Mr. Spadoni 

In 40 plus years messing about with bikes, last summer, for the very first time, I built up a frame with Italian threading.

It is a early 80's Merckx, found here in BF. It is not pristine, but it is a joy to ride.

Just this morning, while riding it on an errand, I thought to myself, " this bike is a joy to ride."

Then I looked down at the crankset and noticed that there seemed to be a lot of space between the BB and the fixed cup. I stopped and looked a bit closer. The fixed cup had loosened up.

Now, I had heard that Italian thread BBs were prone to do this, but had always thought it was a myth. I guess not.

BB is a Shimano UN55. Threads were greased as per Shimano tech sheet. Loctite was likely used as there is a fairly new tube on the bench and I would not have used it on anything else. Not sure if I got out the torque wrench but probably did. Mileage on the bike is low: HB tape is still clean from build and there is no clearance for fenders so it was not ridden more than a few times over the winter.

Here's the question: Do I tear it apart, loctite every inch of the threads, and have Young Spadoni, who is possessed of the strength to break two frames in the last year do the final tightening ? Or do I go old school and out on a real fixed cup that can actually be snugged up should it come loose without having to pull the cranks? How do I know that is possible? I had a Raleigh that when transported in the back of a friend's VW beetle would develop a loose fixed cup after about 50 miles. I still have the plumber's drain wrench that I used to deal with that problem.

Suggestions?

repechage

Italian / Japanese conflict

seriously- take it apart- clean drive side threads on both sides, loctite drive side

jdawginsc 

It seems the Italian thread cartridges might have an issue with regression loosening...is that what it’s called...

haven’t had the issue with Campy cartridges though as yet.

Reynolds 

Maybe it's just luck - but I've installed quite a few Italian threaded BBs, both old school and cartridge, and never had them come loose. I use just grease and tighten them VERY hard with a 16" wrench.

Andy_K 

I've had this problem with three different French bikes (1 VO BB, 1 IRD, and one Phil), in each case I had neglected to use Loctite. Blue Loctite on the second try took care of it.

For some reason it hasn't happened to me with an Italian yet. I use UN55 on most of them.

bikingshearer 

Been there, done that. I had the problem (once) with a Campy Record or Chorus BB. Blue loctite and tightening it until it screamed for mercy did the trick there.

I have recently had the same problem with a Phil Wood BB. Twice. I tried blue loctite and tightening hard, but I guess I didn't tighten it enough as it worked loose again. Because of the way Phil retaining rings are set up, you are tightening the drive side ring against the BB unit, not the frame, and I've been reluctant to go at it as hard as I would with a more conventional set-up. I hope I tightened it enough this time (a week or two ago). We shall see.

oneclick 

Ditto.

ridelikeaturtle

I find these threads so interesting, as when I replaced the Italian BB on my old steel Fondriest (with a Campy square taper BB), tightening it too much (and really much at all) put a lot of preload on the bearings, making it very rough. So... I just didn't tighten it much at all really.

... and it's been fine! I was totally expecting it to be coming apart.

oneclick 

It's easy enough to understand if you imagine the axle, balls, and cup as a planetary gear system.

Focus on the ball at the top of the cup.
The axle (usually) rotates clockwise as seen from the drive side.
The top part of the axle is moving forward.
That drives the bottom of the ball forward and the top rearward.
The top of the ball drives the cup rearward - anti-clockwise - unscrewing a right-hand-thead.

Not just the Italians, the French cups also need grease and GRUNT to set them.

thinktubes 

Been there, done that - blue Loctite for the win

rccardr 

Clean threads and a schmear of Shoo Goo. Stays tacky, keeps it from starting to regress yet is easy to remove for servicing when required.

”My Italian bikes wear Shoo Goo or they wear nothing at all.”

gearbasher

All my bikes have Italian threads. I grease the threads (to keep them from creaking) and tighten to the recommended torque. I never had one come loose.

iab

Once I had an Italian fixed cup come loose. I tightened it a bit more, and Bob's yer uncle. I have never used anything other than grease on threads. ymmv.

Mr. Spadoni 

Shoe goo? Hmm. First go at the internets on “loose BB” turned up a bunch of replies from a bunch of mountain bikers that used PTFE tape to deal with the problem. Shoe goo or tape would seem to dampen the force of the bearings, right?
Whole thing is interesting. One more reason I wish I had had a physics teacher who cared about something other than having us draw maps of the constellations.

obrentharris 

I would guess that the grease negated the effect of the loctite. As others have suggested, clean the threads then apply only the loctite.
Brent

repechage

if enough threads show - a lockring might be possible...
or, have Jim Merz machine an alternate- need not be an exact Phil type- could be appearing like a traditional cup with enough wall to have threads exposed and add a lockring...

if the threads are a bit “loose”, Campagnolo did make 36.5 mm cups.

gugie 

Phew, from the title I thought it was a personal issue.

jethin

I had this happen once. I’ll second torque as a “fix” and first checking that the bb is faced square. I’ve personally never used loctite, and wouldn’t unless it was a last resort.

bikingshearer 

Considering the relationships some of us have with our bikes, it probably is personal.

Mr. Spadoni 

might be room for a lock ring.. will consider that. Always thought it odd that fixed cup was one of the few regularly serviced parts on a bike that didn’t have some sort of washer or second clamp.

jdawginsc 

That's the best description of it I have heard so far...

Andy_K 

Sonny went over to take care of it, but he got shot on the causeway.

I thought it was going to be like my Italian problem — more Italian bikes keep turning up in my garage.