Swingarm bearings!

Pulled the linkage bearings and bushes and while at it the swing arm ... despite there being no play it, it was not a pretty sight I am surprised that there are no seals and no zerks to make lubing easier? Some Italian engineer dropped his pencil for an early lunch. Anyone fitted zerks here? I also think if one pressed the end bearings in a little further you could get a seal in and still have a grease reservoir between them in line with a zerk. I really think this is a weakness.

I think fitting zerk's to the swingarm would be a fair challenge without interfering with the bearing itself, unless there is some sort of standard size 'end cap' you can get that sits on the end of the bearing and lets you pump in grease from that direction with a zerk fitted concentric to the bearings axis in the swingarm.

I agree though, i was surprised to find zerks on the linkage bearings but not on the swingarm ones, I had assumed they'd be sealed ball bearings when i first looked at the bike, lo and behold, they aren't...

I have to drop the lot at least twice a year and do all of the bearings. A tip. do not clean off all the over run grease. It will last a ride or two thereby extending the internal cleanliness and integrity a tad longer.

Yeah had another look - it would be tight to get them in the centre at the top - clearance is tight and on the LHS you have the chain and slider slider ... I must come up with a plan to ease this situation. At the moment it is so easy for water to get to to bearings it is ridiculous!

You could seal the swingarm shaft and put a zerk in one end.
Drill some holes radially in the swingarm pin to feed the bearing sleves.

Let em know how it works out.

Nice idea - will look at the possibilities. This is in fact similar to the setup on my BMW G450X.

I think it may be easier to just fit a zerk (what we call a grease nipple!) on the RHS and close the other threaded nut end and pump the whole shaft full = but will see. Some careful measuring for the grease ports will be needed so that they align with the reservoir between the two roller bearing on each arm. But should be doable and certainly easier than pulling the swing arm every time to lube!

Some question I have:
How many holes are you going to drill for each bearing (or each set of bearings)?
What diameter holes?
(and/or how far between the hole edges or centre to centre?)
What holes pattern? (Radially and at a distance along the pivot bolt so as to align with the gap between the bearings on each side of the swingarm is what I got from your last post).

This does seem like a good idea, my only concern is taking out to much material from the pivot bolt and eventually (or sooner than eventually) finding that it is cracking between the holes....I don't suppose that particular area is subject to huge bending moments since it is so well supported on each side and most of the load would be taken up in the swingarm casting, but still, it would be a bugger to go to all that trouble just to have bolt crack.

Personally I have no idea how you could determine the likelihood of fatiguing the pivot bolt without some sort of modeling software, just wondering if you have done something like that, or if you're just going to give it a shot.

The holes should be small (you don't exactly need to flow a massive amount of grease). That shaft should not be in bending if it is properly torqued. The likelihood of failure is really low. Should be fine.

The only trick is measuring the location of the centers of the bearings to put the holes, but that's not too terrible with a little creativity.

i did all that drilling on a 84 RM250 worked fine a the bike is still going strong but next time i think ill make bushing from HDMP or 954 navy bronze

I have not decided on the diameter of the holes but will probably take my cue from the linkages. One hole each side should suffice and the measurement will be easy as everything is out - vernier will sort that. Yes between the two bearings on each side. The shaft is pretty strong and really just holds and tensions the gudgeon spindles that in turn take the force from the needle bearings. I am indeed just going to give it a shot.

Subscribed for this mod



.

Sounds good. Since I have the pivot bolt and everything apart and cleaned at the moment, I might try and have a look at this over the weekend and see what I can come up with. Really though, it's going to be much the same, I was thinking of 4 small holes, drilled radially into pivot bolt in line with the gap.

The shaft is hollow but has quite a thick wall - may still look at zerks on both ends, just easier not to have one on the nut end but with a socket wrench may be enough depth. Not sure what overgreased would be ... ideally I would like to be able to grease these buggers until I can see the grease exiting the gaps at the frame/swingarm = this is where there is water ingress due to a lack of seals. The other option of course is to look at a single wider bearing and seals both sides like many other bikes. Ideally then a machined recessed lip would help the seal seat (much like on the linkage).

Personally I would not do four radial holes - this is more likely to weaken the shaft at that point. One reasonable size should do the job IMO. You just want to get the grease through it will rotate and circulate through the bearing action and pumping pressure.

Here is some info
swingarm bolt on page 2

http://www.thumpertalk.com/topic/572940-installing-grease-fitting-on-lower-shock-pivot-wpics/page-2

Thanks Will.

EDIT: Really wish I owned a drill press for jobs like this

Great link, thanks - clearly great minds think alike While this is on the TE250 it is pretty similar. OK two grease nipples looks like the way to go and yes one would need to drill the gudgeon spindle as well and align.