dishing a wheel

[cawright1375]

In another thread I posted a question regarding a headset potentially creating a high speed shimmy/ wobble.

Well my LBS has thrown out that the wheels might need to be dished. Anyway, having never heard of this I googled it and found out what it is. It would seem to me that this might be the issue, if the wheel isn't centered than it would make sense that the faster I went the more it might wobble or give the sensation of wobbling.

Any of you ever have wheels dished? And if so what symptoms did you have before having it done?

 

[DirtyWorks]

In another thread I posted a question regarding a headset potentially creating a high speed shimmy/ wobble.

Well my LBS has thrown out that the wheels might need to be dished. Anyway, having never heard of this I googled it and found out what it is. It would seem to me that this might be the issue, if the wheel isn't centered than it would make sense that the faster I went the more it might wobble or give the sensation of wobbling.

Any of you ever have wheels dished? And if so what symptoms did you have before having it done?

A safe generalization: All wheels are dished.

Checking dish is pretty straightforward, but you need the tool.

The wobble I've experienced I attributed to a steel frame with too many miles on it because the alignment was good.

 

[brianf7]

Your wheel will be dished unless it is an old screw on hub or a track wheel. Your wheel may not be centre and you may have an issue with spacers on the rear axel.

Many things can cause a shimmy seat too far forward too much waight on the bars front fork rake incorrect and possible bent steerer tube Frame alignment there so many issues to name a few. Also your riding style or ability to decend.
Find a good bike shop or better still a frame builder and get them to look at it.

When decending always look as far up the road as you can not looking down on the front wheel. hang your bum over the seat and grip the top tube with your knees

 

[brianf7]

Your wheel will be dished unless it is an old screw on hub or a track wheel. Your wheel may not be centre and you may have an issue with spacers on the rear axel.

Many things can cause a shimmy seat too far forward too much waight on the bars front fork rake incorrect and possible bent steerer tube Frame alignment there so many issues to name a few. Also your riding style or ability to decend.
Find a good bike shop or better still a frame builder and get them to look at it.

When decending always look as far up the road as you can not looking down on the front wheel. hang your bum over the seat and grip the top tube with your knees watch sprinters when they put the arms up in the finish they grip the bike with knees.
A properly balanced bike will steer its self down hills

 

[JayKosta]

For a front wheel, just put the wheel in the fork with the quick release on the other side - with proper dishing the wheel should be centered in the fork both ways.

For the rear wheel, proper dishing puts the rim directly inline with the seat tube and the head tube.

If either wheel has side-to-side wobble, or up-down 'hop', the wheel needs to be 'trued' not dished.

Wheels that are 'true' but not accurately dished, might be difficult to ride 'no hands' (because they would not 'track' in a straight line), but I don't think they would cause shimmy.

Another possibility is if a wheel is severely out of balance. All wheels have a 'heavy spot' (most likely the valve stem), but if the imbalance is great then a vibration and shimmy might occur.

Jay Kosta
Endwell NY USA

 

[cawright1375]

Thanks for the information.

The wheels in question are Bontrager Aeoleus 5.0s. And they were a "rush" order from Trek last year to fill a warranty replacement/ upgrade request and get them to me in time for a charity event I was doing. My thoughts are that as they were a "rush" order than perhaps they had to be built before being sent to the LBS I went through. If that is the case it is entirely possible the rim wasn't properly aligned. And given that the wobble occurs after hitting certain speeds in excess of 40 mph, which I can only do on the descents near my home, I am leaning towards them being out of balance.

The wobble feels like the wheels are teetering if that makes any sense.

And not to sound ungrateful, but if I am posting about descending at speeds over 40+ and describing my front wheel as wobbling and managing to stay upright (knock wood) then I'd hazard a guess that my descending skills are top notch.