Campag Chorus BB Threadlock

[Colin Stanley]

Hi,
Am endeavouring to install one of these on an old steel frame. The threads are ok as I have just removed a similar one, but it was too long. The threadlock on the fixing cups doesn't look too powerful. As I have had the left fixing cup back and forth to ensure a free bearing, should I use some new threadlock. It hasn't been out, just back and forth. If it was on a car, and I was using a proprietary threadlock, I would be happy that it would be ok. However, the Campag instructions are less than helpful in this respect. Has anyone had a LH fixing cup come out because it was not locked properly?

[Mick F]

No, never.

Why do you need threadlock? Is it because your BB cage is misaligned?

The instructions just say to tighten it to so-so-torque unless the axle goes tight, and then to use threadlock. Ordinarily, threadlock shouldn't be necessary.

[Colin Stanley]

Mick,
Both the RH and LH fixing cups come with what looks like a smear of threadlock.
Just reread the instructions. Pity that they didn't ask an English engineer to write them. They recommend a tightening torque of 70 Nm for both cups. Then they write that if you notice an increase in axle pin rotation friction..........unscrew the LH support (they mean cup), apply threadlock (I think they mean apply extra threadlock) then retighten to 30 Nm. So a choice of torque!

Having followed their initial torque instruction, I just backed off the LH cup, until the axle was free again. I didn't remove the cup, so I didn't apply extra threadlock. Just hope I haven't damaged the axle and cartridge by following their initial instruction.

The previous Chorus BB I installed the other day (which again had what looked like threadlock on the cups) didn't have any trouble like this, it went in sweet as a nut. It's just that I wanted a better chain line using a shorter axle on this particular steel frame.

[Mick F]

Most of the Campag stuff comes with threadlock. I took delivery of a Chorus Triple BB the other day, ready for my Mercian, I notice it's got threadlock on like you say.

The crank bolts had it on, but I never re-apply when I re-fit the cranks. Ditto the derailleur nuts and bolts.

I wonder what other people do.......

[ddddddd]

threadlock...
Has anyone had a LH fixing cup come out because it was not locked properly?

Actually, I had problems with LH cups tightening up*. This is what causes the:

... increase in axle pin rotation friction

(If I have understod them correctly.)


*With a different frame type and different BB to yours.

[hamster]

It may be that they do this as general instructions for all their BBs. As Italian frames have the BB tightening the wrong way (so it can accidentally loosen) I would have thought that threadlock in that case would be a good idea. However, for a normal UK thread it's a bit pointless as the pedalling action tightens the cups (in theory at least.)

[PW]

Agreed. For normal British B/Bs I clean the threads, apply plenty of grease & tighten them up as far as I can with a spanner which has a handle length of around a foot. I've never trashed the threads & never had one come loose unless it had been installed by a bike shop!