Any reason not to get black oxide bearings for my frame?

They were actually cheaper on Simply Bearings, but apparently are better.

Oh and congratulations Trek, you win the award for most under-specced bearing application for the main pivot on the 2013 Superfly FS.

7 years is a good innings for any mtb bearing

Can you get the fancy new bearings with the solid lubricant? Those might last longer.

They cant be worse.

7 years is a good innings for any mtb bearing

No idea how many times they were changed before but I’ve had the bike since 2015 and changed them once, so it’s looking like 2 years each which isn’t bad. But anyone know about black oxide specifically? That was one of the choices and was cheaper than non-black oxide.

What will last longer next time is very dependent on the failure mode this time.

Bookmarked.
I just use enduro max for pivots. They last a year usually, but the cause of failure is water/grit getting past the seals. Not sure if a fancy coating on the races will help, unless these BO bearings come with better seals?

Enduro LLU max come in two flavours – black oxide and not black oxide. The former are slightly cheaper. According to the internet the oxide layer can help prevent rust by keeping lube on the balls better if it’s the right lube.

I have a theory that seals are generally ok in normal use, but when the balls are overly compressed or they wear slightly then the seals are no longer in contact and that’s when water gets in. Which is why they seem to fail suddenly. Just a theory though I’m not a mechanical engineer.

Interesting. Just popped off the seals and there was no grease inside. Not much rust in evidence. So where’d the grease go?

Washed out when you washed the bike, or worked out when riding.

Seals on little bearings are generally rubbish. If I get 12 months from EnduroMax bearings I’ll eat my hat.

Not sure why they don’t offer seals with snap rings on them. The extra seal friction shouldn’t be an issue.

I’m absolutely not an expert on bearings, far from it but my internet based research tends to say choose same hardness material for race and balls. Otherwise the harder material just wears away the softer material.

If the oxide layer is same hardness and just adds to the corrosion resistance then I can’t see any harm?

+1 for enduro bearings being massively overrated. We’d never dream of using them in my industry (marine ship systems). I’d always specify SKF or FAG. I also like hope bearings from a mountain biking viewpoint. Anyone know who the OEM for them is?

For any mountain bike bearing, the main cause of failure is corrosion from water/mud ingress. Apart from a very well sealed hub bearing, I’ve never seen a bearing failure arising from standard wear to the balls/races. Every frame bearing I’ve ever pulled has had more mud than grease inside by the time it’s failed.

With the cavet I’ve never used them, I can’t see much benefit from the Black Oxide bearings. The balls aren’t coated for starters, and they subsequently can corrode and bind to the cage and race. I’d also have questions over the wear resistance of the black oxide coatings on the races. Frame bearings are constantly subjected to non-linear radial and axial loads which really isn’t good for bearing longevity and I can’t see the coating lasting in these conditions.

The best way to keep any mountain bike bearing going is to repack them from new with a decent marine grease. Most bearings have around a 30% grease fill, because more than that increases friction significantly, which matters when on a rotating piece of machinery at 1000rpm, but not a frame bearing that never completes a full rotation. Even enduromax bearings which have been designed for frame bearings aren’t sufficiently filled imo.

The full compliment bearings are a great idea in theory as most frame bearings are undersized for the load conditions. But again corrosion is the usual failure mechanism, and they need a small grove in the side of the race to fit the balls into the bearing during manufacture. This provides a weak point in the sealing interface and further enables water ingress.

The best way to keep any mountain bike bearing going is to repack them from new with a decent marine grease.

I’ve read this before, and agree with the theory, BUT how do you remove the seals without damaging them, therefore degrading the seal and negating the benefit of a good grease pack?

+1 enigmas on all counts.

Enduro bearings aren’t poor quality by any stretch, but they’re not really particularly special either.

I also like hope bearings from a mountain biking viewpoint. Anyone know who the OEM for them is?

I used to know a guy who worked at a bearing manufacturer near to Birmingham, Hope was one of their customers. Anyone know of any bearing manufacturers near Birmingham?

Hope have used a few suppliers, the last ones I got from them were INA (which are excellent)

+1 about Enduro, they’re just not that good.

BUT how do you remove the seals without damaging them

Very sharp scalpel type knife blade ran around edge, pack grease and install putting the side which had seal removed on the inside facing away from worst of the filth.

BUT how do you remove the seals without damaging them

This is pretty easy. A stanley blade with a point, or a pick on the outside diameter edge, because this doesn’t see any rotation.

Very sharp scalpel type knife blade ran around edge

A stanley blade with a point, or a pick on the outside diameter edge, because this doesn’t see any rotation.

Riiight….. I can’t see my shovel hands managing that without slicing the lip off, whether it’s rotating or not, it’s still a seal. And particularly no good for bottom bracket bearings, they attract filth from both sides.

Most bearings have around a 30% grease fill, because more than that increases friction significantly, which matters when on a rotating piece of machinery at 1000rpm, but not a frame bearing that never completes a full rotation.

The most sense typed here. Even wheel bearings don’t rotate fast enough to cause an issue.

Get yer bearings packed.

Metal dentist-style pick is pretty safe. Thing is, it doesn’t have to be absolutely perfect, you just need to lose less from removing and refitting the seal, than you gain by adding grease. I’ve no idea if I damage or reduce the effectiveness of seals when I do this but I’m 100% confident that I incresae the lifespan.

Riiight….. I can’t see my shovel hands managing that without slicing the lip off, whether it’s rotating or not

If you like mechanical sympathy then no one here can help you.

I’ve had success with a normal pin or needle when removing seals. They are pretty fine.

I will try a different brand next time but I’ll say that Enduro Max claim to be filled with marine grease. Not that it helped these ones mind. It’s difficult to imagine (although not saying it hasn’t happened) how enough water could have got in and out of the bearing with its seals intact to actually wash a decent amount of grease out. And there was no rust inside which suggests not much water got in either. Suggests that it’s being forced out somehow, or it’s degraded. It was sort of black and grimy inside.

EDIT finding SKF with max fill seems to be tricky though, as they don’t call it that.

NTN or another japanese bearing manufacturer – nsk, fag e.t.c.

Bling bearings are for the kind of people that buy oversized jockey wheels and yetis.

i am trialling the black oxide ones at the moment. never used them before so cant comment.

when i do swap bearings i keep the dust seals off the old ones as spares incase i knacker some. Ive not found a source of new ones yet.

I fill mine with marine grease. a stanley blade is imo too big to remove them without damage. A pin or needle works much better. Ive got a selection of seal picks but by far the best is a sharp dentists tool. there about a quid off ebay.

lift the outside edge of the seal and once you can get the toolunder the metal ring in the seal it just pops off. If your packing them put a blob of grease in the palm of your hand and work/press it into the bearing till it comes out the other side.

Wouldn’t it be nice if all bearings on a bike had a simple method of adding grease and driving out the gunk from the bearings?
Simple 1800s technology, an oil port or a grease nipple. is probably why so many 100 year old bikes are still rideable on their original hubs and BBs.