oisiaa

I just bought a Trek 1.1. The manufacturers website specifically says that it has an aluminum fork, but mine has a sticker on the fork that warns about the dangers of carbon. What's the deal?

To my untrained eye and ear it does in fact look like a carbon fiber part. It doesn't sound like aluminum when tapped and the shape looks too fluid and seamless to be aluminum. Perhaps Trek upgraded this model to a carbon fork without updating their website?

Any insights?

vw addict

well aluminum and carbon have very distinct sounds, that should be your answer.

RonH

Looks like carbon to me. You could scrape off some paint to be sure.

oisiaa

I haven't interacted with a carbon fork or really any carbon fiber part before, but this fork definitley doesn't sound like aluminum to me. It doesn't hurt my feelings either way, I'm just curious.

oisiaa

It's aluminum. I can see some unpainted parts where the axle attaches. I wonder how/why that carbon warning sticker is on there?

operator

Carbon bladed forks can still have AL dropouts.

oisiaa

Well, now I'm confused. Like I said, the fork itself definitely doesn't sound like any metal I've heard before....is there any non-destructive test I can perform? I don't think I have the ability to do an eddy current inspection or anything like that.

fa63

Most likely the legs of the fork are carbon fiber; the steerer tube and the dropouts (where the skewers go) are aluminum.

iam7head

try not email your trek reps for a fast response.

they took care of my problem, all you need is the serial number and they can tell

you exactly what it is.

well, unless you got the bike used or from some fishy LBS(part swapper)

7bmwm3gtr

Maybe the dealer thought the fork was carbon, and put that sticker on.

mzeffex 

You could always take the fork off and see if the aluminum (no doubt) steerer tube is welded on or kind of stuck in. Or even just look up at the fork from above the wheel (meaning look on the inside of the fork where the brake bolts on) and see if you can see the weld or not weld there.

jdon

From the same site:

"We reserve the right to make changes to the product information contained on this site at any time without notice, including with respect to equipment, specifications, models, colors, and materials."

paste_me

trying tapping the frame and then the fork, carbon almost feels like you are tapping plastic and does not have that chime sound that the frame would have

oisiaa

That is pretty much how it sounds. I tried tapping on other structural members and they sound distinctively different.

Thanks for the help everyone. I'm still not 100% sure, but that is okay.

ridethecliche

Why don't you just post a picture here?

oisiaa

What do you want a picture of? I posted one in my first post. Just let me know the angle and I'll take one.

WhyFi

It's carbon - next!

Gluteus

Hit it hard with a hammer.
If it breaks in pieces, it's carbon.
If it bends (and maybe cracks) it's aluminun.

BengeBoy 

Try riding it. If it explodes, it's carbon.

BengeBoy 

Ha - you beat me to this.

NMatt30

Hi oisiaa,

I just found this thread about your Trek's suspected carbon fiber fork. I recently purchased a 2011 Trek 1.1 and today noticed the exact same sticker on my bikes fork. I was wondering if you ever determined for sure if your fork was aluminum or carbon. Like you I was assuming my fork was aluminum based on the manufacturers specs. It's a great bike either way but I had been amazed at how light the bike was and am now thinking perhaps that could help explain the weight, and why it seems to ride so smoothly over rough roads.

Thanks

datlas 

It doesn't matter!

It's a bike. Ride it.

Ride more, worry less.

Runner 1

If you're riding and it explodes, it's carbon. Otherwise, it's aluminum.

I was going to tell you to use Lenz's law and see if you can feel the resistance of moving a neodymium magnet over the fork, but I just tried it over the aluminum downtube on my bike and the resistance force is negligible enough that I can't notice it.

SlimRider

Find something solid and aluminum, like a somewhat long (about a foot or so) aluminum door frame, threshold, etc. Now also, find a plastic comb.

Ok great! Now get a metal spoon.

Place the tip of the solid aluminum object to the floor. The tip of the aluminum just touches the floor. Now tap the aluminum with the back of the spoon. Listen intently to the sound. Remember that sound. It should be like a "ting".

Now place the tip of the comb to the floor. Now tap the comb with that same spoon in the same manner that you tapped the aluminum. It should make a dull "tick" sound.

Now tap the fork of the bike. If it "tings" its aluminum. If it "ticks" its carbon.

- Slim

ultraman6970

Wack it with a screwdriver, if you see sparks coming out it is AL, if some black pieces of plastic come out then is carbon.