Swing arm bearings

[Duane.Hoffeldt]

Has anyone tried to replace the swing arm (shock link) needle roller bearings with bronze bushings instead? If not, can anyone think of why this would be a bad idea!

[Alf]

Hola
the swing arm axle is made from steel, so I thing the axle would trim material from the bush when rotating

I´m going to change the swing arm bearings this week like a matter of course, because the bike has been running with them around 200.00 kms, and those are the only bearings that I have not changed from my bike, but there is no play at the swing arm, and no marks on the axle, so the OE bearings look very hard and very good bet

Regards
Alf

[TheRadBaron]

I'm not a suspension expert by any means, but I think that the stock roller bearings are very superior to bronze bushings.  I think that they offer more precise clearances and better wear characteristics, at the very least.  Is there a reason that you're thinking about swapping them?

[Duane.Hoffeldt]

Thanks for the replies lads.
Whilst fitting shorter dogbones on the weekend I discovered that the bearings that hold the dog bone to the swing arm were rotating very rough. I pushed the collar out of the bearings to discover that the collar had been damaged. The collar had slight indentations correlating to the contact points with the needle rollers around half of its circumference on either end. Clearly the collar and bearings need replacement but this got me thinking about how this damage occurred. I came to the conclusion that either (or both) dirt ingress or water ingress causing some rust eventually resulted in the damage. Now the original bearings are supposed to have a seal to prevent this from happening but the way that I see it, if this seal starts to fail, its actually easier for dirt or water to get into the roller bearing and get trapped because there are gaps between the rollers which holds the grease and this traps the dirt and gumpf that ends up causing all the damage.
And thus the birth of my idea to replace the bearings with bushes instead - I am thinking of using self lubricating bushes with appropriate hardened steel collars and then to top this arrangement off with a double lipped oil seal on either end to keep the crap out. I am not concerned about the connecting bolt shaving the bushes because it will never come into contact with them - it will be suspended in the bushes by the hardened steel collars as per the current design. I think with this arrangement there will be less opportunity for dirt or water ingress and because the range and frequency of motion in the bearings while in use is so small I reckon  bushings would easily cope with the rotational forces. However what I am not too sure about is whether a bush can cope with the kinds of compressive and tension forces that they would be exposed to.
Thus my question about whether or not anybody else had tried this modification and if so, what their experience was.