Binding in Campagnolo Ultratorque bottom bracket

[chriscross1966]

Hi folks...

Well I've managed to put a Campy Ultratorque in my Brompton but I have an issue... if I tighten the axle screw up to stated torque (55nm) then the pedals are very stiff to turn, it reminds me of the sensation after I overtightened the old cup and cone bottom bracket on my Raleigh Chopper when I was 10...

I've tapped out the bottom bracket and faced it using the Lifeline kit from Wiggle, that all went well, though facing took way longer than I expected. Having looked at the BB before I started I can see why people do it, the paint was the least of the worries there, on both sides there was extrusion of the threads outwards making the surface completely uneven... anyway, that isn't the case now, the cups should be completely square and torqueing them in was a joy, I could run them in by hand until they touched down, then it took a tiny amount of movement on the torque wrench to take them to 35nm.... about an eighth of a turn, if that... So why is it binding?

Would I be advised to take the wave washer out? I've got a nasty feeling that I'm going to have to space the right hand cup out in the longer term to keep the spider from fouling the rear frame as it folds, If I wanted to add a millimetre to the drive side with some shims I have on order would that mean I have to shave a millimetre off the left hand of the bracket or are there ways to get round this?

 

[chriscross1966]

OK well as a quick hack I've taken the wavy washer out and it is now not binding (hurrah) and is torqued up to 55nm (hurrah2) but I seem to have given the bearings a bit of a hammering during my previous bodgery (bugger) .... thankfully they were fairly cheap NTN6805JRLLB's so I'll order anohter pair.

 

[Tin Pot]

I've not had this issue.

Did you leave the antiseize stuff on the cups?

 

[chriscross1966]

Figured it out now..... I've put the wrong bearings in there.... like a numpty I've put in 6805's and they should be 6805N... which is 6mm deep rathe rthan 7mm and is the cause of all my problems... the good news is that if that works without the wavy washer then as soon as the 6805N's are in there I will be able to space the right hand carrier over to the right with some bottom bracket shims I've ordered, which will hopefully stop the spider fouling on the rear frame as the Brompton folds...

I cleaned the yellow crap off and used proper threadlock after I took them out to tap and face the bracket properly

 

[Graeme_FK]

You need to check the overall width of the BB shell - you can't just junk the wavy washer and assume it'll be OK, because the clip that goes into the RH cup behind the crankset is only designed to limit side to side movement, not eliminate it. In the absence of the wavy washer, any side to side movement that is generated (and there will be some axial force component just through the pedalling action) will be limited solely by the tips of the clip where they emerge through onto the inside of the RH cup. You'll likely get noise and excessive wear and tear.

The wave washer has two functions - it further limits side-to-side motion and it pre-loads the bearings so that unless you have over 5 kgs of directly axial side load on the cranks during pedalling (possible with a very untidy pedalling style but not likely) the chainline will remain stable and the bearings will run at the correct pre-load even after a degree of wear and tear has arisen.

The BB shell needs an overall width of between 67.2 mm and 68.8 mm for the UT system (with the correct bearings in it) to run as designed.

If you had the 7mm wide bearings fitted, did you ditch the retaining c-clip on the RH side? I'd have thought that the inability to fit that into it's groove should have given you an indication you'd done something wrong ...

"That yellow crap" as you refer to it, *is* one of the correct threadlockers for the application on hand. It provides more than enough resistance to thread precession, which is the onlt reason to threadlock at all ... oddly enough, that's why the company that make this kit use it - they don't just put any old gundge on for show.

You *can* use 248 or one of the other low-to-moderate strength materials if it becomes necessary to clean the original material off but the yellow threadlocker that Campag use is perfectly suited for the job.

 

[Tin Pot]

+1

 

[chriscross1966]

Well I've got the right bearings turned up today, along (strangely enough, I had noticed :-)) a C-clip. AS I'll have to pull the bearing cups off again tonight I'll measure the bracket. I rather suspect it is within spec, though I had to face off a lot of paint and thread extrusion I didn't really take any material off below it. I'm using a Pattex equivalent to Loctite 222. Given that this is all happening on a Brompton I fear I'm a long way off-piste as far as normal usage is concerned. My plan is to start off by shimming the out to the maximum allowed width by putting shims between the cup and the bottom bracket on the drive side, simply because I could use more clearance there before I start having to attack the back of the spider to gain clearance when the Brompton folds. Other folks that have done this mod have suggested that you will have to do a lot of fettling to get it right...... if you hunt round for folks messing about with Campy ultratorque BB's you will run across roguemechanic, and while I feel that whatever he's been doing (or was doing) to his means that something went wrong, the effort that he's put in and documented does provide a useful starting point for ideas if you know you are doing something very unusual.... that said he does come across as a bit of a loon, and I'm saying that as a person who has put an Ultratorque in a Brompton and is fitting carbon rims to it as soon as the wheelbuilder orders the right length spokes (sigh)

 

[chriscross1966]

Last night I got the cups off again, along with the by now ruined 6805's (still nicer than the old BB)... A pair of cheap 2RS 6805N's are in there for development purposes. Bracket measured at 67.7mm, wavy washer at a shade over 0.7. Max BB width on Campy's info is 68.8, so without the wavy washer and shimming out the axial float to normal bearing/practice I should be able to stack out the drive side to 1.7-1.8mm. I've put 1.5mm in there and all is well so given that roguemechanic gives figures of a shade over 69.0 mm for his measurements on his experiments then I will look at changing the shim stack up a bit once a pack of 0.3mm shims arrives, if I notice axial slop on the meantime I will put another 0.5 in there and see if I can tighten up the Hirth joint without binding in the bracket. Stacking the drive side cup over 1.5mm has had a massive positive effect on the fouling issue as the bike folds. Hopefully I can get the single ring conversion screws through the lathe this weekend and mod the 60T chainring to suit the spider. Just in time for Warlands to fit the new rear triangle and the 11-speed Alfine wheel they built up yesterday....

 

[chriscross1966]

Now running a 2mm stack and have got a set of homemade chainring nuts in to lower the profile where it was fouling... Working a treat, no knocks, creaks or squeaks, folds without fouling and is a thing of joy.. Picture is of the chainring nuts. Turned down from 16mm hex aluminium to suit the Campy chainring and threaded M6x0.75, the crank mounting is threaded M8x0.75, thankfully have my own lathe so not too hard to do.

Chainring nuts

• chriscross1966
• 8 Jan 2017

 

[chriscross1966]

Visited Henrietta at the LBS where she is having radical surgery to put in an Alfine 11-speed and the good news was that we're not fouling the Kinetics rear triangle that has gone in with the new wheel..... the bad news was that the stadnard Shimano rapidshifter must be the most ugly bicycle component ever... and it's a disgusting shade of silver, so I've ordered a JTEK thumbshifter in black.... lets hope the vostok.bike triangle has the same clearance as the Kinetics one.... and when that goes in I'll swap the mudguards for carbon fibre along with the folding stop disc and the frame clamps....... meanwhile an alloy Campy Mirage compat has turned up to go in the number 2 bike, a mid-nineties short-wheelbase Brompton which is likely to get Sturmey hubs (8-speed plus drum at the back, dynahub+drum at the front)....

 

[chriscross1966]

Fixed now, running nicely with her 11-speed conversion and carbon rear rim