The ‘frame’ on my Trek Fuel EX8 (2009) has bean creaking; closer examination shows that at least two of the link bearings have seized (no…..I don’t pressure wash it!).
Being a tightwad, is it false economy to buy cheap ebay bearings, accepting that they may need to be changed more regularly? Can they be any worse than those that Trek have fitted?
I understand that Trek will replace free of charge, but only if fitted by a dealer?

You’ve answered your own question surely, if Trek will replace FOC buying anything is stupid

It depends a lot on the fitting. If the bearing’s easy to knock in and out (like a front wheel bearing in most hubs) then cheap is fine. if it’s a hassle to do, then the extra labour is worth avoiding.

SKF were about 5x the cost of the cheap ones I bought. Would they last 5x as long…I’m not lashing out the cash to find out. After trying out the idea, I have found out I canget 3x the life from the cheapos by opening the seals & packing more grease in.

what are the serial numbers for the bearings? i just ordered some SKF bearings from ebay for my top fuel, price was a bit more but not alot in it

Steve, as I understand it bearings are free, fitting isn’t. Personally, I’d rather look after my bike myself.
I used ebay bearings in the hubs, they’ve lasted longer than the originals!

Get bearings from an online bearing factor like akbearings, CAREFULLY prise the rubber seals out, get some more grease in there (both sides) and it should increase their lifespan.

SKF etc are worth 5 times the cost of cheap Chinese bearings, (you can pay less), in the case of frame pivots do you really want to be potentially damaging the seat everytime you mess with them. For frame longevity I’d just use decent bearing

I think Trek sell the complete rocker link with the bearings complete. This is because the bearings are allegedly impossible to change

get some more grease in there (both sides) and it should increase their lifespan.

No… read the bit about over packing bearings…..
http://www.boucherandjones.com/grease.htm

All that happens when you overpack a bearing is that the grease gets pushed out to the sides and the ball and race run in the grease that is needed, the stuff pushed out to the side then creates resistance and drag making it harder to move/rotate. The excess grease will also start to degrade.
I work on equipment that runs 24/7/365 and we do not repack any bearing. Manufacturers pack a bearing to do a job.

http://www.brammer.co.uk/uk_brammer_bearings.aspx

I think that the ‘one piece rocker link’ is only on the older models; the magnesium bit on mine has removable bearings.

My Ventana has double row bearings. Using SKF would cost me a fortune.
I’d have to sel the frame to buy the bearings.
🙂

The BIG problem with MTB bearings is that very often they start life with no grease at all!! Manufacturers should pack them but i imagine mtbs application is a rather different than the bearing manufacturer anticipated. As Kaesae has correctly said many times on this forum, the right grease makes a massive difference. I have had great results over the years simply by carefully removing bearing seals and applying fresh grease and turning the bearing round to work it in. I am also careful with washing. Some of the Rock n roll greases are v.good. I would not risk fitting cheap bearings. I believe bearing manufacturers just blow grease into the races with an air gun. On cheap bearings this will be done sparingly to save cash as grease is expensive. You get a lot of “duds” with hardly any or no grease…

Trekster – Member
Manufacturers pack a bearing to do a job.

Which is generally a reasonably high rotational speed function where being packed full of grease would cause overheating and premature failure.

On the other hand mountain bike use is either low speed full rotation or very limited rotation, neither will create heat from over packing. But it will help to stop the ingress of contaminates.

Oh and don’t blindly follow the SKF path as in 20 years of testing high load/vibration applications we have found NSK to be superior as the cages are less prone to fracture.

Packing suspension pivot bearings is a good idea i think – they move a fraction of a rotation their whole life, so the main thing you want the grease to do is keep the water out. The slight additional friction this grease causes is completely meaningless in a rear suspension system and pales into insignificance against shock bushing friction and shock stiction.

Pack them.They arent rotating so take no heed of the blurb above.

If the above poster thought out of the box and into reality.. they would see that many mountain bikers could easily spray the hose against the shields when washing the bike down.So filled with grease is the way to go in non rotating pivot bearings in frames.

As far as deteriorating grease behind the shields is concerned,its a nicer thought knowing theres grease in there and not some void to hold water,dirt and rust.

All my experiences with non-packed and packed bearings show the packed bearings have a substantially longer life.

As has been said, mtb bearings suffer (relative) low rotation and work in very harsh (dirty and wet) conditions. Nearly all my bearings ultimately fail due to dirt and moisture ingress followed by rusting out and going lumpy and loose.A void filled with grease can’t be full of muddy water.

Where’s TJ to argue against packing bearings?

As above, the bearing, are designed, spec’d and made for indoor high speed use-the complete opposite to mtbs.

PACK, PACK, PACK…

These bearings are failing due to internal rusting, packing them with grease is the only logical course of action.

Only problem is that the trek ex fuels run a custom bearing in the main pivot 6903 e type, extended inner race, only two companies manufacture them.

Trek have a contract with JNK which are shite in my opinion, the other supplier is enduro, the enduro and JNK bearings are similar in terms of quality, however the enduro bearings are factory pregreased 100%.

So for everyone saying that you shouldn’t pregrease bearings 100%, why do enduro do it and have reasonably good results from doing it ❓

Best course of action is simple, buy top end bearings SKF, INA/FAG,NSK what ever you can get at good prices and then every 12 to 18 months open up the seals and stuff them full of fresh grease, rotating the bearing to work it in.

Good luck servicing your frame 😀

Aren’t many of the bearing failures reported on here actually due to lack of use?

BWD, you have a point there I think. BB bearings especially seem prone to seizing when not used IME.

I’ve just put some (cheap) bearings in a hub. I used similar last time but they didn’t last that long so this time I filled them full of grease…. I have to say there was precious little grease in them as supplied.

The grease I used was the stuff we fill pivot bushings with on the loading shovel at the quarry. It’s good shizzle! –
Total Multis Complex EP2 (UK)
I use it in loose hub bearings too, and I seem to get very good life out of those. Time will tell! 🙂

Lack of use will simply excellerate the effect of the rust causing to to build up far more quickly.

Same principle as moss growing on an unused cars tyre or grass growing on an unused path.

Leave the bike sitting about unused and you simply excellerate the internal rusting. This leads to it building up and seizing the bearings.

Other contaminants like silt left behind by water and hardening grease over time will also cause bearing to sieze.

I recently serviced a Mondraker Summum sponsorship frame, it was running SKF bearings that were only 6 months old, the bearings were ruined due to the bike being used a lot and also being jet washed regularly.

Had the SKF bearing been full of grease they would have lasted a lot longer.

Would it be possible to run a bike without bearings? They do seem to be a major weak point, it might make more sense to look for an alternative solution. For example, the world spins rapidly on its axis, but to the best of my knowledge has no bearings fitted, whatever the technology in use there might transfer really well to bikes.

Acellent 😀

BWD IIRC this is what Turner do isn’t it? They run bushing instead?

“Would it be possible to run a bike without bearings?”

There are air bearings – typically used for incredibly high rotational speeds no grease.. the earth kind of spins on bigish air bearing.

Bushings are really the correct solution for the type of bearings in suspension systems for bicycles , it just takes rather more work to execute effectively than bunging in a very cheap roller bearing.

If they were all sealed properly then we would not see problems.

Definitely pack em full of water resistant grease

Everything used to be bushings, but a worn bushing can trash a frame in a way bearings can’t. Used to get tonnes of stiction too.

Anyone ever tried full ceramic pivot bearings? Be rather expensive, but they should basically last forever, just flush with water if they get full of crap!

to get back to the original question, yes cheap bearings are a false economy. I bought a pack of 10 * 6001RS2 bearing off ebay for about £8, to use in my hope wheels. SKF bearings are £4 or £5 each.

The cheap bearings last abot 6 weeks then disintegrated. The ball bearings just collapsed, leaving the inner race stuck on the axle and the outer race stuck in the bottom of the freehub. Spent more replacing them than I saved on the bearings 😐

Hahaha! I mentioned about 18 months ago that the maintenance time off sets any benefits from using cheapo bearings, I don’t have a problem with my frame bearings or hub/bb bearings, they last years.

You need to buy top end bearings and simply recondition them every 12 to 18 months.

I will try and set aside some time to do a guide on removing seals and refilling bearings with grease (reconditioning).

That said I am very busy, good luck to everyone choosing bearings and servicing your rides, if anyone knows how much of a shitemare it is, I certainly do 💡