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-   -   Does Anyone Know How to Build/True Campy Wheels? (https://www.bikeforums.net/bicycle-mechanics/1230059-does-anyone-know-how-build-true-campy-wheels.html)

tNuvolari 05-08-21 08:21 PM

Does Anyone Know How to Build/True Campy Wheels?
 
So I have a set of Campy Proton wheels and I'm basically trying to learn how to true the rear wheel and, yeah, it's going about as well and you'd expect....I've read a bunch of stuff but nothing ever seems to work in real life compared to what I've read.

So, the basics here:

Campy Proton rear wheel. Asymmetric and a pain in the ass. Drive side spokes are 1.8 round and non drive are 1.5. I've read that the proper spoke tension of the drive side is 130-150 kgf which seems high but that's what I've found. Not a G3 lacing but radial on the non drive side and cross 2 on the drive side.

Anyway, the main problem I'm having is with the dish. No matter what I do, I can't really get it to change. I've completely loosened the spokes and started from scratch but the dish never changes even when cranking the tension from one side to the other. I assume this wheel, although "asymmetric," is still centered with regard to the dish and hub.

I can't even tell which side should be tighter to move the dish one way as it barely moves no matter what and obviously it's a good deal uncentered.

Any ideas or help appreciated.


https://cimg1.ibsrv.net/gimg/bikefor...68c581d2e9.jpg
https://cimg4.ibsrv.net/gimg/bikefor...6f3b9a75e8.jpg
https://cimg5.ibsrv.net/gimg/bikefor...5f0abc6f8c.jpg

oldbobcat 05-08-21 09:28 PM

Are you saying that no matter how hard you tighten the spokes on one side and loosen the spokes on the other, the dish remains untouched?

tNuvolari 05-08-21 10:06 PM


Originally Posted by oldbobcat (Post 22051130)
Are you saying that no matter how hard you tighten the spokes on one side and loosen the spokes on the other, the dish remains untouched?

Well, within reason. I mean I haven't gone crazy with tightening as I'm trying to stay within the appropriate spoke tension. But whether the spokes are basically untensioned compared to one side at 75% compared to both sides at about 90% compared to one side at 100% to the other side at 100%, there is barely any difference. And I can't even tell which side to tighten to move the hub one way. From what I've observed, it seems you tighten the opposite side from the direction you want the hub to move but I'm not even sure of that because the movement is barely noticeable.

It is now around 8-10mm difference from one side to the other as far as the dish which is fairly extreme, I would think. I assume it should ideally be close to 0 or maybe 2-3mm max.

oldbobcat 05-08-21 10:18 PM


Originally Posted by tNuvolari (Post 22051164)
Well, within reason. I mean I haven't gone crazy with tightening as I'm trying to stay within the appropriate spoke tension. But whether the spokes are basically untensioned compared to one side at 75% compared to both sides at about 90% compared to one side at 100% to the other side at 100%, there is barely any difference. And I can't even tell which side to tighten to move the hub one way. From what I've observed, it seems you tighten the opposite side from the direction you want the hub to move but I'm not even sure of that because the movement is barely noticeable.

It is now around 8-10mm difference from one side to the other as far as the dish which is fairly extreme, I would think. I assume it should ideally be close to 0 or maybe 2-3mm max.

Then methinks you should practice on something a more prosaic than a Campagnolo Proton. The brand of wheel doesn't change the principle, but exotics are definitely more difficult to work on.

Are you even using a truing stand or a dishing tool?

dabac 05-09-21 03:12 AM


Originally Posted by tNuvolari (Post 22051164)
And I can't even tell which side to tighten to move the hub one way. From what I've observed, it seems you tighten the opposite side from the direction you want the hub to move but I'm not even sure of that because the movement is barely noticeable.

The way I work it is that I consider the hub stationary, and I move the rim.
The side I want the rim to move to is the side that I tension.
While I find your reference frame awkward, it seems like it amounts to the same thing.
If you want the hub to go to the left, you tighten the right side spokes.

easyupbug 05-09-21 08:01 AM


Originally Posted by tNuvolari (Post 22051074)
No matter what I do, I can't really get it to change. I've completely loosened the spokes and started from scratch but the dish never changes even when cranking the tension from one side to the other.

I don't understand how this can not be true. The required dish is what determines the difference in spoke tension. I have the same factory protons and spokes, they are true, w/ 1,000s of miles on them and checked my log, DS 120 to 135 and NDS 80 to 88.

70sSanO 05-09-21 08:33 AM


Originally Posted by dabac (Post 22051266)
The way I work it is that I consider the hub stationary, and I move the rim.
The side I want the rim to move to is the side that I tension.
While I find your reference frame awkward, it seems like it amounts to the same thing.
If you want the hub to go to the left, you tighten the right side spokes.

Over the past year I have been swapping out a few freehub bodies, 9 to 7, 7 to 8, that results in having to re-center the rim. To make sure I don’t lose my concentration and get confused mid-circumference, I start at the valve hole and set the rim in the stand so I can do righty-tightly/lefty-loosen. It doesn’t matter the orientation in the bike, it just matters which direction I need to move the rim to get the dish. Since I’m going around the rim multiple times I just repeat the righty/lefty.

I’ll flip-flop the rim in the stand when I’m doing the final lateral truing, but by that time the dishing is done.

John

Crankycrank 05-09-21 08:35 AM

Second photo sure looks like the middle spoke is pulling the eyelet through the rim. Could be an optical illusion but if so that rim is pretty much done for.

3alarmer 05-09-21 08:44 AM

.
...I don't know how that hub is constructed, but on a standard wheel, when the dish is off and off by a lot, sometimes it's easier to go at the axle and swap out the various spacers to move the rim over in the dropouts. In your case, without the wheel in front of me, I haven't a clue if this will work for you.

alcjphil 05-09-21 09:46 AM


Originally Posted by oldbobcat (Post 22051173)
Then methinks you should practice on something a more prosaic than a Campagnolo Proton. The brand of wheel doesn't change the principle, but exotics are definitely more difficult to work on.

Are you even using a truing stand or a dishing tool?

There is nothing exotic about Campagnolo Proton wheels. They use ordinary J-bend spokes

dananton485 05-09-21 10:20 AM

It is possible that you have the spokes attached to the rim on the wrong side that is usually most hole are slightly offset to on side on the rim if by chance your pulling the left holes on the right side or vice versa that may be your issue. The dish can be done towards the end. Get the rim semi true then pull the drive side over. I usually do a full turn on all drive side spokes then check it. Don do tension till the end

easyupbug 05-09-21 11:13 AM

Here is my factory stock Proton DS, except for the Pitlocks, they true as easy as any wheel I have ever put in a truing stand. Spokes came in black on some years, straight pull spokes DS only, NDS and front are conventional J bend. OPs spokes can not be switched DS to NDS. I am liking Crankycrank's comment, I don't like that second photo nipple washer looking like it is pulling through, wonder if these were abused some way?
https://cimg8.ibsrv.net/gimg/bikefor...78626f1af.jpeg

oldbobcat 05-09-21 12:47 PM

Any wheel that uses fewer than 28 spokes is exotic. Any wheel that uses bladed spokes is exotic. Any wheel that uses straight-pull spokes is exotic.

Here's my beta for dishing wheels.
  1. Loosen all the spokes on the tight side, that is, the side you want to pull the rim away from. Start and finish at the valve hole. Loosen by a consistent amount, like one full turn.
  2. Tighten all the spokes on the loose side (opposite of the tight side). Tighten by a consistent amount, like 1/2 turn. You don't want to fully tension the wheel yet.
  3. Do a "rough" truing. That means true out hops, flats, and large lateral deviations, as you tension the wheel.
  4. Detension wheel.
  5. Check the dish and trueness.
  6. Repeat as necessary.
  7. Do a final truing and tensioning.
Things to remember about exotic wheels. Low spoke count means be careful. Work gradually. Don't pull or release too much tension at once. Straight pull spokes might twist where they're anchored in the hub. Find a way to hold them. Bladed spokes tend to twist longitudinally as you twist the nipple. Use a tool to grip the spoke.

And yes, by the way that rim is distorted at the nipple hole in the second photo, I'd say it is toast.

davidad 05-10-21 12:09 PM

Once I have built up a wheel and brought it to proper tension I use the NDS spokes on the rear to center the rim. Lower spoke count wheels require a lot more tension to make up for the fewer spokes to carry the load.


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