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Damage cause unknown

Damage cause unknown

I started to polish the chrome and metal on my bike and noticed this.  It like I road through an acid storm.  This is after I polished them, they are apparently permenent.  No other part of my bike has this except the lower forks.  I was wondering if:

1. Anyone has this and can tell what caused it.
2. Any ideas how to fix it.
3. They used to make lower folk chrome covers but I can't find any anywhere.  Does anyone know where to get them.


Own Photo: 



Wow ! The only time I've seen fork lowers in that condition was on a friend's bike that was stored outside, without a cover , in a seaside suburb of Sydney. High humidity and high salt content in the atmosphere pitted the polished alloy over the years. The pitting was too deep to polish out. My friend eventually had the fork lowers powdercoated in high gloss black ; chroming was too expensive for him and no fork covers were available for his model.

stored in garage. no salts used here.

Good luck with it!

to me that seems to be that fine salt that hangs in the air on the coast. Do you do any riding along the west coast area and don't wash the bike right away? I had a slight amount of that appearing when I rode over there last summer. Noticed it when I went to wash the bike a week or so later. Any one who lives on the coast area fights with the salt in the air corroding things. One reason I won't buy a car from someone who lived on the coast.
-- had all my metal buckles on my pair of roller blades looked like that when I went rollerblading just for one day along the coast when on vacation. I didn't even get them wet, it was just the moisture of humidity with salt mixed in it.

What ever is pitting,rusting your chrome is working on your shocks. Wash them down with baking soda this will stop the etching from the acid from what ever is eating away at your lowers. Get some good metal polish and start rubbing. If that does not help you may have to get some wet dry sand paper 1000 or 1500 and start wet sanding until it's shinny again. I have done this but it is a ton of work.

It is definitely corrosion of some sort. The fork legs are polished alloy and have a clear coat of lacquer over them.
Once the moisture has penetrated either from the outside or from aged porous metal from the inside, that is what happens.
I have a mate with the same condition on his bike. He spent a lot of time removing the clear coat and polishing with emery and 0000 steel wool. They look great now.
I had some early signs of it on my VT1100 and sanded them back and painted them Black.
Good luck!

What about dismantling the front end and taking the lowers to a professional metal polisher? It can be a six stage process to restore the metal but it sure does save a lot of elbow grease and sweat!

Its the only place on my bike where it is happening...both forks same pattern. The picture is after metal polish. The sand paper sounds good because the rest of the fork is brushed finish horizontally. Or I look for cheap lower fork replacements. Man thats a lot of work.

That's what happens with my bike when I would use it during the period of the year they use salt on the roads. And that's the reason I bought my second bike to use during winter so I can make a ride without damaging my most favorite bike, Big Red. The only way I know to get it removed is to change the parts from your bike and buy new ones or to cover it. There is no possibilty I know, to polish it away... Maybe you can find new- or used ones on e-Bay?

It's usually the protective coating. It breaks down after a few years from road grit and using fine steel wool or fine wet/dry sandpaper until they are shiny again works. Or replace the covers.

If you do manage to sand them back to an acceptable state, it is often difficult to get clear coat to stick on bare metal in a DIY context. An alternative I use on untreated bare metal (which I have on my Café Racer) is regular waxing which does a good job of keeping out the elements - except for hard crap thrown up at the bike while riding.

Yep I agree Bill. I have the same issue but not quite as obvious, the applied coating that helps protect the aluminium and stop oxidation needs to be cut right back or stripped and a new protective coating applied.

This works. You can use the Scotchbrite pads by hand but it takes a long time. Rather than the dremel/wirebrush you can use a Scotchbrite pad by hand, it just takes longer.
Or, you can see if you can find a local shop like this.

I still think there's a lower fork chrome cover, I've seen em 6 years ago but cant find them now. Looks like a lot of work to salvage the old ones.

sand back, polish and seal with incralac. my mate did his and looked better than new

Incralac ... never heard of this ... must following up if it works better than regular rattle-can clear coat. Thanks Spratty!

by wattyl. did you see the pics I just posted of my mates forks

Just had a look at the pic ... baaad! Look fwd to the After shot. I Googled Incralac and read some product notes. Application by DIYers seems to be the challenge without the proper spray gear and proper respiration gear. Can you get it in spray cans?

yep rattle can from Bunnings

after pic is up Peter just click on show all photos

Bunnings .... bewdy!!

I think when my tires need changing I'll buy a lift and pull the tires and the forks and sand, polish and seal with rattle can Incralac. I've got 7000 miles to go, or one trip to Alaska. Great comments!

Just a lot of rubbing with some polish and you are going to get black from all the corrosion you will remove. That is what happens when polishing Aluminum.

What you have there is simple. Road debris and or bugs have chipped the clear coat. Aluminum being a fast corroding metal and very porous metal it has started. Remember Yamaha loves clear coat. What I did....remove the forks and use paint stripper on them. I use aircraft remover brand. Keep it away from the rubber!!!!!!!! When all cleaned off use mothers or Lucas polish with a lot of elbow grease, it's a lot of work. When polished I wouldn't recoat it with anything but wax or you'll be back to where you are now. Every year touch up the polishing when you do the rest of the bike. It takes work but it'll look great. Sanding or steel wool will scratch the machining marks and won't look right.

This is what used to use to polish the rotor blades on the Benson and the Barnett.

You probably don't have to take off the fork, just the wheel, brakes, fender, and any attachments. And working off a lift the forks should be lower than when they have the weight on them, and just sand, polish, Incralac coat, and re-assemble. Are you saying I shouldn't use Incralac. I've been thinking of using the stuff on rusting chrome. Polish sounds good too. But Incralac I read last up to 4-5 years. They need to make a bug guard for the front forks. Like a clear plastic. Or black leather oooh ahhhh

I don't recoat anything like that. Once corrosion starts on a porous surface it's there. You can polish it to a beautiful chrome once a year in about 15 min or go through a headache process all over again. I absolutely would not sand it though, it'll mess up the machined finish. Strip and polish.

Did you see the before and after photos I posted of my mates forks that he did indeed sand, they came up better than new and won't need doing again for 4 years or more, just saying

Does this happen to your rims as well as far as clear coat?

Yes ... have seen it on older bikes

all clear coats eventually break down and bare alloy is match with the elements

I like the idea of paint remover followed by polishing, not sanding. If I could just polish away the corrosion then coat it with Incralac, which I don't know much about, except that it lasts longer than clear coat; and doing my rims at the same time. Then I would place a black leather folk cover on the forward side of the forks to protect the protective coating. Obviously, if the polishing doesn't take off the corrosion, I would have to resort to sanding.

Absolutely drew there is a point where sanding is the only option, I don't think you're that bad yet though. As for your mate spratty you're right those forks we're way beyond polish only and needed a lot of work but came out nice in the end.

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