Alternative to TA Axix BB

[Mrs Pingu]

Potentially calling Paul Smith to the courtesy phone please 
(Or indeed anyone else who knows what they're talking about)

I'm sick of the noise coming from my Axix BB. I did replace the bearings a couple of years ago but the cups kept unscrewing themselves and it still makes that flipping noise. At home it's not so bad, but the thought of listening to it on 15km long climbs on holiday is not a happy one.

Anyway... I've read this http://www.plsmith.co.uk/ta-carmina-chainset-review and various other threads here and if I understand it, it seems like I probably need a Shimano JIS BB to put my TA Carmina cranks on.

So how do I go about this? Presumably for starters I need to measure the length of the current BB? Then what, do I just get the same length in a Shimano or is it more complicated than that? What model do I need?
Anything else I need to know or find out?

TIA 

[rogerzilla]

Measure one side at the narrow end of the taper.  JIS is about 12.7mm.  ISO is smaller.  TA have used both!

Assuming it's JIS, get a Shimano UN55 or Tange Seiki of the same length.  The Tanges can be had with hollow axles.  Most BBs you see will be symmetrical these days, like the Axix.

Tapers on cranks and BBs often deviate from the supposed standard so chainline may not be exactly the same but this will get you close.

[Mrs Pingu]

Right then. The small end of the taper was 12.7mm which suggests JIS. The length of the taper from the shoulder was 18.9mm.
The axle is 116mm.

As far as I can see the UN55 comes in 115 or 118mm spindle length. Which one should I go for?

[mcshroom]

Do you have a few mm space between the inner ring and the frame? If so, I'd go for the 115mm one. Both would probably work, as you are only talking about moving the chainline in 0.5mm or out 1mm

[Mrs Pingu]

Ach they're cheap. I'll order one of each and hopefully head frustration off at the pass.
(Famous last words...)

[Brucey]

IIRC in UN55 both 115 and 118mm units are almost symmetric and give chainlines that differ by about 1.6mm.  A 113mm UN55 is more heavily asymmetric and gives almost the same chainline as a 115mm unit.

cheers

[Mrs Pingu]

I've fitted the 115mm. It didn't leave the inner ring fouling the frame so I'll take it out for a quick run round the block when it's not pishing with rain.

[Mrs Pingu]

No creaks today. No fettling required. I just whacked it in and put the cranks on, didn't even need to twiddle the limit screws.
Daren't do any DIY til the heat death of the universe now cos I think I've just used up all my fettling karma.

[Brucey]

what are the chances of that happening...?   

cheers

[Mrs Pingu]

Exacerly

[CommuteTooFar]

... but the cups kept unscrewing themselves ...

Use a weak threadlock.  Whatever you do not use a strong one.  Weak threadlock is sometime called anti-shake.

Maybe another assembly compound such as copperslip will hold the cups in place.

I am not an expert on this I am sure one the engineering types could suggest a suitable substance.

---

I gave up on TA Axix because the bearings were too difficult to get out of the cups,
I bought a Royce cartridge BB instead,

[Mrs Pingu]

I did use threadlock. Didn't stop the creaking though.

[eckagain]

I did use threadlock. Didn't stop the creaking though.

Mrs P, maybe try PTFE tape  wound round the threads a couple of times? That cured creaking on the BB on my ti frame.

[CommuteTooFar]

You probably have over cut bottom bracket shell. It could be sleeved and re-threaded more tightly. Alternately your favourite frame builder could replace the bottom bracket shell.

[rogerzilla]

Funnily enough, I've just replaced the Axix on the track bike with a Token sealed unit (12g lighter!). I'd replaced the bearings in the Axix but they didn't take kindly to my stomping, most of the grease spewed out and the cranks became noticeably stiff to turn.  I am rather hard on BBs.

I might put better bearings on (the TA originals lasted a couple of season's TTing, although they were rough towards the end) and try it again, as the singlespeed has a Genetic Karyotype of the same length which is frankly shite: the LH cup cannot be securely tightened without compressing the bearings*.  It's all very well having a carbon sleeve but if that compresses easily, it's a waste of time.  The Token is a similar design but is better specified and actually works.

*this is a feature of the Axix too, but that has a lockring so the LH cup doesn't have to be tight.