I suspect many people have thought about this before, but I want to know why frames do not use roller bearings in the linkage bearings instead of ball. As the frame ideal only moves in a single plane and you want to avoid any lateral twist a roller you would think a roller bearing would be much better solution ?

I wonder why they don't all use a bush with a grease port. Frame bearings are hinges and I am under the impression that using rollers for that sort of application leads to brinelling and makes for a heavier part.

(I know some frames use bushes)

Oh no – you've asked a question about bearings!

Bushes have too much friction don't they? Incidentally i've just fitted enduro shock eyelet roller bearings in place of the bushings, much better small bump performance. Apparently last longer too

weight

Just popped the main swinging arm bearings out of my Devinci, and they are roller bearings, got a grease port too, shame the pin they roll on is made of cheese, as its that that seems to have the wear on it, bearings look fine if a bit grubby.

Micro needle rollers are lighter than balls, but tend not to have any axial motion restriction (same as most full-size ones) – even though you THINK your frame only moves in one plane that simply isnt the case, any amount of frame flex/twist/off-centre loading will tend to make an axially-free bearing tend to move axially. You could use end-plates to prevent motion, but then you're increasing the friction again so you've defeated the purpose.

Add to that the fact that the shaft they run on needs to either be sleeved or ground and hardened and you're looking at the same or higher manufacturing costs.

A few do, but the mags usualy slate them for being sticky.

Bushes on my Turner – great.

Needle bearings have issuee, because once they get contaminated with grit, the needle can't "plow" the grit out of the way like a ball can, so they tend to jam up or wear out much quicker.

Why not just ask Kaesae 😆

thisisnotaspoon – Member
A few do, but the mags usualy slate them for being sticky.

I wonder how/if they measure the extent of that? Visions of a high tech test bench. 🙂

Just the static force required to initiate movement of the suspension I presume? Load cell and a hydraulic piston would do the trick.

Probably a mix of prejudice, towpath riding and bad journalism.

as soon as you go round a corner the swingarm bearings are subjected to axial loads.

The only problem with bushes is they are cheap.