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Disclaimer: no formal training in the topic, just curiosity got the better of me:
Using this corrosion rate calculator, and these parameters:
-In one image, I count 15 pinholes on a roughly 20x3cm area (accounting for it being a curved surface, so ~6000mm2, but thats a guesstimate)
-Each pinhole is ~0.5mm2 (at least?)
-Colombus Zona is 25CRMO4, and has a density of 0.00775 g/mm3
-Middle of top tube is 0.5mm thick, for sake of simplicity Im ignoring curvature and calculate each pinhole as 0.25mm3 material removed. Times 15, times density: 29.06mg metal weight loss
-Frame is 6 years old, we'll assume proper storage of materials before buildCorrosion rate comes to 104.1 micros/year, which is categorized as very high, with this definition: Coastal and offshore areas with high salinity. Buildings or areas with almost permanent condensation and high pollution. Does this describe your home? :)
All this is armchair engineering though, tester will come in a minute and put me in my place. But anyways, tubes look very clean from the inside.
Edit: frame is 7 years old, my bad. Wont recalculate, but you get the point.
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kiskubai
So frame arrived late last week and was in a pretty sorry state for itself considering i'd sent what I thought was a good condition frame off for a respray.
The top tube in particular is covering in small holes and on the rest of the rest of the frame mainly around the welds there are small pin holes coming through .
I picked up a cheap endoscopy camera (much to my partners horror) and was pretty shocked with how rusty the top tube and down tube looked considering the seat tube, bb area and head tube area were fairly clean.
In contrast i've never looked inside steel tubing so uncertain whether this is standard wear and tear for a bike of this age / usage.
Assuming in light of the inside of the inside of tubes this was not caused by the spray shop. I've not managed to get any form of the reply from the frame maker which is disappointing, however assume they'll be no way of me getting it repaired under there "warranty" as I can't prove the frames usage, storage condition etc.
If anyone else has any other advice, thoughts etc would be great to hear it.
I've owned quite a few junk steel bikes over the years that have been treated far worse than this and never had any issues so this has been pretty disheartening considering the time, cash that went into the bike.