Front End Rattle

RonnieC

Hi guys, I hope you may be able to offer some advice before I go demented!
I've got a new Canyon CF SLX and whenever I'm going over rough roads (almost all the time in the UK) I get this horrible rattle/chatter noise coming from the bike. Initially I assumed it was a noisy bottle/bottle cage combo, but the noise persisted after removal of the cage.
Lifting the bars and letting go allowing the front wheel to bounce highlights the problem perfectly, doing the same at the rear and it's nice and quiet.
I thought I had isolated the problem as holding the front brake when dropping the wheel down stops the noise entirely. I assumed the caliper was loose, but it's tight. I took it off entirely and the noise was still there.
The headset is tight, skewer is tight and there's no play on the cones of the hub - the wheel feels solid. I'm at a loss as to what the cause is...and it's not a small noise, it's a real head turner in the bunch when the surface gets rough!

Cheers
Ronnie

mattv

Sounds like headset to me. Make sure it has enough headset spacers, in case the steerer is too long and hitting the underside of the top cap.

RonnieC

Yeah, I thought it was the headset too, but it is totally solid. It's an Acros iLock headset so there's no top cap - I had it off earlier and put the tension back on and there's no change (the bikes only 6 weeks old).
The fact the rattle disappears when the front brake is held when bouncing the wheel is the thing that's got me stumped.

dee4life2005

It's not the little nut on the valve for the inner tube by any chance? If you still have this nut on and it's not tight then it can sound a bit like a loose headset.

josehernandez

dee4life2005 wrote:

It's not the little nut on the valve for the inner tube by any chance? If you still have this nut on and it's not tight then it can sound a bit like a loose headset.

This.

RonnieC

No, I don't have them on the valves...I had my hopes up there!
I've put a video of it on youtube, so you can get an idea of the noise.
http://www.youtube.com/watch?v=BA9dWz3K ... e=youtu.be

dee4life2005

It does sound like a loose headset. You say its tight, i'm assuming you've checked for play in the headset bearings by holding the front brake on and rocking the bike?

RonnieC

Yep, doesn't budge - not even the slightest movement. I've got a spacer in between the headset and the stem and that can't spin at all, so it's tight against the stem.

diamonddog

I had a stupid rattle and suspected all sorts of things checked the headset etc, turned out it was the zip tab on my jersey rattling against the buckle on my cycle helmet,what a plonker :oops:

topdude

That is one loud rattle :?
Have you tried removing the front wheel and skewer and bouncing the wheel to see if it rattles ?
Then bounce the frame/ forks on a block of wood to test.
If the noise stays with the frame/forks then stripping out the forks/headset seems the next move.

keef66

Is the wheel fully seated in the dropouts and the QR properly tight?

If it's not that I'd also be suspecting the headset. If there's no back / forth movement detectable it still sounds like you have vertical play somewhere. I'd be stripping it to make sure all the bits are there and in the right order / right way round.

RonnieC

The advice from Canyon was that there was play in the bearings of the front wheel, but I just swapped front wheels on my bikes and the noise stays with the Canyon.
It must be something to do with the headset....I'm tempted to strip it out and put a normal top cap headset on, not like there was even a need to re-invent the wheel in the first place!
Once I regain my composure, the next step is to strip it all down and make sure everything is seated properly.

Thanks

bagz3

would you describe it as more of a clicking sound?

Ben6899

I'm truly intrigued how applying the front brake reduces the noise level.

keef66

Ben6899 wrote:

I'm truly intrigued how applying the front brake reduces the noise level.

That's what made me think it might be the wheel not being securely located in the dropouts; applying the brake stops the wheel moving relative to the forks. Or the caliper's loose and applying the brake stops it rattling. Neither appears to be the case.

Ben6899

Agreed Keef. That's what I would think, given the evidence, but the same happening with another wheel - and after OP has made sure the QR is tight etc - has me very baffled indeed!

dee4life2005

If you listen to the youtube link above then it sounds like the rattle type noise is still there when the wheel is dropped with the brakes applied, it's just significantly dampened.

I had a similar noise recently (though not quite as loud) caused by the compression ring in my FSA Orbit headset not being pushed all the way down. This resulted in a little play in the headset that was fairly subtle (not immediately noticeable using the brake/rocking checking and it created a hell of a racket. Or at least the compression ring appeared to be the cause - hard to tell as the whole headset was removed to check it was installed correctly - and this was the only part that looked like it was fitted incorrectly. The noise was gone when re-fitted.

Could always drop by the LBS and see if they have any suggestions ... if it's an un-usual headset it may be something they've come across before and could have sorted in a minute or two.

RonnieC

Hi guys, thanks for your thoughts. The noise that can be heard when the brake is applied is just the noise of the tyre bouncing on the tiled floor - the rattle totally disappears when the brake is on.
A mate in work has an old steel framed bike with curved fork - when he bounced the front wheel, you could visibly see (and hear) the vibration in the fork. However, when he held the front brake the vibration was totally damped, so the brake does provide extra support when applied to the rim.

I spoke with Canyon this afternoon and they were equally stumped. It's definitely not the brake (it's been removed), it's definitely not the wheel (it's been swapped out) and they don't think it's the headset. However, they are going to send me a new headset and if that doesn't work I have the option of putting it into a LBS at their cost, or send the bike back to them under warranty.

migrantwing

Bizarre! Hope you get it sorted.

Ouija

Sounds like the brake lever itself. From the vid it sounds like the top of the lever is dropping slightly when you drop the bike and then bouncing back up and banging against something. Had a set of mountain bike levers that used to do that until i put a bit of sticky backed acoustic foam in there to dampen it.

Try squeezing the brake caliper manually against the wheel with your fingers and then drop it and see if it still rattles. If yes, it's the brake lever, if no it's something else. Could also be the cable inner rattling when not under tension.

Ben6899

Ouija might have a point (or a couple of points)... if it is either of these, then I'd bet the brake lever. Cable inners rattling is usually a more tinny sound.

RonnieC

I've finally got to the bottom of it!
It's definitely related to the headset. I was able to the tighten the headset further and with every turn of the grubscrew, the rattle reduced. It would seem that it was tight enough to eliminate any movement when rocking the bike back and forth with the brake on, but not tight enough to prevent vertical movement of the fork in the head tube.
There is a problem with the headset however, so I'm waiting on a new headset coming from Canyon which I am sure will totally fix the problem. Now that I have had the headset apart again and had a proper look, it's obvious to see what's wrong - but difficult to explain!

Here's a youtube link of how the headset should work...
http://www.youtube.com/watch?v=kVHiQSnrq0o

There is a steel pin in the top part of the headset which the grubscrew pushes against and turns (expands) the headset. What's happening with mine is that when the grubscrew is part way in, the pin that it's pushing is loose and moves to the side and the grubscrew squirms to the side and nothing is really holding it in position.
Easy to see...hard to explain!