Bottom bracket woes

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Rabbit
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Joined: 19 Aug 2012, 10:43pm
Location: The New Forest

Bottom bracket woes

Postby Rabbit » 6 Jul 2015, 9:18pm

Last year I bought a new Campagnolo record bottom bracket (the cup and cone type) for a vintage rebuild, and carefully installed it (at least I thought I did!) Made sure there was no play on the cranks but also not too tight that it didn't turn smoothly. After a year running on the bike with about 200 miles a week during the summer and no real winter riding I took it off to find - aaaargh - red, rusty grease on the drive side, bearings tarnished and horrible black marks and pitting on the cup and cone. The non drive side also marked but not as bad. Apart from the fact I have no idea how water got in to the unit what have I done wrong? I was expecting years of use from the bottom bracket and although it does still turn pretty smoothly it's clearly more worn than it should be. Any advice so I don't repeat the same mistake, whatever it was, next time? Perhaps my adjustment was off after all...

mercalia
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Joined: 22 Sep 2013, 10:03pm
Location: london South

Re: Bottom bracket woes

Postby mercalia » 6 Jul 2015, 9:25pm

Left out in the rain and ran down the seat pin?

Rabbit
Posts: 272
Joined: 19 Aug 2012, 10:43pm
Location: The New Forest

Re: Bottom bracket woes

Postby Rabbit » 6 Jul 2015, 9:32pm

No, not left out but it was ridden a few times in the rain, I wouldn't have thought much would have got down the seat pin would it? That said it is one of those strange fluted pins, but if you're sitting on it how much rain can really get down there???

fastpedaller
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Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Bottom bracket woes

Postby fastpedaller » 6 Jul 2015, 10:25pm

Rabbit wrote:No, not left out but it was ridden a few times in the rain, I wouldn't have thought much would have got down the seat pin would it? That said it is one of those strange fluted pins, but if you're sitting on it how much rain can really get down there???


If you have no mudguards, maybe quite a lot? I remember the old Campag bb cups having a 'thread' shape (for want of a better expression) on the axle hole - the idea was that the water was thrown outwards by the rotation of the axle - that was back in 70's/80's, so maybe not the design of yours?

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Bottom bracket woes

Postby Brucey » 6 Jul 2015, 10:31pm

Rabbit wrote: ...it was ridden a few times in the rain ....


I've done tens of thousands of miles on BBs of this type and they only get that way, that quickly, if water gets inside.

If you think this is at all likely (and unless you ride only in the dry, it is...) then you need to use a super quality grease which is loaded up with corrosion inhibitors. Even then you still need to strip and regrease regularly, or fit and use a grease nipple.

BTW if you are one of these 'car wheel bearing grease will be fine' merchants, that won't help either.

One wet ride in the winter (with road salt about) can kill one of these BBs.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

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kylecycler
Posts: 662
Joined: 12 Aug 2013, 4:09pm
Location: Kyle, Ayrshire

Re: Bottom bracket woes

Postby kylecycler » 6 Jul 2015, 11:50pm

I guess water has got in down the flutes in your seat pin, either that or via vent holes in the chainstays (unless they've been plugged*), even when you've washed the bike, especially if you've used high pressure. I've heard that the legendary Connecticut framebuilder Peter Weigle, who you might know markets 'JP Weigle's Framesaver' anti-corrosion spray, drills a hole under the bottom bracket shell of all the frames he builds; he plugs the hole with a Presta valve cap before he goes out on a wet ride then reaches underneath and pulls the 'plug' out when he gets back.

On a more mundane level, the Argos catalogue Vertigo BSO I bought when I went back to cycling in 2009 had the same problem, even with a Shimano cartridge bottom bracket I'd replaced the original cup and cone BB with, when my flat got re-plumbed and I connected the hose to a tap connected to the mains water supply instead of the water tank in the attic and merrily blasted water into the bottom bracket shell and the grease out of the wheel bearings and freewheel. You live and learn.

*There was a framebuilder in Hawaii, James Morikawa, who tried filling the frame tubes with Argon gas (the gas used for TIG welding), which is inert, then plugging the vent holes with brazing rod. Hawaii, although it's hot, is notoriously humid and lethal for corrosion. The idea didn't really work, though, and he figured it was better to leave the vent holes unplugged to let the air circulate (vent holes have to be drilled before brazing or welding to prevent gas blowback (I think - I'm not a brazer or a welder)).
http://modikoso.com/nav/documents/frame ... eTubes.htm

Incidentally - Brucey - you mentioned in your thread about your fork that failed on you that it's possible to pressure-test frames for cracks**. Well, that builder did just that...
http://modikoso.com/nav/documents/frame ... Leaks.html

I don't think James Morikawa still builds frames, which is a shame because he was a good lad, but it's worth reading through the other links on the site.

**Porsche did exactly that with their race car spaceframes...
https://www.youtube.com/watch?v=0C5dLpDPk9c

Just imagine the work involved in restoring that frame, let alone the rest of the 917, compared to a bicycle! But you'll see the surface table is just a far larger version of the surface plate in a bicycle framebuilder's workshop. According to Brian Redman, one of Porsche's works drivers, if the pressure gauge showed a loss of pressure, the mechanics would go around the frame with cigarette lighters and when the flame flickered they'd found the crack. I suppose the alternative would have been to dunk it in a swimming pool, Brian Jones style, and watch for the bubbles... :)

Rabbit
Posts: 272
Joined: 19 Aug 2012, 10:43pm
Location: The New Forest

Re: Bottom bracket woes

Postby Rabbit » 8 Jul 2015, 8:30pm

Thanks all - just on the question of grease, I used a proper cycle bearing grease (Juice I think it was called, very sticky stuff) but maybe it's not as good as it should be. What do you recommendation Brucey for a grease with corrosion inhibitors? As you say, you live and learn - I think in future I will check more often and not leave it until the end of the year! Thanks...

pwa
Posts: 11254
Joined: 2 Oct 2011, 8:55pm

Re: Bottom bracket woes

Postby pwa » 8 Jul 2015, 8:45pm

Aren't the flutes in the seat pin supposed to stop above the point where it enters the frame? The portion inside the frame should be cylindrical.

Brucey
Posts: 36763
Joined: 4 Jan 2012, 6:25pm

Re: Bottom bracket woes

Postby Brucey » 9 Jul 2015, 7:51am

Rabbit wrote:Thanks all - just on the question of grease, I used a proper cycle bearing grease (Juice I think it was called, very sticky stuff) but maybe it's not as good as it should be. What do you recommendation Brucey for a grease with corrosion inhibitors? As you say, you live and learn - I think in future I will check more often and not leave it until the end of the year! Thanks...


I have not used juice lubes but if they contain an adequate amount of corrosion inhibitors for this service I should be very surprised.

I've had good results using Castrol SBX grease. This grease is specifically designed for slow moving, highly loaded bearings which are exposed to corrosive conditions.... sound familiar? I've got enough of this to last me years... however when I contacted Castrol UK about getting some more of this (for others), they said 'we don't do that any more' and pointed me to a product that seemed like it wouldn't be as good. Castrol still sell SBX in other markets... but just can't be bothered to bring it into the UK any more.... :roll:

Re water getting past the seat post; this is quite likely to occur if the seat post is even slightly undersize in the frame. As a test, if you slacken the binder bolt and the seat pin can then wobble in the frame appreciably, there must be a tiny gap through which water may find its way. Often reaming the frame lightly and going up 0.2mm on seat pin size will fix it, but occasionally a seat pin must be machined to fit precisely in the frame instead.

BTW if water had come down the seat tube I suspect that there would be other signs that this had happened.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

pliptrot
Posts: 570
Joined: 12 Jan 2007, 2:50am

Re: Bottom bracket woes

Postby pliptrot » 10 Jul 2015, 12:08pm

I had something similar happen to me with a more recent Campag BB (sealed bearings) recently. Someone suggested this was moisture ingress along with expansion/contraction of air in the frame. As the bike has lived in the tropics and now Northern Europe it has seen enough sudden changes in temperature and humidity without problem to preclude such a theory: no, what did for this was a very wet ride a few months before the creak set in (and thus made me look for problems). Having seen similar things with Campag hubs I conclude that Campag aren't really interested in weather-proofing their equipment. If you look at their advice for chain maintenance (don't remove or degrease, just wipe now and then) you get the idea of their target market; Italian or Californian enthusiasts who don't see much in the way of foul weather. So water-proof grease, lots of it and changed frequently, is the way to go. Sad, and rather curious.

MikeF
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Joined: 11 Nov 2012, 9:24am
Location: On the borders of the four South East Counties

Re: Bottom bracket woes

Postby MikeF » 10 Jul 2015, 6:38pm

On fluted seat posts I've liberally coated the flute seat post join with Waxoyl. When it dries it leaves a coating of wax which seals the gaps. The Waxoyl I've used is old, but I presume the modern stuff is the same.

On bearings such as BB I've used Duckhams Keenol, now no longer made. Gruebb seems to be making suitable replacement called Ramanol. http://www.marathonleisure.co.uk/shopimages/Ramonol%20Using%20the%20right%20grease%20is%20important.pdf
http://www.gruebb.com/
"It takes a genius to spot the obvious" - my old physics master

LWaB
Posts: 121
Joined: 26 Nov 2010, 5:33am

Re: Bottom bracket woes

Postby LWaB » 11 Jul 2015, 3:34am

Did you use the plastic shield between the BB cups? In combination with plenty of good grease and a drainhole in the bottom of the BB shell, I've found good cup and cone BBs to last for many years.