Re: Could This Be Loose Headset?

[Elisa Francesca Roselli]

My gearhead colleague has just had a look at the bike here beside me. He
thinks the front wheel is slightly warped. When I hold up the bike and
spin the wheel, it oscillates slightly on the left side. He says that at
25-30 km an hour, Flyzipper's speed on the downhills, this could expand
and become perceptible as a wobble. He says one good bump on a road
could warp a wheel like that. He also thinks the cheapest and simplest
solution is probably to change the wheel. There is also a subtle and
very expensive art of wheel balancing that consists in delicately
changing the tightening of the spokes, but that is probably not
accessible to me.

What do folks think here about warped wheels and shimmy?

EFR
Ile de France

 

[Tim Hall]

On Mon, 04 Apr 2005 09:07:41 +0200, Elisa Francesca Roselli
<[email protected]> wrote:

>My gearhead colleague has just had a look at the bike here beside me. He
>thinks the front wheel is slightly warped. When I hold up the bike and
>spin the wheel, it oscillates slightly on the left side. He says that at
>25-30 km an hour, Flyzipper's speed on the downhills, this could expand
>and become perceptible as a wobble. He says one good bump on a road
>could warp a wheel like that. He also thinks the cheapest and simplest
>solution is probably to change the wheel. There is also a subtle and
>very expensive art of wheel balancing that consists in delicately
>changing the tightening of the spokes, but that is probably not
>accessible to me.

Take the wheel into a bike shop. They'll have the skills and tools
needed to "unwarp" it. Here in the UK such a service costs about 10
pounds, much cheaper than a new wheel.


Tim

 

[Tony Raven]

Elisa Francesca Roselli wrote:
> My gearhead colleague has just had a look at the bike here beside me. He
> thinks the front wheel is slightly warped. When I hold up the bike and
> spin the wheel, it oscillates slightly on the left side. He says that at
> 25-30 km an hour, Flyzipper's speed on the downhills, this could expand
> and become perceptible as a wobble. He says one good bump on a road
> could warp a wheel like that. He also thinks the cheapest and simplest
> solution is probably to change the wheel. There is also a subtle and
> very expensive art of wheel balancing that consists in delicately
> changing the tightening of the spokes, but that is probably not
> accessible to me.
>
> What do folks think here about warped wheels and shimmy?
>

Possible but unlikely unless its gross. When you say it oscillates on
the left hand side, it should be equal on both sides unless its the tyre
that slightly distorted or badly seated.

Truing a wheel is not hard provided you are methodical about it.
Sheldon Brown's website will take you through how to do it and you can
do it with the bike upside down and using the brake pads as indicators.
There's a lot of extra stuff included on the site about building the
wheel and dish and tension that you can ignore and just use the truing
stuff.

http://sheldonbrown.com/wheelbuild.html#tensioning

Tony

 

[[email protected]]

Elisa Francesca Roselli writes:

> My gearhead colleague has just had a look at the bike here beside
> me. He thinks the front wheel is slightly warped. When I hold up the
> bike and spin the wheel, it oscillates slightly on the left side. He
> says that at 25-30 km an hour, Flyzipper's speed on the downhills,
> this could expand and become perceptible as a wobble. He says one
> good bump on a road could warp a wheel like that. He also thinks the
> cheapest and simplest solution is probably to change the
> wheel. There is also a subtle and very expensive art of wheel
> balancing that consists in delicately changing the tightening of the
> spokes, but that is probably not accessible to me.

> What do folks think here about warped wheels and shimmy?

Shimmy occurs at a frequency unrelated to single wheel rotations and
does not arise from wheel unbalance or alignment. This sort of
specious guess is tossed out often here on wreck.bike. Don't be
swayed by such claims, ask for proof. For instance have your expert
install the wheel in his bicycle and demonstrate that it is caused by
that wheel and not by the one he usually rides.

[email protected]

 

[Pete Biggs]

Elisa Francesca Roselli wrote:

> What do folks think here about warped wheels and shimmy?

Plenty of cyclists ride around with out-of-true wheels and no shimmy.

~PB

 

[Leo Lichtman]

"Elisa Francesca Roselli": (clip) What do folks think here about warped
wheels and shimmy?
^^^^^^^^^^^^^^^
Almost any "gearhead" cyclist with a spoke wrench should be able to reduce
the wobble in about 15 minutes. Even if it's not the source of the problem,
it's worth doing. I certainly wouldn't replace the wheel at this point.

Jobst's comment is pertinent: If the wheel is not true, it is going to make
a wavy path on the road--it is not going to shake the bike.

 

[Claire Petersky]

"Tim Hall" <[email protected]> wrote in message
news:[email protected]...

> Take the wheel into a bike shop. They'll have the skills and tools
> needed to "unwarp" it. Here in the UK such a service costs about 10
> pounds, much cheaper than a new wheel.

My wrench will do it for free. I've dumped so much money at the shop, I
guess they don't worry about a quick job like that.


--
Warm Regards,

Claire Petersky

Personal page: http://www.geocities.com/cpetersky/
See the books I've set free at:
http://bookcrossing.com/referral/Cpetersky