluminum washer that was a bit bunched up and not sitting correctly. I took it off completely and here is a photo of it.



I only took it off because it was obvious it wasnt seated properly and was bunched up and crimped in a few places. I thought that maybe this small washer was causing the problems. No difference though, once the washer was removed. If I tighten the lockring down to any significant level, then the cassette stops rotating on the freewheel.

reptilezs

is the back of the cassette free of obstruction when torqued down?

cpjolicoeur

Yes, the back of the cassette (closest to the spokes) appears to be free from obstruction. I dont see the cassette hitting anything back there, and when I torque down it doesnt appear that the cassette is getting any closer to the spokes either.

davidad

Sounds like the lock ring is pushing on the dust shield in the freehub body making it rub against the bearings. Try a 1mm spacer behind the cassette and see if that helps.

cpjolicoeur

Where would I get a 1mm spacer? Do I have to find a LBS or do I need to order one somewhere?

Yellowbeard

Bike shop should have them.

cpjolicoeur

So, I'm still curious why I will need a 1mm spacer when the SRAM cassette documents dont say that one is required like the Shimano cassettes?

What I hear you all saying is that the cassette is set to far back on the freewheel and the lockring is screwing down tighter into the grooves of the freehub than it actually should be?

laura*

That's normal. The backside of the lockring, and the face of the first position cog both have little ridges. These help prevent the lockring from loosening. When tightening the lockring, they make a "zipping" noise and also cause the lockring to move in little jumps.

Better quality cassettes have this thin washer between the lockring and first cog. It makes it easier to tighten the lockring. If the mechanic doesn't exercise care, the washer can be a "single use only" item.


I wonder if the OP's cassette tool is running into something. Perhaps the OP has a bent axle and it is pressing up against the tool.

Something good to try: Install the lockring by itself without the cassette.

Oh, and BTW, the nouns freewheel and cassette don't go together. A hub uses one or the other. I assume that what the OP is calling the "freewheel" is actually the "freehub body".

cpjolicoeur

I'm aware of the ridges on the lockring and the issue I described definitely is not those. They would not cause the freehub to stop turning completely under moderate torque.

Also, I'm using a brand new rim/hub so I doubt it would be a bent axle. I can install the locking fine by hand. It's torquing it down that causes problems with the freehub rotation.

The depth of the threads on the lockring appear to be deeper than the threads on the freehub body it screws into. Not sure this is a problem, since the smallest cog sticks a bit above the end of the freehub, but maybe it doesnt stick up enough and that is why other users are suggesting a 1mm spacer between the cassette and the spoke-side of the freehub?

cpjolicoeur

btw, this suggestion was almost disastrous and I'm glad I thought it through before tightening down the lockring with any significant force. If I had tried to tighten it with no cassette, it would have been a huge pain to remove again since I wouldnt have the leverage of the chain whip on the cassette to loosen it from the freehub.

jccaclimber

So put a single cog on, just not the smallest one and then try it.

Al1943

Is it a Mavic hub? Most of those require a 2 mm spacer washer because a Mavic cassette is 2 mm wider than Shimano or Sram.

cpjolicoeur

I'm not sure what kind of hub it is. It's a brand new Neuvation M28X Wheelset from Neuvation but I have no idea what brand of hubs they use.

JTGraphics

I once had an issue with someones wheel like yours I backed off the axle bearing lock rings installed the cassatte and reset the bearing and all was good.
Don't know what was really causing it but it helped

laura*

Ooops! Sorry.

But at least we got the information that this test was supposed to return:

Cassettes do seem to compress a bit when the lockring is tightened - especially new ones and old dirty ones.

It sounds like your non-Shimano non-SRAM freehub might be designed for a thinner lockring. (They do vary in thickness!)

cpjolicoeur

The freehub is a Shimano/SRAM freehub, at least that is what was specified and ordered from Neuvation.

cpjolicoeur

So I've been doing more research online and it appears that maybe my issues are because my cassette has an 11t as the smallest cog and not a 12t?

I've seen sites that say with a 11t cog you need something called a "C" hub (or a compact) hub. Does this sound legit and related to my issue, because my cassette does have an 11t as the smallest cog.

mechBgon

That's not likely, since 11-tooth cassette cogs have been extremely common for over a decade. Do check that the bolt holding most of the cassette together is not protruding from the rear of the large cog (it uses a 1.5mm hex key).

My best guess is that when you tighten the lockring, it flexes the other end of the freehub body enough to cause some part of it to drag on the hub shell. Consider making a warranty claim with Neuvation about it, because the problem you described should not be happening and it's not your job to come up with the solution.

cpjolicoeur

The issue was solved with a 1mm spacer behind the cassette. Maybe Neuvation uses Mavic hubs (or the same style hubs) and thus required the 1mm spacer that was suggested by several people in the thread. Thanks all for the help and input.