Serious cable corrosion issue. Need help please.
 

My rear brake cable gets completely corroded at least every 4 months. More often if I do a lot of trainer work. I am using SRAM inners as well as outers. I need to change the inner and the rear section of the outer every 3-4 months. Total pain. I live in a dry area, so it's only the sweat.

Any suggestions? Do you get inners which are genuinely corrosion free?

Don't know what sort of set up you have, but if it is the common type with two stops and exposed cable between, try using cable liner between the stops, and grease all of the cable.

This used to be common on MTBs:

https://i.stack.imgur.com/fsu4O.jpg

Use a sweat bra. Google "bike sweat guard". It's a must have if you do much trainer work. It's possible to pretty much destroy a bike with sweat.

Try some stainless cables.

SRAM cables are stainless.

Titanium frame. Can it still corrode?

So, how come they are so badly corroded? Maybe Last couple of times I might not have used a SRAM. Today, I definitely put on a SRAM, so let me see what happens.

Get PowerCordz and the corrosion problem is solved:

https://www.powercordz.com

Are you rinsing your bike off after you sweat all over it on the trainer?

Saran Wrap the area if you can.

I guess it is time for a chemist to join the conversation. :)

The one thing that will attack stainless steel is salt, which of course is plentiful in sweat. My understanding is that the chloride ion interferes with the passivation of the metal surface due to the chromium and nickel oxides. In general salt causes weakening and cracking of stainless steel. Whether it actually causes red rust by facilitating the oxidation of the iron in the steel is another question that I really don't know the answer to.

Deepak, how about telling us what the corrosion looks like.

Not good! The sweat will get under the wrap by capillary action and be held in contact with the cables.

Cables are like $5.

Not the frame, but everything that's steel or aluminum: cable stops, BB, etc.

If you don't want to try a sweat bra you could always use a towel. Attach towel around hoods with rubber bands and used a clamp to hold the towel back behind the seat. That's what I do and it works great.

A word of caution if you sweat enough to cause that much corrosion I would not ride the bike again until I checked the aluminum bars. Especially where the hoods attach. I was shocked when I went to replace my bar tape and the bar was almost corroded all the way thru where the hoods attached. It had only seen maybe a year of use. For this reason I went with carbon bars.

My Ultegra rear shift cable usually frays in 3-4 months. Last time I tried using some Shimano Cable Grease:

https://i.imgur.com/HcxQHx2.jpg

It says "Apply to cables to keep them corrosion free and moving freely in the housing." I haven't noticed a increased lifespan in my shift cables, unfortunately. However it does seem like my brake cable is actually less smooth. Are other people using this to lubricate their cables?

Looks interesting

Nope

Here is a pic. Completely brown/red rust. Edit: Upload keeps failing.

It's the pain of changing.

Saw the Tacx sweat protector but it does not seem to offer protection where I need it the most. I think the fan blows the sweat more over the rear brakes where the protection is the least?

Thanks. I know that possibility. Will keep a look out.

I've spent a lot of time bolting climbing routes near the sea. Even more time climbing other routes near the sea. Let me be perfectly clear. There is no type of steel that won't corrode in the presence of salt, heat, and moisture.

Climbers tried 303, 304, even marine grade 316. They all failed eventually. There is a promising derivative called 1.4601 or something that might work. I promise it's not available in cables. All seaside bolting is now done with titanium, it's safe.

Applying this knowledge to your bike, we can conclude 2 things. 1: There is not a cable material on the market that will resist corrosion under these conditions. 2: Your only solution is the simplest, that is to shield your bike from sweat. (Or remove all cables for the winter).

Makes me want to go back to Thailand.

+1 this. Or ride a single speed or fixed gear on the trainer. No cables to corrode.

Your first and second conclusions are wrong. Powercordz (see post #6) will not corrode, and fitting the OP’s bike with them is the solution.

I didn't realize a synthetic cable material existed until today. I might look into getting some, just fr the cool factor.

How will a winter's worth of salt affect the friction between cable and housing? I still think shielding it is the best bet.

Change the direction of your fan? It could blow at an angle.

Do you wear a Headsweat, Halo or other skull cap? It helps quite a bit.

You could smear the openings of the cable housing and exposed cables with automotive paste wax.

I still think that putting a bit of Saran Wrap around the area before training and tossing it in the trash after each session will help. See post number 17.



-Tim-

Grease won't help if the cable is fraying at the head. The bend the cable has to go through to leave the shifter body is just too extreme. A normal steel cable would last longer in that area, but corrosion in the rest of the housing run might kill it before the head end got enough use to compare the two.

:thumb: Yep. I use a folded over 18 gallon trash bag over the top tube and secure it with zip ties. Then I put a towel over that and the handlebars.

jagwire elite sealed. have not tried them though.

Thanks guys. Lot of suggestions. I applied grease on the areas yesterday. Will spray WD40 every weekend, and I guess wrap the area completely when I am on the trainer.

Yes, I wear a Halo, and still sweat like crazy.

Here is a pic of the cable after just 2 months, and a pic of the area which suffers.

The cable fixing bolt on the brake was completely corroded, and the inside of the barrel adjuster too. Had to scrape them with tools. The barrel adjuster was so bad that I could not even pass a new inner cable.