SSP

I'm trying to install a Dura-Ace cassette on a Zip 404, but no matter what I do I can't seem to get the threads of the cassette lockring to catch on the threads in the freehub body.

I've tried removing the 11 tooth cog and carefully screwing in the lockring, but even when it catches, it only turns about 1/8th of a turn and seems to seize up (like it may be cross-threaded, but it doesn't look cross-threaded and I've tried to be careful to not force it).

Any ideas?

urbanknight

Is there a spacer on the back of your cassette? Try removing that first. If that doesn't work, did the lockring come with the cassette? On my bike with Campy, I quickly realized that the lockring with my Miche cassette is shorter than the one with my Veloce cassette, so I couldn't interchange them.

Bob Dopolina 

Tried a little grease on the threads?

SSP

1) No spacer on the back, and the lockring was packaged with the cassette. Everything (cassette and wheel/hub) is brand new. The hub is by Zipp, and the cassette is Shimano Dura-Ace.

2) Yes - I've greased the threads.


Looks like I'll have to drive the car to work today instead of riding, and take the wheel to the bike shop to see if a pro can diagnose/fix it.

DMF 

The spacer on the lockring isn't normally separate. It's a thin wavy captive washer that doesn't provide a flat surface to get the ring perpendicular to the axle.

Two tricks:

1. Use the lockring tool to install it, especially if it has the lead pin that sits in the axle.
   
2. Turn the lockring backwards until you feel a bump as the start of the male thread passes over the start of the female thread. Then turn it forward so that they engage.

SSP

Thanks for the tips...but still no joy. The lockring does has the captive wavy washer...I pushed it down so hopefully it's not interfering.

And my lockring tool does have a lead pin. I tried carefully turning backwards, felt the "bump" then started turning forwards. It seems to engage, but only goes about 1/8 turn before significant resistance is felt. Looking at the lockring from the side, it appears perfectly parallel to the cogs (i.e., not cross-threaded). It may just need some additional torque to get it going, but I'm afraid to do that for fear of screwing up the hub body and/or lockring threads.

Hopefully, the pro wrench will be able to get it installed OK.

masiman

Have you tried using the skewer to provide clamp pressure to get it started? I had trouble a few months ago with a lockring and I think I did that.

Cynikal 

He can't do that if his tool has a lead pin. If he has the standard park then he is fine.

SSP

Correct - my tool (from Performance), has the lead pin. I've tried applying downward pressure as the threads first engage, but still it seizes up. I suspect there may be a problem with the threads in the hub body...perhaps they just need to be chased out a bit, or perhaps it just needs more torque to get past some little defect. I'll report back later today after taking it to the bike shop.

DScott

Are there different threads for Campy vs. Shimano? Maybe your hub is Campy threaded?

SSP

Yes...there are. The wheels came with the bike and components, which were all Shimano. It's supposed to be a Shimano compatible hub, and it looks like the right size and thread pitch. I'm taking it to the bike shop at noon (PDT), and hopefully will have an answer to this problem later today.

joejack951

Possibly but you couldn't put a Shimano cassette on a Campy freehub (or vice versa). Good question about the thread pitch though. Anyone know the answer?

rschulze

If this is a new Zipp 404 then it's a common problem, I went through the same thing. The shop I brought it to said they had been flooded with these. The threads are the right size, just not cut deep enough. What the shop did for me is to take a steel, not alloy, lock ring and lube the threads with cutting oil and used the ring carefully and cut the threads deeper. Worked like a charm, now the alloy ring works fine. I'm not suggesting you try this on your own, you may screw it up worse, kust passing on my experience with the same issue

masiman

Got it. I have seen but never used one of those. I was not quite sure what was meant by "lead pin".

Thanks.

SSP

Well, it stumped the mechanic at my LBS too.

He tried a couple of different lock rings, all with the same results. He also took a "pick" and went round the threads in the hub body...he said he couldn't really see any problem areas, but clearly it's not right because the lock ring refuses to spin on.

SSP

I suspect that may be the problem...I'm going to call the shop that sold me the wheels and see what they say before I attempt any more "forceful" solutions.

SSP

Well, I've contacted Zipp tech support directly, and apparently they are aware of the problem. According to their reply:

Thank you for contacting Zipp re Shinamo cassette body.

Please call our CS desk and get them to walk you through the return process. There are tolerance stackup issues from Shimano changing their thread clearances. We will send you a remachined cassette that will work. Sincere apologies for the hassles.

Please feel free to contact us if you have any additional questions.

joejack951

If your mechanic has a thread file, he could use that to clean up the threads in the freehub if one is nicked or if the minor/major diameter of the threads is bad. He's more likely to have the thread file than the correct size tap

SSP

He had a sharp "pick" tool and ran it around inside the threads of the freehub body...mostly to explore and see if there were any obvious signs of damage. He said he didn't really see any damaged threads on either the freehub body, or the cassette lockring. But it was still not possible for him to get the lockring to thread in more than 1/8 turn (without applying mechanical force).

This is consistent with the email I got from Zipp that it's a "manufacturing tolerance" issue in their hub, and not the result of damaged or mangled threads.

Bob Dopolina 

The thread pitch and diameter are different for Campagnolo and Shimano. NOT interchangeable (no surprise there...)

DMF 

Ah, I see. It was all Shimano's fault.


So, if Shimano has changed their clearances, wouldn't that make their own components incompatible? 'Course no one has reported that as a problem...

SSP

FWIW, I spoke to a customer service rep at Zipp this morning, and offered two solutions:

1) He recommended I try the "ream it" approach by using an Ultegra (steel) lockring....as recommended above, oil it up, start it carefully, then put enough torque on it to force it to expand/cut the threads in the Zipp freehub body.

or,

2) Mail the freehub body back to Zipp for a free replacement.

I'm going to try #1 this evening, and if I bugger it up, or it doesn't seem right, I'll mail it back to them.

Seem fair enough...I just want to get on with this build project and not wait a week or more for turnaround from Zipp.

DMF 

I wouldn't want to try #1. Alloy is more liable to split than bend. If you can find the appropriate tap and re-cut the threads, then fine. Try calling some machine shops, but don't get your hopes up.

Waldo

Actually, it is a case of Shimano not holding parts to spec and our tight clearance biting us. I'm guessing this will fall on deaf ears but here goes anyway.

In the past year or so we've had a few different occasions where customers have called with this issue. We haven't had any reports of problems with SRAM, American Classic, or other cassettes that use the same body (nor Campy cassettes on the Campy body).

Checking our freehub bodies shows that they are in spec; checking Shimano's lockrings shows that they are out of spec. However, it's not quite so cut and dry. I'll save the long explanation, but Shimano's lockrings are ordinarily actually closer to a different thread than the spec, and as their tools wear they deviate even further from the spec.

To answer your question, the issue is that our clearances were tight enough to create an issue with the parts that are now furthest from the stated specification. Shimano and others do not have this issue as their clearances are open enough to accommodate parts that are out of spec.

I'm sure people are more inclined to believe Shimano's reputation than ours, but we've gaged batches of lockrings each time this has become an issue and seen the same problem. As I said before, our parts are to the ISO spec and we've never had an issue with any other manufacturers' lockrings using the same freehub body. We have opened up our threads to accommodate the wider variability; this has taken care of the issue with Shimano's lockrings.

SSP, I'm in engineering so I don't know how the customer service guys are handling this but I'd ask if they can just send you a new freehub body prior to receiving the old one. If they get it out on Monday you should have it for the weekend. PM me if you have any questions or need additional help.

SSP

Thanks for the explanation.

FWIW, I tried the "ream it out using a steel lockring" technique yesterday evening, but gave up on it after half an hour of trying. It seemed to be opening up the threads somewhat, but only marginally, and I was worried about damaging the hub body.

So, I'll call customer service on Monday, and mail my hub body back for replacement.