Campy Neutron Hub/Freehub Issues

[boysa]

Two issues:

First, I was doing a quick service on my Campy Neutron hubs, and in the process of putting it all back together came across something that has me stumped. I have the hub all set, but when I put the cassette back on, as I tighten down the lockring I can start to feel "grating" as I spin the hub. If I put the lockring on with only a few "clicks" past hand tight, no issues, but if I even attempt to approach 40nm, no good. Since these are the only Campy hubs I have, I don't have another set to compare against. I've swapped two different lockrings, same result. I'm trying to imagine why this could/would happen, and I'm baffled.

Is this a sign the freehub bearings could be trashed? I don't have many miles on these, although, the second issue I have is the freehub locknut has come loose two or three times now. Not sure why that is happening, and was considering putting some locktite on the threads. Good idea?

Thanks for any advice...

[Calnago]

Hmmm... you have me curious as well. Not going to say I know what it is at this point. Are you the only owner? What prompted you to take it apart in the first place... just hadn't been done for a long time, not running smooth, suspect bearings? I wonder if one or more of the plastic spacers are cracked or broken, particular the one between the second largest cluster of cogs where the individual ones start. 11speed or 10speed? I suppose it might be the bearings, but if you don't have many miles on it as you say, then seems kind of unlikely. How old is the wheel? Does it have 3 pawls with individual springs or does it have the pawls all held with a fine wire type spring that goes around the whole thing? Is that set in properly? Were all the hub bearings in their carrier and seated nicely in the races before reassembly? I'm just thinking out loud here to maybe spark something with you that you noticed while working on it. It's concerning that your lockrings come loose as well. What size is the cassette? If your smallest cog is an 11 tooth cog, do you have the proper lockring? I will follow this thread because I'm curious now too. Good luck.

[boysa]

Whoa! I'll try to summarize:

1. Neutron Ultra Wheelset (2014/15?)
2. Only owner, approx. 1500mi
3. Just wanted to service the hubs due to some rainy days/salty air here in the islands; plus a need to tinker
4. 11spd cassette, correct lockrings for 11T, no broken spacers
5. Pawls held by wire spring
6. Bearings all look good. In fact, hub seems perfect until I tighten down the cassette (which makes no sense because there shouldn't be any pressure applied to the hub when I tighten the lockring, right?)
7. The lockrings don't come loose... but the "locknut," or whatever the proper terminology is for the nut that holds the freehub in place

I miss anything? It seems to me the freehub bearings could be the only culprit.

[jekyll man]

You've not put the DS hub bearing shield (white rubber on all the ones I've done) in properly.

There's a cut out ring for the outer edge to sit in; its probably not gone in this.


To stop the locknut coming undone, put the freehub onto the axle while out of the hub. Holding the axle in a suitable vice, fasten the locknut tight. Some used to have a grub screw in to stop them undoing.
Replace axle, freehub unit back ito hub, and take play out using NDS adjuster.
Next time, remove axle and freehub together, starting at NDS.

[boysa]

Thanks, but unfortunately no joy.

I pulled the whole thing apart, inspected the bearing shields, and they were in their grooves. Just to be sure, I removed & reinstalled them, but the issue persists. What is strange is if I spin the freehub/axle in my hand with the cassette removed, it feels much better than once I have the cassette locked down. It has to be the cartridge bearings in the cassette. I thought maybe the lockring could be bottoming out and disrupting the cartridge bearing, but that would be really crazy. Again, possible, but it would mean the freehub is faulty and needs to be replaced. I might just pick one up and see what happens if I replace it.

I tightened the locknut down as hard as I could. If it comes loose again, I'll certainly consider an alternative.

Thanks!

[micky]

Recently purchased a set of used Neutron Ultra and changed the freehub with a 11 speed one.
Without cassette, the freehub/hub were spinning veeeery smoothly, but once I put on the cassette, it just wasnt spinning.

Opened the whole hub more than once to try to understand what the problem was, everything was alright beside the "nut" at the end of the freehub (donno the exact term for this) which hold the cassette; when closing the lockring, it was pressed against the cassette and evertything was almost "locked".
I had to get one made by hand (luckily I had the right help from a mate) which was slightly shorter; the problem was finally solved.

Donno if this is your case, hope it helps!

[boysa]

Very interesting. Are you referring to the nut which holds the freehub onto the axle? The one which is reverse threaded? Underneath that, there is a spacer. Perhaps it was the spacer that is too long? I could file one or both of those down to make them shorter and see if it works.

Grazie tante!

[boysa]

But wait... the cassette lockring doesn't actually touch the nut which holds the freehub onto the axle. Now I'm even more confused...

[bikerjulio]

I gave this a bit of thought while the site was down just now.

OP, were you aware that the freehub nut is reverse threaded?

The story points to something that was damaged in the process, and the nut is the first obvious choice.

Playing with a hub on the bench here, I am also at a bit of a loss as to why installing a cassette would cause a further problem though.

[boysa]

Yes, I knew it was reverse.

Thinking back to one of Calnago's questions, as to why I pulled it apart in the first place, I remember straight out of the box thinking, "This is not as smooth as I expected." With that in the back of my mind, I think I felt some adjustment was in order.

[Calnago]

The reason I asked was to determine if it was perfectly fine before you pulled it apart which, if it was, would indicate something went awry during disassembly/reassembly. But now that you say it didn't seem right from the beginning, maybe there is a defect or maybe it was assembled incorrectly at the factory. A long shot but I suppose it could happen. The very first pair of Bora Ultras I ever laid hands had me so enthralled I had to pull them completely apart just to see how everything works inside and see what these CULT bearings were all about before their first ride even. Lucky I did because to my surprise I found a little aluminum shard nestled in their amongst the bearings. So you never know. But without seeing everything you've got there in at a loss as to what you're even experiencing let alone knowing what could be the cause.

[tommasini]

One thought

The freehub goes on until the inner bearing (closest to the hub) rests on a shoulder of the axle. Since the issue shows up as the cassette lockring is tightened - pershaps the axle and cassette body side to side tolerances lined up on this one such that the cassette body flanges that stop the cassette from going inboard are just a very small distance off the seal. As the lockring is tightened perhaps the pressure of the cassette against those small aluminum nubs that locate the cassette side to side are flexing just enough to allow more pressure from the cassette body against the seal.

Just a thought.

[boysa]

That is a interesting hypothesis, and frankly, would fall within the realm of what could cause this issue. There's not a lot which could cause this to happen. If I install the cassette, tighten it by hand, then grab my wrench and begin to crank, I can get about 15 "clicks" and all is fine. Around the 16th "click" the grating begins. It's not massive, but with each successive click it gets worse.

[androidavies]

Another couple of suggestions......!

Put the wheel in your frame without the cassette fitted, see if the freehub will freewheel if you flick it backwards by hand, you can usually feel any binding or roughness in the freehub body bearings more easily without the extra weight/leverage of the cassette fitted. That's fitted to the bike, with all the normal adjustments done to the axle/hub, prior to fitting the cassette.
Secondly, but I think unlikely, since it sounds like all was well before the hub was dismantled... I've several times encountered a cracked Campag freehub body, with the crack running from the outside edge of the body at the base of one of the cutouts that locate the sprocket lugs. First indication was noticeable play in the body with the sprockets mounted, and it also started to seize as the lockring was tightened up. I thought that the crack in the body was being wound open by the twisting torque on the threads and the body was then starting to bind on the hub shell. I didn't count the number of "clicks".

As also previously requested, let us know if you get the problem resolved, although just keeping a check on the lockring from time to time may be more convenient!

[Valbrona]

The cassette lockring is possibly bottoming out on the outermost cartridge bearing in the freehub body. What lockring you using? Get an alloy one and file some off.