Mr Overshoot.
The BB I took apart isn't an early unit. It's off a crank that's just under a year old.
I agree on the lube thing though.
That's why I'm waiting for a King unit and grease adaptor.
Bike Forum
[closed]
Replacement External BB Bearings
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Posted 3 years ago #
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Sorry should have also said anything LX or similar, though I have found some newer XT units with the 6mm bearings?
Perhaps Shimano have dropped back to the 6mm unit as a way of stopping people replacing the bearings?
Posted 3 years ago # -
I had a R/F bb that wents tits up,& coupled with its predecessor,(also a R/F one,that was in the depths of my spares box),I decided rather than just buy a complete new unit,to buy 4 bearings off my local friendly bearing factors,(£40 for 4),& fit 'em myself.
Even though they are good quality SKF bearings,I popped the seals off & was surprised at how little grease was in them,so I packed them with plenty of good quality grease,& hopefully they'll last.Posted 3 years ago # -
The problem with bearings in general is they're manufactured for machinery and high rpm applications therefore the grease can't be overfilled as it needs expansion room etc.
I can't believe no one in the industry has sussed that the basic requirement for our low RPM and mostly wet usage would be extra grease in the buggers in the first place.
Oh and my SSC alike ceramic bearings were found to have seized after about 4 months light but wet use,I managed to free them off but don't hold much hope for their longevity.
I was surprised they'd actually seized tbh as the cranks where stiff to rotate but still spun, it was the top hats that the spindle was rotating in, if they weren't there it'd be metal to metal contact which would happen with the betd bearings and any others that forego the top hat, which'd make a right royal mess of the spindle pretty quickly I should imagine.
Apparently raceface have redesigned there external BB's so they <might> be worth revisiting at some time in the future.
Posted 3 years ago # -
MrOvershoot - Member
Sorry should have also said anything LX or similar, though I have found some newer XT units with the 6mm bearings?
This was a newer XT unit.
I just wish they'd hurry up with the King grease tool.
Posted 3 years ago # -
Even though they are good quality SKF bearings,I popped the seals off & was surprised at how little grease was in them,so I packed them with plenty of good quality grease,& hopefully they'll last.
very good point: I have done likewise with SKF and INA bearings from local (lovely and oooober helpful) bearing shop, as they were going in a hub and suspension pivots respectively. They come with a warning not to riotate faster then so many thousand RPM (arf!) and not a lot of grease so i popped the seals off and filled them up before installing.
How long do we think it will be before shimano move the goalposts and alter cup size/bearing size so you have to bin and replace the whole BB again?
Posted 3 years ago # -
I just wish they'd hurry up with the King grease tool.
Funnily enough, I spent a couple of days last week, riding with a guy on one of those Billy Big Wheels Jones things
He was very enthusiastic about the King BB. He said the tool is quite remarkable. Seems like the way forward once they come out.
Posted 3 years ago # -
I have tapped in a couple of ebay bearings (7mm) a while ago, spent about a fiver for the pair, and they have been going fine for 6 months.
Posted 3 years ago # -
ooh 'what bearings to use until my King BB and the fancy pants tool arrive', my heart bleeds for you Stu.
Posted 3 years ago # -
So, its common knowlege you can change the bearings in a Shimano BB for under a tenner, flip the seals off and pack em with grease for even longer lifespan, could probably do that once in a while and make it last indefinately....
So why on earth spend so much on a King BB that needs almost as much maintenance, from my limited understanding of the king system there is still some dismantleing required before you can attach the grease gun, another 10-15 mins would have the bearings out cleaned greased an re installed.
I guess it will match the headset n hubs nicely though...
Posted 3 years ago # -
tinsy it's something to do with an excuse to spend money on a hobby.
Posted 3 years ago # -
My take on HTII bottom brackets.
The shimano ones last about 12mths for me
My first SS model lasted 6mths then went all wobbly/gritty. Keswick MB's were doing my drivetrain and the nice mechanic actually repacked the BB out with fresh grease and it got to about 14mths without issue before needing replaced. I have since bought another one and packed it out from new. 6mths on its as fresh as a daisy. I may just repack it with grease soon to ensure it keeps going. I have no complaints with the SS ones as long as they are kept greased.Now onto replacement bearings. I have done the replacement SKF & Enduro/Betd bearings thing. Both lasted approx 6mths before going the way of all the others. Repack and you get 12mths. The PROBLEM with these replacement bearings isnt in the lifespan, its in the fact that they do away with the tophats. That tophat protects your crankshaft/whatever from wear when the bearings start to grind/sieze. I noticed that on the aftermarket bearings my lx crankset got a hell of a wear right where the shaft was running on the bearing. Check your cranks!! Not saying its too bad but if i was running the aftermarket ones now i wouldnt risk them getting slightly stiff as they gradually do as this will be grinding metal on metal.
Personally, SS bb with a repack every 6mths is good for me.
Posted 3 years ago # -
Just took my HT11 xt to bits, gonna spend lunchtime in the enginnering dept in the bearing room.....I know they use ceramic bearings too....
Posted 3 years ago # -
Yep, that tophat is there for a reason. Oversize bearings that do away with it are a really bad idea.
Posted 3 years ago # -
3 Shimano XT BBs now all with BETD Enduro bearings. Shimano ones went west rapidly as winter approached - and yes, all BB shells were faced before the BBs were fitted. BETD ones last 3 winters on my SS before needing to be replaced, but did get looked at every 3 months; sorry, but I get an urge to take bikes apart & put them back together again quite regularly, so I never "fit & forget". So, maintenance isn't a chore. At least with the BETD ones you can get at the bearings & reassemble the whole thing easily. IME those tophats just hide the problems.
Posted 3 years ago # -
can you not just run the bb 2mm wider with the standard bearings? yes you lose the clamping area but its not loads is it?
Posted 3 years ago # -
trailmonkey
Funnily enough, I spent a couple of days last week, riding with a guy on one of those Billy Big Wheels Jones things
There's so many of us in the UK now that we can't be avoided.
Scruff.
It's a tough life mate.....
Posted 3 years ago # -
My Phil Wood ones are perfect after around 12 months of riding, so I don't see the point of Kings unless you are trying to help to economy by buying shit you don't need
Posted 3 years ago # -
rich I've had several Phill Woods bearings.
They normaly last me about 18 months.BTW when did need ever come into it.
Posted 3 years ago # -
Indeed.
For some its not about performance, its about what is written on it.Posted 3 years ago # -
And for some it's about trying to find something that lasts longer than 18 months.......
Posted 3 years ago # -
Will a Chris King one do that?
Posted 3 years ago # -
Surely the extra 1mm width makes little difference, that's only 2mm over the entire width of the axle.
Posted 3 years ago # -
I'd say it stands a better chance than most with the grease attachment used regularly
Posted 3 years ago # -
Race Face now make a tool to enable you to service their external bearing BBs. It works on most Shimano & FSA BBs too.
There's a video of it in action here...
Click on the 'LIS' box to see various operations.
Its really fast & easy to use & much cheaper than the Enduro or Phil Wood tools.
Its aimed at bike shops, but give Silverfish a call if you want one.
Posted 3 years ago # -
Apparently raceface have redesigned there external BB's so they <might> be worth revisiting at some time in the future.
Their current BBs use Phil Wood grease which is a lot harder to wash out than regular grease (still don't jet wash them though).
They possibly have a new BB coming out in the near future.
Posted 3 years ago # -
thats not a tool to service as such - its a bearing press to put new bearings into a cup
Posted 3 years ago # -
thats not a tool to service as such - its a bearing press to put new bearings into a cup
& to pull dust covers & old bearings out without damaging them. Thus enabling you to 'service' your bearings & press them back in.
Posted 3 years ago # -
Just got some Hope Big Un bearings (same size) from CRC through the door.
I'll grease em up, drop em in and see how long they last.Posted 3 years ago # -
Has no-one thought about the pleasure of actually using the tool. It's a thing of beauty.
You can get SKF 61805 2rs bearings online delivered for about £22. They fit in my Race Face and 2gn HT11 cups nicely with the top hats. No experience on life span yet as the commuter is being hammer and the real bikes are all tucked up waiting for my attention.
Stu - I'm jealous as always. I got to build a JJ Space frame up on Tuesday night. A thing of beauty.
Tim
Posted 3 years ago # -
I got to build a JJ Space frame up on Tuesday night. A thing of beauty.
Not another one....
BTW the bearing from CRC were 15 squids.
Posted 3 years ago # -
SKF ones? That's cheap if so :O)
Yes, another one. They're common as chalk down here in Sussex!!!!
(I still want one though)
Do you get use to the "sitting IN the frame" style of riding? The front end is very high and it's the first bike I've built where the saddle is inline with the stem. Usually my saddles are above the stem highwise.
Posted 3 years ago # -
I can't find them. Care to do us a linky?
Posted 3 years ago # -
And they are SKF bearings? Cheap if so.
Posted 3 years ago #
Topic Closed
This topic has been closed to new replies.
