6806-2RS... BB30

S-M

I`m just about to replace my second set of these now on the Boardman, just clocking up 1k miles and the BB30 setup has gone again, this time it appears to be water ingress.

I picked up a couple of 6806-2RS bearings to replace the ones fitted, i had one of my original oem bearings in the garage, so i thought i would see how easy it is to get the seal off the side and have a look inside, with a razor/scraper blade you can pop the seals off easy enough with no damage.

Inside was expected, bone dry and looking rough, i popped the seals off the brand new ones i have bought and to be honest, they did not have much grease in them, a surprisingly little amount.

What i have done with this set is packed them out with the most sticky grease i could find in the garage (which turned out to be CV boot grease) and then i have popped the seals back in place. As expected then bearing is a little more "draggy" but the way the CV grease seams to stick to the car when it has leaked out, leads me to believe it will stay put for a decent amount of time!

What i am wondering is, does anybody make any "higher spec" 6806 bearings, with a better seal fitted? i don't think these 6806 bearings are up to the task of a bottom bracket to be honest

My current BB30 usage has went something like this.

1st OEM set 250 miles, then replaced
2nd set 750 miles

3rd set (packed out with CV grease) will be fitted tomorrow, hopefully lasting longer than 750 miles?

nicklouse

CV grease is not good as it is not really for parts that rotate that much.

a good cycle grease would be better.

and not really.

The Northern Monkey

Just remove the cranks and clean/regrease the bearings every other ride.

Thats what i've been doing and my 2nd set of bearings are fine.

S-M

Do you pop off the bearing covers?


CV joint bearings do some pretty serious rotating!

I am not convinced by "bike grease" that seams to be overpriced for what it is.

supersonic

Lithium grease (which I assume this stuff is) is awful to use for bearings like this - it can rot rubber seals and dries quickly.

Buy teflon fortified grease.

The Northern Monkey

yeah I pack mine with teflon grease.

Haven't resorted to popping off the bearing covers as yet.

nicklouse

S-M wrote:

Do you pop off the bearing covers?


CV joint bearings do some pretty serious rotating!

I am not convinced by "bike grease" that seams to be overpriced for what it is.

they do very little.

which is why some are just rubber X s.

baznav73

You could get some stainless ones.

nicklouse

baznav73 wrote:

You could get some stainless ones.

why?

stainless is a poor bearing material.

S-M

CV grease rots rubber?

I have done 60k on my current car and it's yet to rot the rubber cv boots

You buy a replacement rubber boot kit and they supply you with grease that rots ?

Don't forget that cv joints are not just for turning corners, suspension movement also works them, not many cars seam to have a driveshaft that is fully "inline".

I want a sticky grease that will not wash away when it gets wet, not that bothered about a little extra drag.

S-M

Not convinced that stainless bearings would do anything positive at all.

The problem is that the bearings are kind of open to the elements, the seals are sketchy and the location where they are fitted is not ideal in wet weather, maybe a better bearing shield could be fabric
ated somehow.

supersonic

I said lithium greases can rot rubber seals! And certainly some synthetic seals too as well as making them swell. Lithium greases are poor for bikes and hardly anybody recommends using them. Lithium also has a nasty habit of dry welding metals together just what you don't want in your BB area. Teflon fortified grease is the best all round stuff to use on a bike and around BBs.

Stainless bearings are softer and wear quicker.

S-M

Its is not a lithium grease.

Most CV grease that i am aware of is Moly, every single car i have owned up until the present one has had a cv joint repair at some point and they all have had the same type of grease supplied in the various kits.

I have some lithium grease, its censored and washes away far too easy, this stuff will not wash away, if a CV boot splits on a car and it throws some grease onto the wheel, its a PITA to remove, water will not shift it by itself (i usually use a solvent to remove)

It is going to work perfectly and i am confident i will get all winter from it, no problems at all

nicklouse

S-M wrote:

Don't forget that cv joints are not just for turning corners, suspension movement also works them, not many cars seam to have a driveshaft that is fully "inline".

yes they hardly rotate at all. they mainly slide. the balls do not rotate. they just work like a hinge.

supersonic

S-M wrote:

Its is not a lithium grease.

Most CV grease that i am aware of is Moly, every single car i have owned up until the present one has had a cv joint repair at some point and they all have had the same type of grease supplied in the various kits.

I have some lithium grease, its censored and washes away far too easy, this stuff will not wash away, if a CV boot splits on a car and it throws some grease onto the wheel, its a PITA to remove, water will not shift it by itself (i usually use a solvent to remove)

It is going to work perfectly and i am confident i will get all winter from it, no problems at all

That's fair enough then, many CV greases do contain lithium though.

Neal_

censored are one of the best bearing manufacturers although at £16 each they're not cheap (http://www.akbearings.co.uk/product.asp ... rtRecord=1)

Also you might want to try marine grease to repack the bearings (http://www.morrislubricantsonline.co.uk ... ant+Grease)

S-M

Well i`m just back from a 16 mile ride, that started off with reasonable weather, and then changed into gale force winds, then wind plus rain, and then just as it started hailstoning (WTF?) i got a fooking puncture :evil:

Right at the top of the cliffs on the north east coastline, nobody about, no shelter around, and gale force winds plus hail, brilliant!

I cant feel any difference to be honest with the bearings packed with CV grease, they do feel smoother than the ones i removed :roll: but they dont really feel much difference to my legs, spinning the crank with no chain on is slower as you would expect.

I can remove the cranks at the weekend to see if any of the horrible weather has penetrated the grease.

Perfect little test tbh, the last time i rode in that kind of weather, it killed some bearings when i put the bike away wet (which is what i have done this time on purpose.

pugaltitude

S-M wrote:

What i am wondering is, does anybody make any "higher spec" 6806 bearings, with a better seal fitted? i don't think these 6806 bearings are up to the task of a bottom bracket to be honest

If you need bearings, try your local Brammer www.brammer.biz/
They will supply different quality of bearings from cheap chinese to good quality SKF's.
Can be expensive though.

S-M

I suspect that the main problem with this setup, is that the bearings supplied from any manufacturer simply dont have much grease in them to start with.

I have took apart 3 different makes now, and they dont seam to have much inside, fine for the vast majority of intended use, but utterly censored for a MTB thats getting thrown through water/mud/general censored , in a location that is not ideal.

pugaltitude

Sounds about right with the grease.
If they put a lot of grease in then they would last longer so manufacturers would not sell as much.
My Carrera Fury uses truvativ powerspline BB with cheap bearings and iv gone through 4 BB in 9 months.
My new Trek EX 8 has press fit so maybe something to look out for.

S-M

You could get away with a little grease, if the seals actually sealed!

But they dont!

386ka

They are usually not designed to work in an environment like that. That includes poor seals, and a bit less grease than optimal for bikes. With less grease, they tend to roll a bit easier, but no problems with that on bikes, where there is a lot of torque on the bearing axle.

Chunkers1980

I've heard of Pros using no grease at all, but then hey all they care about is speed, not longevity further than their run/race.

peanstein

in case anyone was interested, FSA has a video that shows how to to maintenance on the sealed bearings.
forward to about 9 min. 30 seconds.
http://www.fullspeedahead.tv/video/7005 ... inteinance

stubs

BB-30 and its SRAM cousin PF30 are a pish poor idea designed so its easier to make a frame and fit the cranks. My Vitus Rapide went through 3 PF30 BBs in about 8 months so I fitted a Praxxis converter and my old SLX cranks.

http://praxiscycles.com/conversion-bb/ So far no creaks the cranks spin better and it all weighs about the same as the PF30. Theres been a lot of good ideas in MTBiking recently but press fit BBs are not one of them.

RockmonkeySC

Bearings should only have a small amount of grease. Too much and a combination of heat expansion and centripetal force will force the seals out and cause water ingress and seal wear.
CV grease is far too heavy for relatively small bearings, its going to cause a build up of heat which will prematurely degrade the grease and seals.
The best thing you can do is get some Koyo bearings (very good quality) and don't touch the seals, just fit them as they are.
I spent a year of a development project on quarry machinery (wet,gritty and dirty) experimenting with bearings to reduce maintenance down time. Nothing we did beat the Koyo bearings.

cycleclinic

Cean and regrase BB30 bearing every other ride wow that requires dedication. Why not sell the BB30 equipped bike and buy something else with BB86 or a threaded BB. The sooner BB30 becomes obsolete the better.

Higher quality bearing will help INA NTN e.t.c are all good but the same will happen again. Loctite can help too. Some of the problems though come with botched installation with a hammer/sockets. a proper bearing press with drifts must be used to prevent damage to the bores and the bearings it self. Some of the home installation method may result in frequent posts on here about poor bearing life but sometimes it is not the fault of the mechanic either, it is the frame and the poor design of this system.

cycleclinic

Cean and regrase BB30 bearing every other ride wow that requires dedication. Why not sell the BB30 equipped bike and buy something else with BB86 or a threaded BB. The sooner BB30 becomes obsolete the better.

Higher quality bearing will help INA NTN e.t.c are all good but the same will happen again. Loctite can help too. Some of the problems though come with botched installation with a hammer/sockets. a proper bearing press with drifts must be used to prevent damage to the bores and the bearings it self. Some of the home installation method may result in frequent posts on here about poor bearing life but sometimes it is not the fault of the mechanic either, it is the frame and the poor design of this system.