Corrosion on Shaft Drive Arm

[ArfurD]

Hi,

I have this bit of corrosion type thing going on, on the shaft drive. 

Is there something I can do to stop it?
and
Should I be worried about it?

TIA

[Noggin]

Looks like Ali rot, I would scrap as much flaking paint off wire brush the Ali rot clean  with some paint thinners etc then spary with some black smooth hammerite or simular, I'm sure someone else far more experienced then I will be along soon to give a more in depth view 😉

[digital]

As Noggin has said, if I should do that, but first, I would take the entire tapered case and rear brake caliper system apart, check the inside of both, apply grease to the points where they require grease, as well as the bolt. . which is attached to the swingarm rod and any area you think needs to be lubricated.

Disassemble the brake caliper, clean its interior, pistons, plates that hold the brake pads, etc. All that I think is not in good condition and corrosion has been able or has reached its interior. (it's like a bad apple).

It is also convenient before carrying out the work to check the condition of the conical box (cardan), placing the motorcycle on the central stand and with both hands grasp the tire and check from left to right and from bottom to top to see if there is movement . There are open threads about it.

[Novocastrian]

After 67,000 miles on all weathers (posted also in our Trophy 1215 FB group), think this is just paint breaking up from the aluminium, just as we used to get on the previous 1200cc model of Trophy with the Black engines.  Blast, or wire brush and repaint I would suggest.

[Coconut]

"Filiform Corrosion" ( Google it ! ) is fairly common,
fortunately it is usually only cosmetic and not structural.

Yours seems to be quiet a severe case and has probably been spreading
for several months or longer.

If the part can be removed from the bike it will give a better chance
of cleaning as much of the corrosion away as possible,
by wire brushing / sanding to get back to bare metal,
and using a suitable cleaning product such as Alubright Deoxidiser.
( Use with caution following manufacturers instructions ).

The surface should then be treated with a specialist Zinc-rich / Self etching Primer,
specified for use on Aluminium, before over-painting with a durable paint finish.

As digital mentions, you also need to check the rear Brake Caliper
and rear brake components for further corrosion, including the Hydraulic Brake pipe
which looks like it could do with a clean, and replace that if it is pitted or corroded.

I'd also consider, if parts on the back end are corroded like that,
what's the rest of the bike like ?

Check the Front Wheel Bearings, Front Brake Calipers, Front Fork Tubes,
Rear Suspension Unit Lower Linkage Bearings and Sleeves -
all of which may have been neglected and be in need of some TLC !

Cheers 

[sin_tiger]

He's not alone Coconut, mine looks pretty similar to that. It started showing signs of lifting about 1 month after the warranty ran out and other things started to pop up    Mine has not been neglected, washed after almost every ride, religiously during  and regularly treated with ACF 50, FS365 and XCP Rust Block, nothing seemed to make any difference to the corrosion progression. This isn't the place to go into further detail, so I'll stop there.

In the past I've buffed the flaky areas and spot painted but it's never lasted very long. I intend to strip the final drive, blast it and powder coat it properly, it'll probably need hot shot and possibly more than one coat to get a decent finish back.

For anyone contemplating this, do NOT use a steel wire brush, it will leave small particles of steel embedded in the alloy that will only accelerate further corrosion, use either a brass wire brush (not so effective being soft), a stainless steel wire brush or non metallic non woven abrasive pads (pan scrubber type material) or wheels. You can get small ones in various grades for small rotary tools, a flexible drive is useful.

[HACKLE]

Probably all to do with the "salt/de-icing" stuff that's put on your roads over their in the UK. After 90k kilometres my bikes swinging arm drive area is like brand new. 

[digital]

I believe that it is also due to salt and thaw, it does not happen to me, it is always clean and when it rains some mud falls on it, but just by wiping it with a dry or slightly damp cloth it remains as good as new.