Unbalanced wheels??

[jalabert]

Hi<br /><br />My wheels seem to be out of balance, meaning that if I spin them they will before comming to a complete stop start rocking back and forth before stopping. This does offcourse mean that they a heavier at the point that ends up at 6 o'clock, which is also where the rim is joint together, but that might not surprise you!?<br />Is it problem that are noticeable during riding?<br /><br />Your help are much appriciated! :-*

 

[Rhodent]

I've heard that this is actually a good thing as it means your wheel is running smoothly on your bearings. Most peoples wheels should settle at the valve if I remember correctly

 

[Mampara]

Mine comes to rest at the computer magnet. I must actually try it without the magnet.

 

[big_h]

Jalabert<br /><br />Yes, the fact that your wheels come to rest at the same point means that your wheel is &quot;unbalanced&quot;. This is in most cases not noticable during riding. (unless your rim had an knock and the wheel is now oval) This you will notice as the wheel bobbing up and down while spinning. As with a wheel that is seriously out of true this can affect the handling and tracking of your bike. In one of the bike repair handbooks that I have they mention that a way to check wether your bearing cones are set to the correct tension is to let the wheel spin when it stops spinning ie starting to rock backwards and forwards the wheel should rock six times. (the last few rocks are almost not noticable in most cases and this is with a fully clamped wheel back between the dropouts of your bike) More and the cones are too lightly set and less the cones are too tight. It is difficult to do on the backwheel as the ratchet on the freewheel stops the motion. You will have to remove the chain for this. Some books also mention that you can start adding counterweights to ensure the wheels are properly &quot;balanced&quot; but they also say that this borders on the ridiculous and that you will be well on the way to become a perfectionist. Remember the action you are talking about in your post above is with a round wheel and the &quot;unbalancing&quot; is due to the factors you noted - the joint on the rim (some of the older wheels were even riveted), the valve and an added item can be irregularities in the tyre itself. THIS IS NOT AN WHEEL OUT OF BALANCE DUE TO DAMAGE.!!!!!! A damaged wheel nust be repaired and trued properly.<br /><br />Keep those wheels spinning!!!!!<br /><br />Big H

 

[jalabert]

Thx for your replies!! <br /><br />The wheels should be true as I had them checked at the bikeshop(only thing on bike that I feel most comfortable not doing myself). About six times back and forth seems right for the front and will probably also be on the back when I replase the rear bearings. This is done without the tyre on, but when it is mounted it still stops the same place even though the magnet is placed same place as the valve(directly opposite to the rim joint). <br />You've convinced me that it's nothing to worry about, so that's great. However you are are welcome to try the little test that started my query in the first place: Lift the front of the bike by the stem and spin the front wheel (almost) as hard as you can. Doing this on my bike results in a very noticable &quot;rocking&quot; up and down of the bike. Is it the same for you?<br /><br />Now that I got your attention you might be able to answer the following without me starting a whole new tread!? I've replaced the grease in my rear ballbearing. Afterwards I wondered(since the wheel didn't spin to well) if I could have added to much grease or is this not possible?<br /><br /><br />

 

[big_h]

Hi Jalabert<br /><br />I normally use the following. If you think there is enough you have too much grease already. I normally smear an amount on the cones, smear some on the inside of the bearing cups, coat the axle with a small amount of grease and coat the bearings with some grease. Too much will work its way out and you will sit with a grease smeared wheel and hub. You will have to place an whole lot of grease to make the wheel slow down. You might have tightened the cones too much. Go to the Sheldon Brown Website www.sheldonbrown.com there should be some tips on greasing a wheel. They also have articles on wheels, trueing and balancing.<br /><br />Keep those wheels spinning!!!!!!<br /><br />Big H

 

[maarten]

Too much grease is no problem it will disappear and only make your hubs a little dirty, better to much then to little grease. As Big_h suggest 9/10 you overtightended the cones, loosen them. Too thight cones result in damage too cones and more important the surface they move in.

 

[jalabert]

Ok, then that's not the problem, so it seems I will have to get me a new bearing and some new balls(yeah yeah, you know what I mean). Don't know if it's normal, but the hub has a sealed bearing in the left side and a ballbearing on the right, which came as a bit of a surprise to me. <br />The cones hasn't been tightened to much as there is just that slight amount of play that I read somewhere there should be.<br /><br />

 

[ant evans]

In motor racing, an unbalanced wheel has an immediate effect on lap times. It may be different in cycling, where there are no cornering forces... but that jiggling motion uses energy, and that energy comes from you. At high speeds (>40kph), I would guess that this would slow you down.

I've never come across this effect on 25mm and narrower tyres. I have noticed it on Vredestein S-Licks... their one weakness, unless you count the brutal ride.