Lateral adjustments

[erdem]

hello. i am a complete newbie. i haven't trued a wheel by myself yet . i plan to true wheels my self when i have necessary tools. (like a truing stand and a spoke tension meter etc..) especially i learned a lot from this site. (thanks alex and others)

i read something about wheel truing but i am not sure whether i understood the issue correctly. so i decided to ask you.

let's assume that this is our rim. on the left side there are A, C, E and on the right side there are B,D and F nipples.



if caliper is rubbing left between the dotted area (which is opposite of a right-side spoke) than what we need to do is tightening the D nipple 1/2 turn clockwise.



and if there is a rub (again left side) between two right side spokes (dotted area) first we check the right side spokes tightness. if one of them is looser we tighten it 1/2 turn else if they seem equally tight then we tighten them both 1/4 turn.

for lateral adjustments all we need to do is this? else are there any other situations (i don't mean when caliper arms is rubbing right side. because they are similar) that we may come across? and also are the nipple's direction of rotation correct? thanks..

[xerxes]

Unless you're going to be building or truing a lot of wheels, I wouldn't worry about a truing stand, unless of course money is no object. You can true the wheel on the upturned bicycle, using the brake blocks as a guide and it's easier if you remove the tyre. I sit on a chair, with the wheel I'm working on, sort of between my knees. Then push the caliper over so that it brushes the rim on the side with "bulge" as it were. Working like this, your looking down on the rim from the inside of the wheel, so remember that turning the nipple anti-clockwise tightens and vice versa.

If you have disk brakes it's a little more awkward, but you could rig up something using a pencil taped or blu-tacked to the frame or fork.

When I true a wheel, I first check that all the spokes are evenly tensioned. If there are any lose ones, I tighten these to match the rest before actually doing any truing, I can sort out any additional wobbles this causes later.

When you look at a wheel, you'll see that the spokes go alternatively to the left and right side of the hub. Tightening those that go to the right side will pull the rim to the right and vice versa. However, you should always tighten and loosen spokes in sets, so if you have a bulge left exactly opposite a spoke going to the right, loosen the two spokes either side of the spoke going right 1/4 turn, then tighten the one going to the right 1/2 a turn. If the bulge is longer do them in pairs loosening and tightening as appropriate 1/4 turn along the length of the bulge.

I find up and down movement a bit more tricky to sort, but essentially you need to tighten the spokes going to both sides to pull in a bulge and loosen the spokes on both sides to let out a flat spot. If the bulge covers 4 spokes, tighten all by a 1/4 turn, then the middle two by another 1/4 turn and loosen them in a similar fashion to let out a flat spot.

Remember to pre-stress the spokes when your done, I do this by going around the wheel and squeezing parallel pairs together on either side of the wheel. Re-check for wobbles, make any adjustments and repeat until the wheel is good. It's quite tricky to get them absolutely perfect, I certainly can't, but I can live with a millimeter or so of movement.

Here are some more tutorials to take a look at:

http://bikeride.com/wheel-truing/

http://www.parktool.com/repair/readhowto.asp?id=81

http://www.bikemagic.com/maintenance/wheel-truing-basics/3041.html

[erdem]

(07-28-2010, 08:55 PM)xerxes Wrote:  However, you should always tighten and loosen spokes in sets, so if you have a bulge left exactly opposite a spoke going to the right, loosen the two spokes either side of the spoke going right 1/4 turn, then tighten the one going to the right 1/2 a turn. If the bulge is longer do them in pairs loosening and tightening as appropriate 1/4 turn along the length of the bulge.

for example in the first picture there is a bulge on the left exactly opposite of a right spoke. do you suggest loosening B and F nipples 1/4 turn than tightening D spoke 1/2 turn. that is quite interesting

(07-28-2010, 08:55 PM)xerxes Wrote:  I find up and down movement a bit more tricky to sort, but essentially you need to tighten the spokes going to both sides to pull in a bulge and loosen the spokes on both sides to let out a flat spot. If the bulge covers 4 spokes, tighten all by a 1/4 turn, then the middle two by another 1/4 turn and loosen them in a similar fashion to let out a flat spot.

i think here you mention radial truing.

thank you very much.

[xerxes]

Quote:for example in the first picture there is a bulge on the left exactly opposite of a right spoke. do you suggest loosening B and F nipples 1/4 turn than tightening D spoke 1/2 turn. that is quite interesting

Assuming that your diagram shows the inner surface of the rim, loosen C and E 1/4 turn and tighten D 1/2 a turn. If the bulge is only tiny, try loosening just 1/8 of a turn and tightening 1/4.

Think of the wheel rim a bit like the tip of a tent pole with two guy ropes coming from it. To mover the tip of the pole to the right, you need to loosen the guy rope on the left and tighten the one on the right and vice versa.

[erdem]

(07-29-2010, 09:13 PM)xerxes Wrote:  

Quote:for example in the first picture there is a bulge on the left exactly opposite of a right spoke. do you suggest loosening B and F nipples 1/4 turn than tightening D spoke 1/2 turn. that is quite interesting

Assuming that your diagram shows the inner surface of the rim, loosen C and E 1/4 turn and tighten D 1/2 a turn. If the bulge is only tiny, try loosening just 1/8 of a turn and tightening 1/4.

sorry, i think i didn't mention. the diagram shows the outer surface of the rim. we are looking from the outside of the rim. we assume there is a bulge on the left side between the dotted area. A, C, E nipples are on the left B, D, F nipples are on the right etc..

[xerxes]

Quote:sorry, i think i didn't mention. the diagram shows the outer surface of the rim. we are looking from the outside of the rim. we assume there is a bulge on the left side between the dotted area. A, C, E nipples are on the left B, D, F nipples are on the right etc..

Actually thinking about it, it doesn't make any difference which side of the rim we are looking at, you still need to loosen C and E 1/4 turn and tighten D 1/2 a turn.

[Joe_W]

Oh, and don't directly look into the rim when truing a wheel. Install the rim tape (well, unless you are building a wheel where you can access the nipples only from inside the rim).