Should I be worrying about fork damage here

brownian

Just noticed that my carbon forks seem to have been eroded a bit by my mudguard - there's a groove about 2-3mm deep worn on one side, and another, maybe half as deep, on the other.

Are my forks going to snap as I tear down some hill...or is this just cosmetic?

Thoughts?

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Andy Magic

I wouldn't be, i have similar marks on one of my bikes from the new tyre thread at teh sidewalls

not sane

Is that a chunk missing from the left hand side

brownian

not sane wrote: »

Is that a chunk missing from the left hand side

Yes - there's a bit of a nick on the left hand side. Quite clear in the 3rd picture. But the groove on the R is both taller and deeper - quite clear in the 2nd shot.

queldy

No, no worries.

Wishbone Ash

I have the same marking on two of my bikes. I presume it's caused by the frame flexing when out of the saddle forcing the wheel/tyre towards the forks?

ford2600

I retired a fork with similar damage; do you want a doubt in your head when applying brakes on some descent at 70km/h?

Bring it to a good lbs and see what they think maybe?

"this grand" of some random user on internet isn't worth much without knowing if the structural integrity of fork has been compromised or not

magicbastarder

Wishbone Ash wrote: »

I have the same marking on two of my bikes. I presume it's caused by the frame flexing when out of the saddle forcing the wheel/tyre towards the forks?

i have similar marking on my fork too. it's been there for over a year and hadn't gotten worse last time i checked, but must check it again.

not sane

Great thing about carbon it can be fixed, and knowing personally I'm a stickler for my forks. They go your on your knoggin. Not nice just ask the guys who rode alu forks in the 80's. If you have a doubt replace.

brownian

Thanks all. Will ask my LBS when next there (soon, as it happens).

Wishbone Ash

brownian wrote: »

Thanks all. Will ask my LBS when next there (soon, as it happens).

The problem with asking your LBS is that they tend to err on the side of caution to avoid repercussions (which is perfectly understandable).

saccades

From a Mtb and carbon canoe builder background.

They are borderline dump, you have gone through the cosmetic layer into the layup. At what point they will go is anyone's guess but probably when you don't want it. It's in an area of the bike where failure is going to really hurt, a chainstay and I'd keep going but not there.

I have 12-22 year old Mtb carbon forks covered in scratches and wear marks but all are in the cosmetic layer only so I'll keep using

All I can heavily recommend to anyone similar is leading edge/helicopter/frame tape where ever 2 parts might rub road grit to wear away the bike (cables are famous for this).

secman

Must check my own carbon forks, 2 should be fine as they are relatively new, but one set is on a Caad 9...

magicbastarder

saccades wrote: »

They are borderline dump, you have gone through the cosmetic layer into the layup.

hmm; i'm 90% certain mine are also through the laquer or whatever the surface finish is. and the manufacturer doesn't list replacement forks on their website, must ring one of the dealers here to see if they can be ordered in and what the cost would be.

magicbastarder

here's mine - as you can see from the photo, it's just where the carbon meets the metal crown of the fork (it's an alloy steerer). there was protective tape there too, but as you can see, that helpfully fell off.
the main cause would be that the mudguard had become rattly; on the bracket it was riveted to to attach it to the crown, the rivets had come loose but stayed captive, so it'd bounce around on rough roads.

should i see a carbon weave where it's gone through the surface coating? to my untrained eye, it looks more like a resin.



the other side is fine - the tape stayed in place.

not sane

Was just wondering whether it was trolls or not. But geez lads I'd take out life insurance if your gonna ride stuff like that.

magicbastarder

yeah, the photo makes it look like it's several mm deep, it's about 1mm at its deepest. hopefully the fact that it's where the carbon and alloy meet mean that it's nice and beefy there.
will bring it to the shop and ask.

not sane

Wasting my breath.