I had the GRiSO swingarm pin and the bearings out and the suspension con rod linkages apart for greasing. When putting them back again last night I was thinking about protection, particularly in relation to swingarm bearings and after seeing photographs of those bearings completely destroyed by corrosion. Previously I had thought I would add a rubber flap to protect the shock – which is what I did on the V11 a lot of years ago and it did the job fine – or maybe put a rubber tube around the shock.
But now having seen the exposed swingarm pin and how vulnerable the bearings might be to water ingress, I think that protection of those bearings is really the main concern here (rather than the shock) and particularly when the bike is used in areas that have a lot of rain.
I've seen people asking how the tapered bearings get so dry of grease and so badly corroded... could it be too enthusiastic power washing, for example? It seems to me that it's likely to just be rain water and dirt flung onto the pin by the back tyre that's getting into the bearings. Correct me if I'm missing something, but I think that the swingarm pin / chassis is not adequately sealed. There is a gap between the pin and the chassis holes where the pin enters, on both sides. When the pin is being drenched, water will enter through those gaps.
Does anyone else have thoughts/observations on this as an area of water ingress? There are seals on the pin between the bearing taper ends and the inside of the chassis holes but they are by no means a tight fit between bearing and chassis to provide a watertight seal. They freely move along the pin. I suppose they would act as drip rings, preventing water creeping straight on to the bearing. Why isn't a seal used in the chassis itself where the pin enters, to keep out water? Or a tube to encode the swingarm pin?