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ClarkinHawaii 02-27-14 08:25 AM

Sun damage to unfinished Chinese carbon fiber fork?
4 years ago I ordered from Hongfu* a carbon fiber frame and fork (painted) and an additional fork (unfinished) that I intended to put on a different bike.

(*as an aside, let me say that I am very pleased with the stuff from Hongfu.)

The specs of the unfinished fork are as follows:

Alloy+Carbon Road Racing Fork (HF-FK022)
Alloy+Carbon Road Racing Fork.
Crown: Alloy.
Dropout: Alloy.
Steerer: Alloy.
Blade: Toray Carbon.
Finish: To order, W/3K.
Weight: 560G+_15g.

I am calling the fork "unfinished" because I did not specify and pay extra for a specific finish. Perhaps it is clearcoated, perhaps not. How does one determine this?

Anyway, all was well until I happened to read recently that sun (UV rays) damage carbon fiber unless it is at least clearcoated.

Since I don't know whether or not it is clearcoated, I am concerned about this possible "sun damage". Is this a legitimate concern? I emailed Jenny at Hongfu to inquire about this; but she hasn't yet replied and may not.

Can anybody give me some straight scoop on this? Would this alleged "sun damage" be just cosmetic, or would it effect structural integrity?

Thanks for your help.

AnkleWork 02-27-14 09:13 AM

Over the life of that fork, how many hours of sun exposure do you anticipate?

ClarkinHawaii 02-27-14 09:36 AM

Well. that depends on the life of the fork. Assuming no accidents, maybe 15 years?? (I really have no idea what is a reasonable life-expectancy for a carbon fork on a non-abused road bike with a 150-lb rider) It's on a Ti frame which should last forever.

Generally speaking, I might ride that bike 180 hours per year; and those hours are usually before 10am.
However, I am in the tropics, and the sun here is industrial-strength.

So guesstimate 2700 hours of midsummer-strength sun.

rpenmanparker 02-27-14 10:55 AM

I would think that the resin formulation is internally stabilized and clear coat is not required. But that is just a supposition. I don't think the manufacturer would sell goods that are not suitable for use.

HillRider 02-27-14 11:04 AM

Unless you can feel the weave of the carbon's outer layer, the fork has a clearcoat of some sort and these almost all have a UV absorber in them. Even at that, the damage from sun exposure is going to be minimal unless you let it sit out all year round all day.

AnkleWork 02-27-14 11:08 AM


Originally Posted by ClarkinHawaii (Post 16531892)
. . . So guesstimate 2700 hours of midsummer-strength sun.

About equivalent to leaving it outside for 250 days. Likely to have a cosmetic effect; structural effect depends on a lot of unknown factors.

ClarkinHawaii 02-27-14 02:55 PM

Thanks, Guys, you've put my mind at ease. Actually the finish looks and feels just like the finish on a very pricey Winwood carbon fiber fork that I have on another bike--I'm going to assume that it's clearcoated and just forget about it.

ClarkinHawaii 02-28-14 10:44 PM

Just received a reply from HongFu; and I'm going to post it here in case somebody has this question in the future:

"Dear Clark,

Thanks for your email.

Don't worry,my friend.the fork is clear coat,UD carbon finish not just has UD finish to protect it.

Any question,please contact us freely.

Have a nice weekend!
Best reagrds,

ultraman6970 03-02-14 07:28 PM

Try to scratch it with your nail, if you can't probably the fork has clear coat over it or probably has that gel thing some manufacturers use.

If you want to play safe just sand a tiny bit and re clear using car polyurethane clear coat, If you want no shiny finish just add a flat agent to the clear, done.

lopek77 03-02-14 07:34 PM

I almost can hear two old aluminum and cro-mo forks laughing now. Nasty bastards!

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