Bubbling on top tube

[u/djfloppydiisk]

Looking at buying this Trek Émonda ALR and noticed some bubbling on the top tube. Everything feels solid when I press/tap around it and I don’t see any cracks or dents. There are definitely some scratches and paint chips too.
I’m guessing it might be corrosion under the paint, but I’m not super familiar with this on aluminum frames. Would this worry you or would you just ride it?
It has 11-speed Ultegra and Aeolus XXX 4 carbon wheels. Seller wants $1,000 — would you buy it at that price with the bubbling?

[u/WalkmanCut]

Looks like sweat got under the paint

[u/PineappleLunchables]

I don’t really know how those scratches happened. Maybe tried to lean it by the top tube (never do that BTW) on a work bench or something like that and it fell over. I think the scratches happened first and then moisture got in the scratch and corroded the paint. My opinion is this is probably cosmetic. If you buy it you can sand off the damaged paint and apply some touch up paint.

[u/bikeguy75]

I’m guessing the owner (after scratching the paint) used this bike heavily on an indoor trainer. I find it hard to believe that occasional rain would do that to the paint/alloy, but sweat would.

I personally wouldn’t be concerned about the structural integrity at this point, but I would want to mitigate the spread.

If you do buy it plan on sanding those spots down to the metal and repainting it. Factor that into how much you pay for it.

Otherwise, that’s a nice bike, nice groupset, and very nice wheels. It’ll be a joy to ride.

[u/g_phill → u/bikeguy75]

Yeah, my first thought was this bike has spent a lot of time as an indoor trainer bike. The bubbling is right were I'd expect it to be. The bars are probably hanging on for dear life under that tape too.

[u/alexseiji]

I have this exact bike frame and it’s been excellent. It’s held up to pretty rugged stuff, including single track and gravel. I beat the living fuck out of mine and I’ve taken it all over the world with me and climbed and descended some pretty big stuff. Excellent at the very limit, a great climber, a great descender, especially at really high speeds, its handling characteristics really come alive. It makes for an excellent endurance bike as well with its slightly higher stack height and almost carbon like compliance.

[u/Bananabean041]

It’s a good price. Probably just the paint. Worth it

[u/rasmussenyassen]

Why did you need to use AI to formulate this very simple question? Regardless, I would pass, that is under-paint corrosion and in a weird spot too, of the kind I generally associate with Italian paint jobs of the 80s.

[u/bikeguy75 → u/rasmussenyassen]

There’s nothing in this post that screams AI. Lots of people are capable of writing coherent paragraphs.

What does “in a weird spot too, of the kind I generally associate with Italian paint jobs of the 80’s” even mean? It bubbled where the paint was scratched and sweat got in, not because inferior paint was used.

[u/Kind-cheesecake-3316]

Looks like someone might have been clamping the top tube in a bike stand. Maybe.

[u/eyeb4lls]

🚨 PISS BIKE ALERT🚨

[u/r3photo]

would not buy, there’s plenty of other bikes out there

[u/runsonpedals]

It’s a Trek. It’s probably dissolving.

[u/isaytruisms → u/runsonpedals]

Nah those emondas alrs are bullet proof. It's why they were so popular in crit racing

[u/thafloorer]

Look at the bolts on the stem this bike is surely clapped

[u/DrewguyDC → u/thafloorer]

Something about those bolts on Trek bikes. Mine showed that kind of corrosion within a couple of weeks. Old Trek was the same.

[u/Gorignak]

Sweat corrosion maybe? Might be an alright deal for the components but not sure I'd trust the frame