herbarium

I built my first pair of wheels (successfully!) but soon realized that the Miche Primato hub I bought, used, has stripped threads on the lock ring. The cog threads are fine. The hub only has a fixed side, nothing on the other.

Is there anyway that I can chase or tap the lock ring threads? When I try to thread the lock ring, it catches one thread on one side, but then slips. Is there something I can do, like file the first thread ring down to get to the second thread? Or any way to chase these threads somehow?

I know that some pro track racers don't bother with lock rings. I know that I can thread a single speed sprocket on the cog threads and use it as a single speed. I can use blue locktite, etc. etc. BUT I would like to get it working as intended, a cog with a lock ring. Any advice would be appreciated. (crosspost from fixed gear forum, looking for more answers).

dsbrantjr

Tapping or chasing cannot add metal; tapping cuts metal away and chasing pushes it around to try and re-form the threads, but the re-formed threads will be weaker than the original ones. Best solution would be to try and find a replacement lock ring.

Dan Burkhart 

I'm sure you already know this, but just to be sure, you do know lock rings are left hand thread, right? I'm having a hard time telling from the photo if the hub is stepped down to the smaller diameter of lock ring threads.

79pmooney

I bought a Primato flip-fop hub (both sides fixed) an had thread issues from day one. Not enough threads. It was also the standard (ISO?) threading, Previous Miches I've used (4 or 5) had the larger diameter lockring threading used by only a few companies. (I've had 2 bell shaped 12-tooth lockrings cut to the Miche diameter. And yes, literally cut. On a lathe with a cutting tool, not a tap.)

I wonder if your lockring should be an ISO and you've got a larger diametered Miche standard. (Miche makes both so the name Miche on it won't tell you. Might see if another lockring threads on easily.

Edit: Oh, if you want to use a 13 tooth cog and that is a Miche larger diameter thread, you have ot use a 12-tooth lockring. The chain will ride up on the Miche ring and drop into the spanner slots periodically. making setting chain tension impossible. It's a long story I won't tell here, but that cursed little feature may well have saved my life 6 years ago.

herbarium

yup

Huh, so there are different sized lockings? This might be the case because, the hub is an older style anyway. Do you know this diameter measure? Otherwise I'll try all the 3 different lock rings I have.

herbarium

well that was a lot of wasted effort for learning something new... there are various lock ring threading standards/pitches! Of course, the Italians have something different.
https://www.lfgss.com/conversations/172429/

thanks for the tip 79pmooney

hopefully, when the proper lock ring comes in the mail, the threads on the hub won't be totally busted.

Andrew R Stewart 

Glad that you have a possible solution. However I'll add comments boardering on the cynical. One issue with fixed gears and how they are used these days is that few riders also use a brake. Back when the whole currier thing was starting (at least for where I was living and owning a LBS) a number of messengers went to fixed set ups and removed their brakes. Most who did this got pretty cheap hubs and lock rings and really didn't know how to maintain them,. or much else about their bikes sometimes. We saw a number (for how many were in use in the early 1990s in Cleveland) that stripped the ring's threads on the hub. My opinion then was that while the original intended use of an alloy hubbed fixed gear was for track racing, where if one had to slow/stop quickly one lost the race. Yet they were skid stopping many times a day. Add to this the then lack of maintaining the lockring's tightness meant that the cog would unthread and retighten frequently. The cog's thread shoulder stopped the cog's movement on tightening with the far less strong lockring's threads taking the toll of those stop forces (which are higher then the accelerations can ever be), Thus the hub's ring threads soon enough wore down and/or the ring skipped threads. Of course this hindered future keeping a routinely visited ring from staying put. We replaced a number of those cheap hubs, back then a wheel rebuild.

These days it seems that some of this is less then earlier. More seem to know about proper maintenance and I don't see the skid stopping as common as I used to. Likely because I now live in a city with no real currier activity and fixed bikes are more for general getting around then working as fast as one can to max pay. Still I strongly suggest a proper wheel brake or brakes be used on the road with a fixed cog. If for no other reason that stopping with the front brake can save you a lot of grief and should an incident (not sure I would call a conscious choice to flaunt the law to be an accident) ever go to court the lack of a brake in many states can be a reason to dismiss an injury claim. Andy

tFUnK

Hey OP, I saw this thread title and immediately thought of you 😆

I do hope the hub works out 😉 I didn't know the Italians had a different standard, either🤷‍♂️

herbarium

Hey bud, yea me neither, I wish we would have both known!!

JohnDThompson 

Not to mention, there are at least three track lockring thread specs. IIRC, Miche uses the Campagnolo thread spec; others use ISO/English, and a small minority may be metric:


Source: Sutherland's 4th Edition

herbarium

Hey Andy, you have some good points there. At one point, I too fell into that once fell into that thinking, that front brakes are not cool, that the messenger mentality of riding as fast as you can without slowing down was the way to do things. No I always wear a helmet and a front brake on my fixed gears.

I am wondering, as you point out, when this mentality change? Do you think it's more that people are more aware of their own safety (to themselves and others)? Or do you think that the nature of courier business has changed, thus affecting the attitudes of fixed gear riders? (This is sounding like a academic essay now, which I may one day research )