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Shimano outboard bearings serviceable?
Posted: Sun Aug 04, 2013 11:17 am
by Ray Young
Does anyone know if Shimano sealed outboard crank bearings are serviceable in any way. I don't think I have put that many miles on mine but they have started to make a noise.
Re: Shimano outboard bearings serviceable?
Posted: Sun Aug 04, 2013 11:55 am
by slarge
Yes and no. They are not meant to be, but if you can (carefully) take the plastic top hat piece out (it is quite brittle so take care) then you can get the seals out of the bearings and give them a clean and regrease. Replacing the bearings I have struggled with as any replacements are 1mm wider, so the top hats don't fit any more (and you need the top hat to close the gap between bearing and crank spindle).
The bearings are press fit (not tight - you can whip them out with a drift and they go back in quite easily) if you want to remove and clean.
Post back up here how you get on - I have about 4 sets that need some TLC and I just keep buying new bearings for £17 or so from Rosebikes or ebay.
People swear by Hope bearings, but at £65 a set I am happy to let them swear!
Re: Shimano outboard bearings serviceable?
Posted: Sun Aug 04, 2013 1:24 pm
by Ian
Phil Wood bearings are also worth a look, and come with their own top hats.
I actually have a proper Phil Wood tool to taking bearings out which simplifies the process, but since switching back to square taper, its just sat on the shelf doing nothing
One of the reasons often cited for premature bearing failure is that the BB shell isn't squared off properly (i.e. both outer surfaces must be exactly parallel). While I can appreciate this would contribute to wear, I think that the more exposed nature of the bearings doesn't help :?
Re: Shimano outboard bearings serviceable?
Posted: Sun Aug 04, 2013 5:52 pm
by Ray Young
Ian, why the switch back to square taper?
Re: Shimano outboard bearings serviceable?
Posted: Sun Aug 04, 2013 5:59 pm
by Bearbonesnorm
Ian, why the switch back to square taper?
because everything since has been poor show!
Re: Shimano outboard bearings serviceable?
Posted: Sun Aug 04, 2013 6:44 pm
by Ian
s8tannorm wrote:Ian, why the switch back to square taper?
because everything since has been poor show!
:D
That and square taper bb's cost less than £20 and give nearly two years of trouble free riding (for me) before needing replacement.
Also at the time I didn't much like the offerings from other crank manufacturers and Middleburn didn't do an out board option.
Re: Shimano outboard bearings serviceable?
Posted: Sun Aug 04, 2013 11:06 pm
by Zippy
I've been thus far relatively impressed with my tapered roller bearing hollowtech BB for longevity.
But yes, square taper definately last longer!
Re: Shimano outboard bearings serviceable?
Posted: Mon Aug 05, 2013 9:41 am
by Cheeky Monkey
slarge wrote:People swear by Hope bearings, but at £65 a set I am happy to let them swear!
I think you might have missed the point. With a Hope BB you can, unlike Shimano, replace the sealed bearings. The cups and spacer are re-used. I can't recall if they're common type or you have to buy the ones Hope sell (I think it's the former) but they're rather less than £65.
I appreciate that with some canny shopping you might be able to buy a whole Shimano BB for something like the cost of Hope's replacement bearings but I just prefer the fact that I can re-use it.
I had fun telling a mate this after he threw a Hope BB away after the first set of bearings wore out
Re: Shimano outboard bearings serviceable?
Posted: Mon Aug 05, 2013 11:12 am
by Bearbonesnorm
I can't recall if they're common type or you have to buy the ones Hope sell (I think it's the former) but they're rather less than £65.
Hope had their own bearings made. One of the main issues with outboard BB is the fact that there's no standard bearing available with the required OD / ID hence the stupid plastic top hats that everyone else uses to sleeve the ID to the required size.
Stainless bearings are about £30 a set BTW.
Re: Shimano outboard bearings serviceable?
Posted: Mon Aug 05, 2013 12:57 pm
by ScotRoutes
Re: Shimano outboard bearings serviceable?
Posted: Mon Aug 05, 2013 1:27 pm
by Cheeky Monkey
and at least £7 for delivery 8-)
Re: Shimano outboard bearings serviceable?
Posted: Wed Aug 14, 2013 8:30 pm
by Ray Young
Well I eventually managed to take a break from decorating and got round to trying to service my "do not disassemble " shimano xt bearings and basically it's a piece of cake. After removing them from the bike and wiping away any crap with a rag I gently prized off the t cap followed by the seal using a very thin bladed screwdriver, the type used for screws in spectacles. I then wiped clean and re greased them before putting them back together. I did try to use a drift to get them out completely but they wouldn't budge. The t cap on the drive side came out no bother but on the other side I managed to snap off a bit off the lip but not so much that it was unusable. Whilst I had everything apart I noticed the plastic tension screw thing had a crack running half way round it, probably my fault from over tightening it at some point, but put it back in anyway and tightened it gently. The cranks now run silently. I had said that I didn't think I had put many miles on them but they had had a few submersions at stream crossings which is what I'd figured was causing the problem. Job done, money saved :D .
Re: Shimano outboard bearings serviceable?
Posted: Thu Aug 15, 2013 9:41 am
by Zippy
I remember my BB bearings siezing fairly solid, I flushed them through with WD40/GT85, hit the cranks a few times and they started rotating again. Now this was sub optimal as no grease in there and the bearings were a bit spinny/sounding rough, but hey, they carried on working for a while which saved me some much needed student money! - Note, I did have to ride the bike pretty much most days to keep the bearings spinning.
Re: Shimano outboard bearings serviceable?
Posted: Thu Aug 15, 2013 11:36 am
by jameso
I won't use Shimano BBs anymore, they're just junk.. don't last long and are one of my pet-hate products, particularly since Shimano stuff is generally so good. You can pop the bearings open to regrease but it's futile, the sealing is simply inadequate. The new XTR is intended to be better sealed so that may be worth a look, but this one caught my eye as it's got replaceable bearings at a reasonable price.
http://www.evanscycles.com/products/pra ... t-ec049756 No idea of durability/quality but Praxis seem to have a good rep, will be trying one out very soon.
Re: Shimano outboard bearings serviceable?
Posted: Thu Aug 15, 2013 12:03 pm
by Bearbonesnorm
Obviously the ability to change bearings is a good thing ... but it still uses bearings with a 25mm I/D to support a spindle with a 24mm O/D, so still needs the stupid plastic top hat shims ... which as Ray's just discovered can be a PITA to remove without breaking them. From an engineering point of view a 0.5mm plastic shim used on a heavily loaded (think about standing up rather than the action of pedaling) axle that's subjected to water, grit, etc is borderline madness
Re: Shimano outboard bearings serviceable?
Posted: Thu Aug 15, 2013 12:11 pm
by Zippy
s8tannorm wrote:
Obviously the ability to change bearings is a good thing ... but it still uses bearings with a 25mm I/D to support a spindle with a 24mm O/D, so still needs the stupid plastic top hat shims ... which as Ray's just discovered can be a PITA to remove without breaking them. From an engineering point of view a 0.5mm plastic shim used on a heavily loaded (think about standing up rather than the action of pedaling) axle that's subjected to water, grit, etc is borderline madness
That's why I'm currently trying out one of these:
http://superstar.tibolts.co.uk/product_ ... cts_id=353
ired of poor lifespan hollowtech 2 bottom brackets? Try our SuperHD replacement using oversized taper roller bearings for a rebuildable/maintainable/super heavy duty performance.
Patented taper roller bearings are over 400% larger than normal HT2 type deep groove bearings, and are not far off the size used in car rear stub axles. Taper bearings are used in headsets to allow for sideloads on installation and in use, so we packaged this system for BB use. This solves the main cause of HT2 early death, and the easy maintinence solves the other problem of seized bearings. If it can cope with 400kg of weight per wheel on a car, then it sure as well can cope with anything you throw at it!
5 YEAR WARRANTY on this part as only neglect will kill it off. If it gets packed with mud or water then pop out the bearing and lip seal, scrub clean and regrease. Simple, sturdy and long lasting. Look after it and it will keep you rolling for years.
Double seal internally
Deep lip seal for durability
4x3.8mm taper roller bearings (most HT2 type only have 3mm spherical ball bearings)
Rebuildable for long term reliability
125 grams
Seems to be working alright at the moment; doing about 100 miles a week on it, but I did change it around spring time, winter commuting will be the real test.
As they're tapered roller bearings, any slack can just be tightened up
Re: Shimano outboard bearings serviceable?
Posted: Thu Aug 15, 2013 1:47 pm
by jameso
Superstar bearing looks good, not seen that before.
On top hats, only Shimanos are a real pita to remove ime, FSA and RF seem to come out easier. I'm not sure which is worse, the plastic spacer or the direct bearing to axle fit. Considering the loads and tolerances as well as my intolerance of washing bikes and creaky drivetrains, I'd go with the spacer - it's like PF30 vs BB30?
I got a King for one bike to be sure as poss of BBs not giving me any grief, that uses a shim spacer on the axle although its a better design than the usual hat bush.
Re: Shimano outboard bearings serviceable?
Posted: Thu Aug 15, 2013 4:18 pm
by ScotRoutes
Raceface?
You can get a BB service kit (bearing plus shims)
http://www.chainreactioncycles.com/race ... -prod64642
Re: Shimano outboard bearings serviceable?
Posted: Thu Aug 15, 2013 4:30 pm
by Zippy
Got race face BB's for my pressfit bottom brackets as at the time when press fit was the new standard and I needed a new BB, shimano or race face was the only option, and with race face I could actually change the bearings as opposed to have to use a big hammer near my carbon frame :?
Glad to see you can actually buy the raplacement bearings now
Re: Shimano outboard bearings serviceable?
Posted: Sun Aug 18, 2013 1:15 am
by FLV
As has been said, re greasing the shimano ones works briefly.
I have excellent success with hope bb's for normal external £60 for the unit to start with then I only replaced the bearings after about 2 years!
My pf30 bike currently has a KCNC pf30 / 24mm convertor bb in it which is going well so far. It looks like the bearings can be replaced with items from enduro which have a reputation for being good.
Edit. Looks like it can be done BETD offer an upgrade
http://www.mountainbikecomponents.co.uk ... ng+upgrade
Re: Shimano outboard bearings serviceable?
Posted: Mon Oct 07, 2013 10:31 pm
by Ray Young
FLV wrote:As has been said, re greasing the shimano ones works briefly.
Well after nearly 8 weeks of using my "serviced" shimano bearings they have started to make a noise again so I've done what Ian did and gone back to square taper. Luckily I didn't sell the BB fitted to the bike when I bought it new so it should see me good for a couple of years at least if not more.