Shimano Hollowtech ii BB bearing knackered after just 3500 miles

ben-----

Quite annoyed with myself as I guess this is my fault. A bottom bracket bearing should last more than 3500 miles right? Obviously I did something wrong. NDS bearing is gratey, clearly needs replacing. It's a Shimano BB-R60 Ultegra 6800/105 5800 Hollowtech ii Black/Grey English Thread BB. It's been used in quite a bit of wet recently, that's what's done it I guess. But it should last a lot longer than that, right? (My crappy old bike I had for more than 10 years, never touched the BB and it was fine, that was before I was cycling as much as I am now, but anyway). What did I do wrong? Not keep regreasing it? Not have the crank done up tight enough? Not have the set up / spacers right? There's only one spacer on that, it's on the NDS and it looks like so…



I've got it so that the side that's showing in the left photo is facing outwards, away from the bike.

I'm imagining that for some reason the way I had it didn't stop water getting in. Is that right would you think? And how to counter that? Thanks.

sungod

wiggle sells them for under a tenner, if you look at the reviews giving low ratings several complain about short life, overall ratings are high, but if most reviews were made after a short period any long term issue wouldn't be reflected

the shimano blurb says "...seal design has minimal bearing interface", which sounds like the seals may not be especially sealy

perhaps the nds seal was a bit iffy and water/dirt gradually replaced the grease?

is water getting at it from the rear? i.e. entering the frame somewhere and draining into the bb area, check if the inside of the bb shell is muddy/damp - some bikes have a drain hole, these can get clogged, some bikes have no drain hole - water pooled in the bb shell has a long time to cause trouble

mac9091

Things aren't made to last long anymore. That said they are easier and quicker to replace (albeit slightly) than the older square tapered ones.

Bobbinogs

I get through an Ultegra BB set about once a year and it has been that way for a few years now. I get about 7,000 miles out of that bike though so a little more than what you have.

Some factors that may influence bearing life include having a decent front mudguard when riding on wet roads. Also, avoid pressure washers or directing a hose at the BB seals when cleaning. If you go through flooded roads then try and avoid pedalling when the BB is submerged, easier said than done sometimes but the added bonus is that your shoes don't fill up :-)

KINGGARY

That's about how long mine lasted on my winter bike, the left hand side devolved play.
I was a little disappointed but when I realised they were only £10 and took about 20 minutes to fit.
I did look at hope/Chris king but realised I would probably need to replace the shimano one around 6 times to make the cost viable, by which time I'll have changed the bike !

Bordersroadie

A front mudguard and long flap will lengthen the life of a bottom bracket massively on a wet weather bike, not sure if the op has either fitted but even on a winter bike thus equipped and ridden in lots of foul weather I'd expect much more mileage than mentioned.

rubertoe

Shimano Hollowtech bbs are made of cheese.

ben-----

sungod wrote:

wiggle sells them for under a tenner, if you look at the reviews giving low ratings several complain about short life, overall ratings are high, but if most reviews were made after a short period any long term issue wouldn't be reflected

Right, I bought a replacement from Wiggle just before posting my comment. Didn't look at the reviews. They're not always that cheap from Wiggle though. The one that's just failed also cost £10 - from Merlin in mid Nov last year. At that time from Wiggle they were, can't remember, 15 or more.

the shimano blurb says "...seal design has minimal bearing interface", which sounds like the seals may not be especially sealy

I wonder if using some sort of sealant, silicone?, the kind of thing you use in bathrooms between walls and sinks, would be a good idea? Might give that a go.

perhaps the nds seal was a bit iffy and water/dirt gradually replaced the grease?

Possibly. I do wonder if it was tight enough, compressed together enough, along the line of the spindle. Dunno.

is water getting at it from the rear? i.e. entering the frame somewhere and draining into the bb area, check if the inside of the bb shell is muddy/damp - some bikes have a drain hole, these can get clogged, some bikes have no drain hole - water pooled in the bb shell has a long time to cause trouble

No idea, I'll have a look. It's a Van Nicholas Yukon frame. I think there were water droplets on the BB shell though, so that could be something. I'll look into that, thanks.

Bobbinogs wrote:

Some factors that may influence bearing life include having a decent front mudguard when riding on wet roads. Also, avoid pressure washers or directing a hose at the BB seals when cleaning. If you go through flooded roads then try and avoid pedalling when the BB is submerged, easier said than done sometimes but the added bonus is that your shoes don't fill up

I have mudguards: SKS Chromoplastic, but no flap. I'll look into that. I think I've got one. Yeah my feet have been soaking recently.

I'll find a flap for the front mudguard. Definitely a good idea that. And I'll take it apart again and take the shell out this time to see if it's apparent if water is getting into the frame as suggested. And I'm going to see if there's any sealant lying around anywhere and give that a go on the new BB when I put that in. Thanks all.

k-dog

Facing the bb shell made a big difference to me - I went through a couple a bit quick and then had that done and I've not replaced it since - only about 5,000 miles but still fine.

ben-----

"Facing the bb shell" - what do you mean by that? Don't know what that means. Thanks.

k-dog

You need a special tool which cuts the outside edges of the shell so they are totally parallel - it should really be done to all frames using a BB with something which presses against the outside edge. It just shaves off a tiny bit of paint/metal so bearings are properly lined up.

Expensive tool so I had it done at my LBS for £10.

ben-----

oops

ben-----

k-dog wrote:

You need a special tool which cuts the outside edges of the shell so they are totally parallel - it should really be done to all frames using a BB with something which presses against the outside edge. It just shaves off a tiny bit of paint/metal so bearings are properly lined up.

Expensive tool so I had it done at my LBS for £10.

I see. Thanks.

Nick Payne

ben----- wrote:

"Facing the bb shell" - what do you mean by that? Don't know what that means. Thanks.

The park Tool website has a good description with photos of the process: http://www.parktool.com/blog/repair-help/bottom-bracket-tapping-threading-chasing-and-facing

However, the tool to do the job costs several hundred pounds, so find a competent nearby bike shop that can do it for you. If you have external BB bearings that rely on the face of the BB shell for their alignment, then getting the shell faced will ensure that the bearings are accurately parallel to each other and square to the crank axle.

Most manufacturers don't machine frames after they have been welded/brazed, so distortions introduced in manufacturing aren't corrected. Here's a couple of photos I took a while ago part way through the process of facing the BB shell on a rather expensive custom titanium frame. I had to remove 0.2-0.3mm from each side of the BB shell to get a complete cut all the way round so that the external BB bearings would be aligned. You can see, from the part of the face that the cutters hadn't yet touched, that the welding of the frame had made the front side of the BB shell wider than the rear.

Alex99

sungod wrote:

wiggle sells them for under a tenner, if you look at the reviews giving low ratings several complain about short life, overall ratings are high, but if most reviews were made after a short period any long term issue wouldn't be reflected

the shimano blurb says "...seal design has minimal bearing interface", which sounds like the seals may not be especially sealy

perhaps the nds seal was a bit iffy and water/dirt gradually replaced the grease?

is water getting at it from the rear? i.e. entering the frame somewhere and draining into the bb area, check if the inside of the bb shell is muddy/damp - some bikes have a drain hole, these can get clogged, some bikes have no drain hole - water pooled in the bb shell has a long time to cause trouble

Mine has a drain hole, but there always seems to be some water inside the plastic sleeve whenever I open it up. They're just not sealed very well. I reckon on about a year for a 6800 BB.

ben-----

There was a quite a bit of water inside the plastic tube which goes between the two bearing housing on either side. Wasn't clear how the water was getting there though. Nothing made it appear that it was getting there from the frame like suggested by sungod but I couldn't really tell. It was mainly, if not entirely, inside the plastic tube not outside; outside being where it'd be if it'd arrived there from within the frame.

> I reckon on about a year for a 6800 BB.

Right but time isn't that much use really. Distance, because obviously it depends how much its used.

Thanks.

keef66

Apart from having the BB shell faced, making sure it doesn't have water sitting in there, and never pressure-washing it, there's not a lot else you can do to prolong the life of a Hollowtech BB. (I'm assuming from your pics that you have a triple chainset; usually there's no spacers for a road double) Silicone sealant would be a really bad idea.

Forgive me if you know this already, but it may help somebody else doing it for the first time:

When replacing a Hollowtech BB:

Loosen the 2 pinch bolts securing the non drive side crank. If you remove them completely, make sure you retrieve their washers, and the plastic safety tab from the gap in the crank
Unscrew and remove the (usually plastic) preload cap from the end of the spindle, and slide the crank off.
Drop the chain off the inner chainring and sit it on the BB shell
Withdraw the chainset from the drive side. You might have to persuade it; if so, protect the end of the spindle with a block of wood or use a plastic faced mallet.
Remove the old BB cups using a tightly fitting BB tool. This can be quite tough; I usually do it with the bike on the ground, not wobbling about in a workstand. Remember the drive side cup unscrews clockwise!
Clean up the threads and if the BB shell is full of water/ sludge, investigate where it's getting in and consider a drain hole. This is the time to have the BB shell faced if you want. Actually if the LBS is facing it for you, you may as well get them to do the whole thing.
Back to the DIY job: apply some grease or copperslip to the nicely cleaned threads and install the new BB cups. Fingers only to get them started without cross-threading, installing the plastic spacer tube with the first one. Again, remember the drive side tightens anticlockwise, so don't mix them up. Tighten them fully, again with a tight fitting BB tool.
Make sure the chain is still sitting on the BB shell before reinstalling the chainset.
Lightly grease the inside of the bearings and the outside of the spindle and then reinstall the chainset. Again, some gentle persuasion may be required.
Refit your spacer, then lightly grease the splines on the spindle and refit the crank arm.
Screw the preload cap in to the end of the spindle, only finger tight (Shimano do a little tool to fit the preload cap for about £3, or many BB tools include one) This applies a small preload to the bearings.
Reinstall the 2 pinch bolts with their washers and the plastic safety tab, the pin of which should sit in a hole in the spindle
Tighten the 2 bolts alternately till both are equally tight. This is what holds the crank on.
Sit the chain back on the inner chairing and off you go!

keef66

ben----- wrote:

There was a quite a bit of water inside the plastic tube which goes between the two bearing housing on either side. Wasn't clear how the water was getting there though. Nothing made it appear that it was getting there from the frame like suggested by sungod but I couldn't really tell. It was mainly, if not entirely, inside the plastic tube not outside; outside being where it'd be if it'd arrived there from within the frame.

Only way it could get in there would be between the spindle and the bearing. As above; all you can do is adequately grease when assembling and not blast water at the BB when washing. I whip out my Shimano chainsets at least once a year for a quick check, and reassemble with a generous dollop of grease. Pretty reliable so far...

Lurking on here I still get the impression that Shimano BBs are a bit more reliable than FSA and SRAM.

crankycrank

Also make sure your BB shell has a drain hole at the bottom. I've noticed that BB shells often don't have drain holes anymore. It used to be standard on steel frames. I have never understood why all frames don't have drain holes as you can kill any BB in no time if it's sitting in a pool of water that collects in the shell. If you don't have a drain hole you can just drill your own. It's not rocket science but if you feel uncomfortable doing this take it to someone who has the knowledge to do it properly.

ben-----

keef66 wrote:

Screw the preload cap in to the end of the spindle, only finger tight (Shimano do a little tool to fit the preload cap for about £3, or many BB tools include one) This applies a small preload to the bearings.

One thing that worries me is that the two parts of the crankset aren't pushed together enough - which would then mean there's a gap exposing bearings to elements. So why is "only finger tight" so important on end of spindle crank bolt? I want to ensure that the two part are each pushed towards the middle of the bike.

Only way it could get in there would be between the spindle and the bearing.

sungod was talking about the possibility of it getting there via the inside of the frame, which seems quite possible also. But from what I could tell (not that much) that isn't where it was getting in in my case. But I really couldn't tell properly.

Lurking on here I still get the impression that Shimano BBs are a bit more reliable than FSA and SRAM.

They're clearly a bad design from a lasting point of view though. The crappy bike I referred to is a Specialized Epic, god knows what kind/make its bottom bracket is. Since I've been more seriously into cycling, therefore cycling more and using a GPS thing, which was about 3 years ago, it's done 12000 miles. And a lot of those were in very wet and muddy conditions. But then I had and used the bike for more than 10 years before that as well. Didn't look after it very well. Never touched the BB apart from tipping some oil into it once in a blue moon. Nothing wrong with it so far as I know. And a Shimano Hollowtech lasts less than four months.

crankycrank wrote:

If you don't have a drain hole you can just drill your own. It's not rocket science but if you feel uncomfortable doing this take it to someone who has the knowledge to do it properly.

That sounds like a possibly good idea. The water would just go in between the shell and frame though?; Maybe that's better than in the BB shell. Might give that a go. Wouldn't make things worse I wouldn't have thought. Maybe better.

Thanks.

keef66

Some of the older style square taper or splined cartridge bearings lasted a lot longer in my experience. The Octalink one in my MTB was over 10 years old and never been touched when the thing was stolen. They were tucked right inside the BB shell which I think protected them from the worst of the spray from the wheels. My son however managed to trash his cheap one pretty quickly

crankycrank

^^By "bb shell" I meant the part of the frame that the BB is inserted into not the plastic sleeve although also putting a drainage hole in the plastic sleeve may be a good idea in your case .

ben-----

crankycrank wrote:

^^By "bb shell" I meant the part of the frame that the BB is inserted into not the plastic sleeve although also putting a drainage hole in the plastic sleeve may be a good idea in your case .

Oh I see. I thought the BB shell was that plastic thing. No, don't think I'll be drilling a hole in the frame, sounds a bit too drastic to me! I'm sure it makes sense though. OK, thanks.

ben-----

crankycrank wrote:

^^By "bb shell" I meant the part of the frame that the BB is inserted into not the plastic sleeve although also putting a drainage hole in the plastic sleeve may be a good idea in your case .

Turns out my frame has already got a hole there, two actually. One larger one where the screw which holds the gear router plastic thing in place, and one smaller one which must be to let water out. Unfortunately the plastic gear thing cover over that hole.