Road Cycling - My carbon forks make an odd noise.

I did a (very) quick search of previous posts but didn't turn up anything about this, so I thought I'd ask.

I've just got a new alu road bike with carbon forks and I find that if I go over a bump without really shifting my weight back the forks make an odd clanking sound - it sounds kind of ceramic - do any of you get the same thing?

Cheers,

Jonny

PS and yes, I do normally get my weight further back, but sometimes the bumps hide in wait for you.... ;)

Is the fork loose? Can you wiggle it back and forth? Stand over the bike, grab the handlebar and see if you can wiggle it...has it always done this?

otherwise, take it to the bike doctor...

Used to be a mountain bike doctor myself, so I'm fairly confident that the aheadset is preloaded tightly enough. The sounds were on my first ride and over a very specific kind of bump; namely the edge of drain covers at very edge of the road. My commute forces me to go over at least a few of these and they tend to be very sudden. Since my first post I've had the chance to sneak in a cheeky 10K and didn't hear the noise at all (including going over various speed bumps and off a kerb or two).

I'm left with two conclusions:
1) It will always happen so don't cycle over drain covers.
2) It was just the (brand new) forks bedding in a little bit.
3) The forks are duds (but they perform as expected in all other regards)

I'd be very interested if you have any other ideas.

Jonny

Why are you so certain that it's the fork?

hmm, now that I think of it, my carbon-forked bike makes a very different sound then my steel-forked bike when going over big bumps like potholes that I don't see or train tracks. the carbon-forked bike is sort of a thud-clink sort of sound, the steel bike is like a boing/bell resonating sound. The carbon fork makes a softer noise. I think that the clink is one of my cables hitting the frame, but I can't be sure.

hmm, now that I think of it, my carbon-forked bike makes a very different sound then my steel-forked bike when going over big bumps like potholes that I don't see or train tracks. the carbon-forked bike is sort of a thud-clink sort of sound, the steel bike is like a boing/bell resonating sound. The carbon fork makes a softer noise. I think that the clink is one of my cables hitting the frame, but I can't be sure.

I just got a new bike with carbon fork, and had the same observation you did. Picking up the front end a couple of inches and dropping to the garage floor, you can really hear and see a difference in the stiffness and damping. As you said, the steel fork/frame will "boing" for a second or two, while the carbon (Ouzo Pro) vibrates much less and damps out quickly.

Also hear cable clinking over bumps. Believe it's the STI cables hitting where they overlap. I'm going to try a little spacer or rubber band between them. My old steel bike has downtube shifters and internal routing, so I'm not used to those wires running everywhere.

does your carboin fork come w/ a carbon steerer..

I noticed a kind of creaking sound on CFs with Alu and CrMO steerers. But those full Carbon Cfs are silent. :)

Thanks for all the feedback.

I spoke to one of my old friends from college, he used to work for a carbon fibre fabricating company and as a leaving gift they gave him a carbon fibre pool cue which makes a *very* similar noise when you hit things with it. He claims that it is the normal noise that carbon makes when hit hard.

I guess I'll have to avoid any sharp bumps. On my ride to work this morning there was only one that I couldn't steer around, so I hopped it; :) glad I grew up on MTBs.

Still interested to hear anyone else's experiences with the carbon...

Jonny

It seems carbon is like the ceramic from a tea pot ..
whack it strong enough, and you can shatter the fork.

For safety, I prefer cromoly steel ...at least it will
bend before it breaks ! Even aluminum will take a
massive amount of damage before breaking ... unlike
carbon.

However, I get the feeling that titanium is kinda easy
to bend,

I recently (2 weeks), bought the Profile BRC Carbon Fork, Now Im afraid of my fork :S Imagine, if the fork breaks, I'll be flying like a bird :S

The first carbon fork I ever used, creaked like heck. It had a threaded steerer so that cancelled out any chance of looseness. I checked the headset bearings, they were OK too. I checked the fork tips, that they were solid. No problem there. Still couldn't work it out. So, I stpipped out the fork, took off the computer sensor and brake caliper, packed it up and sent it back to the manufacturer to get checked. They found nothing wrong. I fitted it back in the bike. i went for a ride - creaking gone! Went home, fixed the computer sensor (Sigma) and went for a ride the next day. The creaking was back! It was the computer sensor! A bit of inner tube cut to size and stuck on the back of the sensor cured the creak. I now do this as a matter of course with each new fork or computer.

A friend of mine had the same problem, but this time it wasn't the computer. He smeared a thin film of grease on the axle locknuts and this cured his creaking.

So don't panic, the noise might well be from something insignificant that you hadn't thought of.

The first carbon fork I ever used, creaked like heck. It had a threaded steerer so that cancelled out any chance of looseness. I checked the headset bearings, they were OK too. I checked the fork tips, that they were solid. No problem there. Still couldn't work it out. So, I stpipped out the fork, took off the computer sensor and brake caliper, packed it up and sent it back to the manufacturer to get checked. They found nothing wrong. I fitted it back in the bike. i went for a ride - creaking gone! Went home, fixed the computer sensor (Sigma) and went for a ride the next day. The creaking was back! It was the computer sensor! A bit of inner tube cut to size and stuck on the back of the sensor cured the creak. I now do this as a matter of course with each new fork or computer.

A friend of mine had the same problem, but this time it wasn't the computer. He smeared a thin film of grease on the axle locknuts and this cured his creaking.

So don't panic, the noise might well be from something insignificant that you hadn't thought of.


I was having the same exact problem with my Winwood carbon fork. One day creaky next day not. I had thought it was an overtight stem or headset, NOT.
I found it just last night, it is where the cable enters the downtube cable stop. Everytime the bars were turned (either direction) it made this horrible "grind,moan,schreeching" noise.

Last weekend I was on my club ride and a guy that was going at the same pace up a hill said "What the hell is that noise???". I felt like a dumb-ass cause I didnt really know and told him it was an overtightened stem.

So I agree with the statement above about not assuming you know exactly where the noise is originating from. ;)

Could the noise possibly be caused by cables smacking your frame somewhere? They may not make contact until a sufficiently hard jolt.

Since they're carbon fiber, it means that the forks will probably collapse at any moment.

Steel or aluminum forks are the only way to go.

Interesting... I just got a computer and it makes a noise every time the sensor comes up to the receiver.

The computer was fine on my bike with steel forks but could the carbon forks be the problem?

It seems carbon is like the ceramic from a tea pot ..
whack it strong enough, and you can shatter the fork.

For safety, I prefer cromoly steel ...at least it will
bend before it breaks ! Even aluminum will take a
massive amount of damage before breaking ... unlike
carbon.

However, I get the feeling that titanium is kinda easy
to bend,

I think you need a short course in material science and a primer in how carbon fibre materials are constructed.

Carbon fibre frames and components make great resonators. You're riding a very expensive speaker box. :D The noise can originate from many places yet get transferred around by the carbon fibre structures. This can produce a deceptive soundscape.

Carbon fibre frames and components make great resonators. You're riding a very expensive speaker box. :D The noise can originate from many places yet get transferred around by the carbon fibre structures. This can produce a deceptive soundscape.

That's true. The frequency is travelling through the outer layer and bouncing around in the fork. I'm going to try and insulate it with a layer of rubber or something.

Interesting... I just got a computer and it makes a noise every time the sensor comes up to the receiver.

The computer was fine on my bike with steel forks but could the carbon forks be the problem?

U sure it's not the mechanism inside the receiver clicking on the speedo?

U sure it's not the mechanism inside the receiver clicking on the speedo?

That's most likely it. Most wheel sensors use a reed switch or something similar and they tend to make a small bit of noise when actuated by the magnet.

That's most likely it. Most wheel sensors use a reed switch or something similar and they tend to make a small bit of noise when actuated by the magnet.

It didn't do it on my other bike (same computer). I just took it for a ride and can't even hear it. Problem solved.

It didn't do it on my other bike (same computer). I just took it for a ride and can't even hear it. Problem solved.

The other possibility is that you have your magnet spaced really close to the sensor and the slight flex in the fork legs or the wheels may be enough to cause them to make a brushing contact.

The other possibility is that you have your magnet spaced really close to the sensor and the slight flex in the fork legs or the wheels may be enough to cause them to make a brushing contact.

It does it if I'm riding it or not.

It seems carbon is like the ceramic from a tea pot ..
whack it strong enough, and you can shatter the fork.

For safety, I prefer cromoly steel ...at least it will
bend before it breaks ! Even aluminum will take a
massive amount of damage before breaking ... unlike
carbon.

However, I get the feeling that titanium is kinda easy
to bend,

What the crap does this have to do with anything in this thread??? :rolleyes:

And FYI, carbon doesn't "shatter".

It does it if I'm riding it or not.

You sensor makes a clicking noise even while stationary? What computer is this?

You sensor makes a clicking noise even while stationary? What computer is this?

When stationary, as in bike not moving, if the wheel's still spinning, it'll click.
If however, nothing's moving and your bike computer's making a clicking noise... run, she's gonna blow!

Sounds like your head set is loose.....have it checked.

Sounds like your head set is loose.....have it checked.

The headset is not loose. When the wheel spins (when I'm on the bike or not), it makes a resonance noise. It didn;t make the noise before I put the computer on and the computer didn't make this noise on my other bike. The sensor os not touching the magnet. It definitely has something to do with the carbon fork. Somehow the frequency is getting into the carbon and bouncing off the inside.

I can't hear it when I'm riding so it doesn't matter anyway. I was just curious.