Posts
25
Joined
4/25/2021
Location
Mars, CA
US
Anybody have anything like this happen to their Spank rim, or any aluminum rim for that matter?Been on these rims a few years and just now converting to tubeless. Took off the original rimstrip and found some strange corrosion around the valve stem hole. It is on both front and rear. Not sure what is causing it. 
Holy cats! The only thing I've seen that can do that to aluminum is a salt. Regular NaCl might not do it, but CaCl or MgCl may be more potent. I've seen pitting like that on the alloy crown of a carbon fork, and plenty of spoke nipples. Do you ride the bike in an area that salts the roads in winter?
Yeah thats what I think is strange is that I live in SoCal so no salted roads to be had here. Maybe out riding in Laguna and the air is salty I guess but I cant imagine it would be that salty down there unless right on the beach. Weird that is only on the valve stem and only on the inside of the rim. Maybe because whatever got in there just stayed in there? Versus anything on the outside of the rim would most likely be cleaned everytime I rinsed the bike off.
What are you washing the bike with ?
I dont use any soap or spray down with a hose or anything like that. Bike stays fairly clean, I just use Isopropyl alcohol on a rag to keep everything fresh. Its got rained on a couple times out on the rack on back of my truck so thats the only times it has been fully soaked. Those times I just dried it off with a towel and stashed it in the garage. When I said rinsed off I should have specified that I just wipe down with iso on a rag. Its strange because I have other sets of wheels that all get the same treatment and only these have the odd corrosion.
What kind of valves?
Can be galvanic corrosion, and if there is a steel valve and aluminium rim this can happen.
Hmm maybe there is something to that. Interesting. Using Continental 26” freeride tubes. Unsure of the valve stem material. Also I use these tubes on my other wheels and have not see any corrosion. Maybe Spanks specific alloy is more susceptible to the galvanic corrosion.
Living in the winter salted north I've seen it as a result of roadway deicers (beet juice eats AL up fierce), but I've also seen it in parts from coastal regions, mostly Gulf and East coast regions. Those cold waters of the Pacific likely aren't at play here though. I'd ping Spank and see what they know. Since it looks to be isolated to the valve hole does look to be a material compatibility issue between the valve stem and the alloy.
Alright thanks everyone for all the info ill follow up with Spank soon and see if it is something they have seen or know a little more about. Appreciate you guys
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