11 replies to this topic Post Order

[Tjommie]

Any advice would be appreciated.

I have a set of 52mm Zefiro carbon clinchers.
The front wheel is buckled and it causes a shudder and vibration when applying front brakes. I used another wheel to check.

I've taken the wheel to 2 reputable bike shops in CT and no one can help me. First shop said the nipple is corroded and they not prepared to take a chance and true the wheel as it may break and they dont have spares.

Second shop tried to true the wheel but its still the same. I called the bike shop again and they said its because the wheel has only 20 spokes and the area between the spokes is too big so they cant do anything else.
I asked if respoking the complete wheel will make a difference and they said no.

Does this now mean the wheel is useless or are there any other options available. Only problem is if i go to another 2 bikes shops they will charge me again


Thanks

[DMC007]

Contact Icycling_Peter Wheeler

http://www.thehubsa....__1#entry217837

[nero123]

I had a similar problem where two shops told me the rim was buckled and that they did the best they could do. The one spoke was always way looser than the other so the wheel immediately went out of true after using it again. But somehow Westdene cycles got the wheel true with all the spokes equally tensioned. Guess it depends on the experience of the wheel builders at those shops.

[Tankman]

carbon clinchers is a biatch to fix!

[Johan Bornman]

You say it is buckled and causes a vibration when you brake. Buckled wheels don't cause vibrations in my experience. You have big beefy dual pivot brakes on there that don't take crap from buckled wheels and they'll just bend the wheel as and when needed - eavh revolution.

Shudders and vibrations come from whimpy brakes like KCNC and, dirt/contamination on the rim brake surface.

You need to confirm for us first if there is run-out on the wheel and if so, where it is. Simply aim through the gap between the brake block and the rim and slowly rotate the wheel. See if the gap comes and goes. If possible, try and confirm for yourself tha the wobble is indeed between two spokes. That would spell trouble like the one bike shop said.

If the wobble is exactly at a spoke, you need to tension the one that will pull the wobble out.

Nevertheless, if it is a vibration you experience, scrub the brake surface with some steel wool or fine sandpaper and wash it clean with a non oily solvent of sorts. Also check the brake pads. Shimano brake pads pick up aluminium from the rim and causes a grinding sound.

Check all this and report back.

Next time, don't buy wheels with

1) Aluminium nipples
2) Paired spokes
3) Low spoke count
4) Names you cannot pronounce when drunk.

[Tjommie]

thanks for the advice

will check tonight and report back

[Tjommie]

The wobble is about 5cm from the one spoke not exactly half way between the two spokes.
I also cleaned the brake surface and the brake pads were replaced last week.

Just to double check i swapped wheels with my other bike which has a mavic aksium and the vibration is gone so it has to be the wheel.

[Johan Bornman]

Hmmmm. Very strange and I can't figure out what it could be. Aluminium rims bend and then display this type of behaviour. They're toast when they're like this.

A composite alu/carbon rim won't bend like that. The carbon will show signs of distress and the aluminium will almost certainly show signs as well.
You report none of this.

If you have a spare wheel, pack this one in a box and send it to me. I'd like to have a look. Otherwise, I'm in Cape Town early October.

I take it you've examined the wheel closely to look for signs of the alu and carbon parting ways?

[TiBones]

Johan, please explain that lacing pattern to me - it looks wild with half the wheel crossing and half not?

[Johan Bornman]

TiBones, on 31 August 2010 - 12:51 , said:

Johan, please explain that lacing pattern to me - it looks wild with half the wheel crossing and half not?

I think you explained it yourself - wild.

I have no clue what's going on there and find it difficult to figure it out from the photo.

[Tjommie]

@JB I inspected the rim and cant see any signs of distress or damage on the rim/carbon part.
I've taken the wheel to one last shop here in CT and they rebuilt the wheel last week. Yesterday i went for a ride and guess what the shudder/vibration is still there. I've gone back to them today and left the bike there so lets see what they say. Will keep you informed otherwise i will have to wait till you come down in October and you can have a look.

I am contantly swapping front wheels to see if its not something else on the bike but its gone when i use another wheel.

TiBones, The spokes do not cross over it only appears like that in the photo, 10 on the left side and 10 on the right side equally spaced.

[Johan Bornman]

Very unusual, although I expect you will eventually stumble upon a perfectly rational reason for the problem. If it still persists by October, I'd like to have a squizz.

What I would do is the following.

1) Mark the problem area on the rim.
2) Release the spoke tension completely.
3) Lay a straight edge along the rim (a brand new unbuilt rim works great) and look for an wobble.

Then make the next decision based on what I find.

Those aluminium nipples (if indeed they are aluminium) won't be a problem. They have headagonal heads and the right tool will not round them off, no matter how tight they are.

Good luck