Are these forks safe?!

nom de plum

I might be a bit paranoid, but whilst fitting some new brakes, I notice this "corrosion"
http://flickr.com/photos/16682367@N00/2 ... 4/sizes/l/
(I think that's what it is) on my ITM Millenium forks. They are about 2 years old and have not been in any accidents.
do you think this is normal and safe
Thanks in advance
Steve

fossyant

I'm assuming that 's an alloy crown on carbon forks - can and does happen - it's just the alloy oxidising - It sort of self heals - i.e. the corrosion wont get worse, but may travel, but doesn't look too pretty give it a light sand and touch it up so it looks neater.

simbil1

How is it if you prod it - is it just right on the surface? Is that a crack near the join with the headset?

Aluminium bonded to carbon can be susceptible to cathodic oxidisation so it needs protecting from the elements unlike normal aluminium.

sps137

as Fossyant says that's just the way alloy corrodes, it should be surface only as the newly formed oxidation provides a protective surface for the metal underneath, unless you can see a crack I wouldn't worry.

simbil1

You cannot rely on Aluminium's oxide coat when it is subject to galvanic oxidisation. You need to separate it electrically from the carbon or coat it so that galvanic oxidisation cannot occur.

If you are not familiar with galvanic oxidisation you can learn about it here:
http://aluminium.matter.org.uk/content/ ... 2144416692

nom de plum

simbil1 wrote:

How is it if you prod it - is it just right on the surface? Is that a crack near the join with the headset?

Aluminium bonded to carbon can be susceptible to cathodic oxidisation so it needs protecting from the elements unlike normal aluminium.

Thanks for the replies...its appears to be superficial and there's no cracks. I'm doing a long ride on Sunday so I'll find out if they are up to the job or not!!!

Bugly

looks to be corroding under the paint finish' if you look to the upper right. My concern would be that it is around the brake bolt and personally I would not like significant weakening around that area. The corrosion looks to be reasonably deep and wide spread. Is there any corrosion on the inner surface or the steering tube? If so I would bin it if not I would most likely bin it anyway. I have seen forks shearing at the crown during a race = impressive to the onlooker but brown stain worthy for the rider.

Ultimaltly your skin you choice - but you would get better advice from someone with experience working with alloys doing a visual or preferably ulltrasound inspection.

synchronicity

I used to work in the field of Materials Science.
I imagine that an ultrasound inspection etc would probaby cost more than a set of new forks. They look alright to me though.

pedalrog

If you value your life and the lives of your cycling companions, I would err on the safe side: bin them and get some new ones. Ask anybody who has experienced fork breakages.