st1100 Swingarm refurbishment

gar

Looking for some advice. I have a 1991 st1100 60k miles, and as expected is starting to show some basic surface rust on the swingarm. I can see that there is an ever present drop of water on the underside of the swingarm in the place that most of them rust through (if you turn it upside down, the bottom right of the 'u' shape of the swingarm). I have poked around this bit and there doesn't appear to be a hole so I'm guessing there are very small ones appearing through the metal??? I know water gathers there if it has been ridden in the wet but there is still a drop there days after the bike has dried in the garage so I'm thinking it has got into the inner section of the tubular steel.

Anyway I'm thinking of refurbishing the swingarm this winter to try and avoid the ?250 cost of a second hand one and proactively guard against any major corrosion. I'm thinking of sand blasting it, filling in all the gathering points and small nooks which Honda have left in its design, then galvanising it and painting it over. Is this job as a whole recommended and if yes is the galvanising a good idea or would a lick of zinc paint do the trick?

What else would you think is worth doing while the arm is off - I've seen guys mock up mudguard extensions to try and protect the swingarm better, and also do the swingarm bearings.

Any thoughts from the experienced owners really welcomed.
 
It's possible that the drops of water are from the muck that accumulates, or from the breather hole (which is there for when they weld it together). But you seem to think not. Is it coming from elsewhere and running to the lowest point perhaps ? Whatever, I always wanted to be certain that the whole unit was solid, and that I wasn't about to go papering over cracks.

I used to take mine off every couple of years and give it a good seeing to, and a thorough check over and prods to locate any corrosion. There's not much you can do on the inside, but I did spray with WD40 and made sure that it got distributed around. I also left it hanging for a few days in the warm to help to lose any water.
I reckoned that anything I put on was going to get blasted off by the kick-up from the road, so I only ever used Hammerite on it. A few thick coats would see it through the next 2 years.

The bearings never needed doing - the seals were good, and I'd clean and re-grease, but it wasn't really necessary. There would be dark marks on the race casing inside the arm, where the needle rollers sat, but no sign of roughness or indentation.

The only other things I did while it was off, was to give the final drive housing a good clean - especially the 4 bolts which hold it on, and I'd usually take of the suspension unit, clean that up and coat the outside with grease. (I used to ride a lot in winter !). The suspension mounting bolts and bushes would get greased and checked over / replaced.
 
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