St1100 swing arm. The Achilles heel!

[CYYJ]

...The rotting of the swingarm really isn’t a thing here in the US (mostly in the UK) ... I assume more salt spray in the air, etc. in the UK...

The UK has what is called a "saline atmosphere" - it's surrounded by salt water, winter temperatures are mild, and humidity is high. That, plus a longer riding season in parts of the UK (leading to riding the bike when roads have been salted) is why rotting swingarms are common in the UK.

The problem is not limited to ST 1100 swingarms. I have seen the same problem with aircraft operated in UK coastal areas, and automobiles in the UK.

In other words, it's a regional thing caused by the nature of the climate.

Michael

 

[rwthomas1]

The UK has what is called a "saline atmosphere" - it's surrounded by salt water, winter temperatures are mild, and humidity is high. That, plus a longer riding season in parts of the UK (leading to riding the bike when roads have been salted) is why rotting swingarms are common in the UK.

The problem is not limited to ST 1100 swingarms. I have seen the same problem with aircraft operated in UK coastal areas, and automobiles in the UK.

In other words, it's a regional thing caused by the nature of the climate.

Michael

Happens here in NEW England as well, its just that its too damned cold to ride in winter, so the swingarms don't rust out. But road salt? Yeah, we got that. And now "brine" which is even worse....

 

[CYYJ]

...road salt? Yeah, we got that. And now "brine" which is even worse....

Up until about the 1980s, we were all more aware of rust affecting automobiles. Then the auto manufacturers substantially improved their rustproofing practices, and we don't need to worry about rusting cars anymore.

But - motorcycle manufacturers have never rustproofed their products. Once the first application of salt or brine has been made in the late fall, my motorcycle is off the road until there have been several hard rains in the spring to wash all the salt dust off the roads - typically the end of April where I live. I think it is wise to avoid the temptation to take the bike out for a ride on one of those exceptionally nice and sunny days in March, this because although the roads may be dry, there is still a lot of salt dust on them, this dust will settle on all the metal parts and corrosion will begin once humidity rises a week or so later.

Michael

 

[rwthomas1]

Up until about the 1980s, we were all more aware of rust affecting automobiles. Then the auto manufacturers substantially improved their rustproofing practices, and we don't need to worry about rusting cars anymore.

But - motorcycle manufacturers have never rustproofed their products. Once the first application of salt or brine has been made in the late fall, my motorcycle is off the road until there have been several hard rains in the spring to wash all the salt dust off the roads - typically the end of April where I live. I think it is wise to avoid the temptation to take the bike out for a ride on one of those exceptionally nice and sunny days in March, this because although the roads may be dry, there is still a lot of salt dust on them, this dust will settle on all the metal parts and corrosion will begin once humidity rises a week or so later.

Michael

I dunno. Where I'm at there are rust blisters, bubbles at the bottom of doors, rockers, etc. after 5-6 years. 10 years pickup wheel arches, cab corners, rockers, etc. are gone. Cars show blisters at the dog leg in the rear and right behind the front wheels. People don't seem to care, they trade in every 5-6 years. I've been able to keep my stuff nice but it has taken a "Jim Jones" level of fanaticism to keep it at bay.

 

[ST1100Y]

But - motorcycle manufacturers have never rustproofed their products.

Dunno... the ST1100 frame and swing-arm appear to be galvanized, primed, the outside then finished with black coating... and quite corrosion resistant, takes a while till it blossoms on spots the coating is damaged...
The wrapping around the cross-member has drain holes, but the cavity will clog with road grime over the years... like the pockets in the wheel arches on cars will accumulated dust/sand hold humidity and the winter salt brine...
If not removed/diluted by frequent washing, those nests sit there, creating havoc...