aluminum frames and salt?
 

I want to try riding a bit this winter and snow is just around the corner.

I have my trusty rigid GT Outpost Trail (my first real mtb bike) that i was thinking of riding. It has been sitting in the garage for years. THE last thing i did to it was i put on new 7sp shifters and a full cable kit.

That said...from what i have read thus far.......scrap the gears and go SS seems to be the logical choice. Not sure if i want to do this but then again the bike isnt getting used so....


ALso....salt reacts like hell on those aluminum frames correct? WEll i imagine just as bad or worse than any other frame material.

I had a buddy ride his much newer giant Yukon wiht studed tires for about 3 rides one season and it seized up all his cables, shifters, rusted chain to hell and basicly make his bike look like a crap farm.
Knowing him..he didnt clean it after each ride..no fenders etc. Bottom line is it was toast very shortly. THat salt gets into everything.

How do you keep stuff clean? Id be up for washing after each ride or at least once a week ....however......you cant just pull out the hose. Where do you get the hot water to wash them down to keep them functioning :)

Thoughts?

I have the bike comepletely torn down to grease up the HS and wheel bearings etc. ANything i can do or should do to it while it is torn down to avoid problems in the future?

I was told by the folks at my LBS that corrosion isn't something to worry about with an aluminum frame but if you have a steel fram you have alot to worry about.

The LBS is right and wrong.

Aluminum + salt + water will corrode very very fast. Steel will corrode but more slowly.

Wash off with fresh water when you can. If it is so cold that your hose is frozen, there won't be a lot of water on the road and salty water is hence less of an issue.

Lots of oil on your chain, don't expect to keep it looking shiny, just wipe off excess gunk with a rag now and then.

Really? I have been riding an aluminum frame in a maritime environment, and through very hard winters for 10 years now, and have never seen any corrosion at all on the frame, even on the three key marks left by a moron in the dorm I stayed in college. I never rinse the frame in winter, as frozen cables really suck, and the bike comes out relatively fine in spring. Just lube the chain and derailleur a lot.

Then you are lucky. Must be decent anodizing and not the right salts.

I've seen 0.5mm pits on rims after a few weeks of a bad winter.

??? Hmmm, wonder how I made it through last winter on my aluminum bike with no and I mean no corrosion problems on the frame. Even though the metal is showing in quite a few spots. I rode pretty much daily in some really nasty stuff and only managed one washing of the bike. Now the components took a beating but the frame is fine.

Aluminum immediately oxidizes and that layer of oxidation provides a protective barrier to further oxidation. Steel just keeps oxidizing.

Some of the newer de-icing sprays that are put down will oxidize aluminum faster.

I don't wash my aluminum frame all winter... no problem.

Fenders with a large mud flap keep your ride mostly clean.
Run full housing to your gears, they'll be fine almost all of the time... run single speed if you want.
The big problem around here is the freehub grease gets water in it and freezes. Flush it with a lighter oil.

You may want to inform the US Navy of this. They've got a whole bunch of aluminum ships out there.

I used to live on a boat - I'm very familiar with salt water + metal interactions, thank you.

Medium to large aluminum vessels use active galvanic systems to protect the hulls.

I repeat - aluminium + salt + water can corrode very fast. You just need a deficiency in the supply of oxygen.

There seems to be so much mixed information. How about just not doing anything radical (like going SS) until YOU spend some time riding in the winter. Frame corrodes(never seen it myself), buy another one, maybe with disc tabs. Gear don't work well then set up SS. Cable sticks then go full housing or lube more or with different types. Just start riding and solve the problems you have as they come up. Winter is a harder on bikes, but you are not crossing some great barrier where the laws of physics are different. Most of the time you could still pull out any old MTB and get to where you need to be.

Me, I never had any corrosion on my beat to heck mid 90's aluminum bike. Had a few cable stick issues, but nothing I couldn't work through. My drive train does take a beating in the winter but it's just parts and I like the different gears over going SS. I felt I needed discs for snowy downhills. Of course this is just what I found.

The question was specific about bike frame (this is a BF after all) so in that context the LBS is correct.

That's great but those of us that have actually used aluminum bike in the winter are not seeing what you claim will happen. Heck I just bought another aluminum bike for use the winter based on how well the other one held up. And I live in northern Utah so my winter roads are crappy for months on end. My bike got totally crusted consistently and rarely washed since I had no way to do it in the freezing temps. I rode it pretty much daily and usually for at least 20 miles at a time. So lots of exposure yet no corrosion to the frame. This is my actual experience and seems to mirror the experience of many other winter riders. Just saying...:rolleyes:

Aluminum in salt water is not usually prone to complete or aggressive oxidation. As a matter of fact, it's the thin layer of aluminum "rust", or oxidized aluminum, that protects the aluminum bicycle frame from further oxidation. So in that sense, yes, of course, aluminum does "rust". However, if the aluminum frame is subjected to mud and salty sludge, then there are oxidizing compounds within the earth that have a greater oxidation potential that will compromise the oxidation-resistance of aluminum. So, if at all possible, don't worry about the salt on your bike, just worry about the dirt and sludge on your aluminum frame.

- Slim :)

I am an advocate for steel bicycle frames. However, if I lived in Hawaii, I would choose an aluminum-framed bicycle to ride on the sandy beaches and salty boardwalks. It most probably would be my Trek 7.5FX :thumb:


* oxidized aluminum = aluminum oxide

Slim is correct about the dirt.

Just don't fall into the idea that an Aluminum frame won't corrode. Unlike a steel frame, you can prevent the corrosion just by washing it clean. what I'm trying to communicate is that if you have corrosion happening to Aluminium components, it can go much much faster than it will with steel. I suggest the doubters go and learn something about electrolytic corrosion and the galvanic series before commenting further.

But even a steel frame won't instantly fall apart beneath you. My 'winter' bike is my touring bike, a very thin-walled 653 frame. It's over 20 years old. Bikes get nasty corrosion conditions here in the UK - year-round rainfall and a lot of rocksalt on the road in winter.

The LBS stated that you didn't need to worry about Aluminium, but you did need to worry about steel. They are right and wrong - both can corrode. You neglect Aluminium, let dirt and muck build up, you can get crevice corrosion in welds, and pits creating stress points. The Aluminium is then likely to fail catastrophically. Cracked steel will give way gradually.

I wish Titanium was a certain solution, but there does seem to be problems with quality control. I know a chap whose had 3 frames crack on the welds in as many years.

I've been riding a '95 Cannondale hybrid in the winter in Minnesota, putting on 17k miles in that time. I've had some problems with frame corrosion, bubbling the paint. It's been easy to take care of: scrape off the loose paint and corrosion and paint it with Rustoleum metal primer and black gloss paint to match the original, with quite good results.

The main functional problem area of corrosion has been the valve stem hole corroding enough to prevent non-destructive removal of the valve stem. Fortunately, I had my patch kit along the first time I ran into this problem and successfully got the flat fixed. I should be a little more diligent about keeping the hole cleaned up, but it's easy to forget about it and...

Hey there MNBikeCommuter!

Just out of curiosity....

Are you the original owner of this Cannondale?

How are you certain about the mileage?

I thank you in advance.

- Slim :)

I'm sure it can, if you're grounded to the earth in a tub of salt water.

I ride on my steel frames most of the time... however I do have a very well used and abused aluminium MTB which has been expeosed to a lot of winter salt... so far no problems with any corrosion.

That's a good description of normal winter riding in Yorkshire.

I've been riding my aluminum winter bike for going on 9 winters. So far no corrosion. Maybe they treat the roads with pepper instead of salt here.

Wow, I had no idea aluminum frames were so vulnurable. Glad the mountain bike I'm putting the studds on is steel.

Haha, but in all seriousness winter riding is not the same scenario as ocean vessel since you are lacking the complete "circuit" usually.

What i have noticed is to be careful of leaving salty slush connecting two different metals. For instance many bicycle forks are made out of magnesium, if you leave the bicycle covered in salt-slush there is a chance that a galvanic cell will be made between your fork and the brake bosses of the drop-outs.

Oh yeah, aluminum is awful.. just you wait until we bring up carbon fibre... God save us all, we need to ride around on boat anchors just to be safe!

I bet your roads don't have high blood pressure problem in the winter.

Have you considered a wash-down with fresh water ? every day..

FWIW, Steel ships have sacrificial ingots of Zinc to take on the corrosion.

worked in a shipyard , and fitted a few.

so a practical dip galvanizing would be a lovely finish..

Anodizing the aluminum helps, that is a tank based situation too.