Should I be worried about this carbon fork?
I'm giving my Trek 1.7 a good clean at the moment and found that the carbon fork is a bit bubbled around where the alloy steerer is attached.
The first clue was that the front brake is jammed in - it just seems to be furred up inside so won't come out.
You can see in the pictures that the paint is a bit lumpy and in the underneath shot it has cracked and peeled off.
I'm suspicious that's it's just oxidation that has worked its way down under the paint but wanted to see if anyone could confirm this - and that's it's not the carbon delaminating.


If it is just bubbling would it be worth smoothing off the really flaky stuff and then applying a lacquer? Obviously that part is pretty exposed to the elements and there will have been all sorts of muck in there over the last few winters.
Thanks.
The first clue was that the front brake is jammed in - it just seems to be furred up inside so won't come out.
You can see in the pictures that the paint is a bit lumpy and in the underneath shot it has cracked and peeled off.
I'm suspicious that's it's just oxidation that has worked its way down under the paint but wanted to see if anyone could confirm this - and that's it's not the carbon delaminating.


If it is just bubbling would it be worth smoothing off the really flaky stuff and then applying a lacquer? Obviously that part is pretty exposed to the elements and there will have been all sorts of muck in there over the last few winters.
Thanks.
I'm left handed, if that matters.
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Comments
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given the consequences of fork failure it's sensible to be wary, whatever is going on it seems quite extensive
with the wheel out, you can try flexing the fork, squeeze/push the dropouts together/apart to see if any of the cracked/bubbled areas show movement, if they do then it could be time for a new fork
but really i'd consider taking off the bubbly areas of paint, cleaning it up and having a good look
if there's corrosion of the alloy parts they'll expand slightly and seize, it'd be best to remove the brake, acf-50 will neutralise corrosion and may be enough to free things, but if it's really stuck put some plusgas in there and let it seep in for a day or so, then it should be easier to remove
then inspect, repaint if ok, clean things up and re-fit with some anti seize
put a few drops of acf-50 or grease in the hole to protect from spray, every few months wipe out the crud and re-applymy bike - faster than god's and twice as shiny0 -
The bubbling is due to corrosion of the aluminium fork crown - looks like the fork wasn't correctly primered before painting. Treks come with a paint warranty so worth a discussion with your dealer - it's not the first Trek I've seen with rubbish paint. More worrying is that if the aluminium crown wasn't correctly primered, you could get a galvanic corrosion reaction with the carbon fork blades which can lead to structural failure.Make mine an Italian, with Campagnolo on the side..0
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I wouldnt ride them. Doing 50 mph down hill with those is unimaginable.Pegoretti
Colnago
Cervelo
Campagnolo0 -
Had similar on a Bianchi fork, although not that bad.
Sungods advice, although drastic seems the most sensible. Once youve satisfied yourself its ok, prime the rubbed down area and topcoat and varnish.
I assumed (on my Bianchi) that as i'd used it during the winter, salt and crud had settled in the brake nut recess, and it had started from there.
One reason i wont use my good bike for winter riding.0 -
I had nearly the exact same thing with a bike I was renovating - the fork wasn't as bad but I dumped it.
I'm guessing the crown is aluminium, so for corrosion to transmit like that under paint, it'll be salt corrosion (the white flaky stuff) that keeps eating under paint and into the metal (whereas normal oxidization of aluminium halts as soon as the oxidation forms.
I took it to a lot of local shops who all told me not to ride it - though they did say that was more down to liability issues than knowing for sure. The main issue is that the corrosion is around the area that the metal crown is bonded to the carbon. Cleaning the paint off is not really going to 'prove' that the corrosion hasn't gone through to the bonding area which may compromise it.0 -
Well if the fork is shot so is the frame judging by the same bubling on the head tube.
I have similar (not as bad) on my frame (like that when I got it) and I am sure it is purely cosmetic. Water gets under the paint and the Aluminium reacts.Yellow is the new Black.0 -
Thanks, that's all interesting. I took it in to my local Trek dealer and the guy had seen t plenty of times. He was positive it was just cosmetic.
It does look that way but I think I'll pull some of it off and see what's underneath.
The frame is okay - I nearly mentioned that when I put the pictures. It's just a slightly untidy weld and there's dirt in there. The paint there is okay.I'm left handed, if that matters.0