George

I got the Open Pro wheels about a month ago and decided to check them out. They where pretty true, but the back wheel lost some of ti's tension. I brought it up to the readings that were on the wheel when I got it which were 22 kgf on the drive side and 15kgf on the NDS. Anyhow after truing and playing with them for a few hours I said the heck with it. When I stress relieve them, I always get the pinging and popping and I have a few spokes off again. Then I start all over again and again and again. The feelers on the truing stand are about a half mm off the rim and once in a while the rim just barely touches the rim in one spot or another. I was wondering, what's acceptable.

capwater

.5mm with uniform tension would be fine.

Joshua A.C. New

The pinging can be greatly reduced by lubing the nipples. Since the wheel's already together, you probably want a penetrating oil or Tri-Flow so it works its way between nipple and rim. Most pinging, in my limited (four wheels) experience is from twisted spokes. Letting the nipples turn freely will let the spokes untwist without unscrewing.

kycycler

A little Phil Wood Tenacious oil on the nipples works wonders

SweetLou

As stated above, the pinging and popping is from spoke wind up. When you tension spokes, they slightly twist, you need to remove this wind up, otherwise they will untiwist themselves while riding, throwing the tension off. Straight gauge spokes are not as bad as swagged spokes, bladed spokes are the worse.

When you tension the spoke, you should go farther than you want, then back off a bit. For example, you want to turn the nipple 1/4 of a turn, then turn the nipple 1/2 of a turn, then go back 1/4 of a turn. If you put a finger from the non wrench hand on the spoke, you can feel the wind up. With some practice, you will be able to know exactly how far past you need to go then back so there is no twist in the spoke.

Lubrication is very helpful. I soak my nipples in oil prior to lacing a wheel. If the rim doesn't have eyelets, I also like to put grease on the outside of the nipple head, where the nipple touches the rim.

rm -rf

Spokes have less tension after the tire is mounted and pumped up. So don't compare the tension readings from the truing stand to the readings when the tire is inflated. I assume it's because the 110 psi is slightly compressing the rim.

George

Thanks for the replies guys. You know, I thought about lubing them, but when I got going I forgot all about it.

SweetLou

This should only be for tubular tires. Tubular tires will push on the rim, causing the spoke tension to be lower. But on clinchers, the tube pushes on the rim bed and the bead pulls up on the hooked rim edge. These forces will be equal, causing no net downward force.

Al1943

I don't believe the values given are kgf, 15 and 22 would not keep the wheel held together. If you are using a Park TM1 then those numbers would be reasonable for Park deflection numbers that can be converted to kgf with the Park chart.
There is a significant difference in spoke tension values on my clincher wheels when comparing inflated tubes and tires with values from a bare rim. I due a final truing after the tires are fully inflated.

Al

Sixty Fiver

The last wheels I built were trued to a tolerance of < 1/1000 inch or about <.25 mm (if my conversion is correct) but these were some pretty exemplary wheels that were built for a friend of mine who tips the curb at about 240 pounds.

My friend has been hammering these wheels hard for over a month and on checking them they are still
< 1/1000 and the guys at the LBS (who are some great wheel builders) are really impressed.

Today is my first day as a non amateur mechanic btw...

operator

Wrong.

This happens frequently on low quality clincher wheelsets.

15 and 22kgf? Are you serious? That's like 0 tension.

DDYTDY

.25mm X .03937 = 0.0098"

.001" = .025mm

Congrats on the new gig!

George

I'm probably reading this thing wrong, but it's time to hang it up and take it to the LBS. The readings on the card are 15 being 82kgf and 22 are 157 kgf. They are DB spokes 2.0-1.5-2.0. Every time I stress relieve the spokes they throw the wheel all out of true again. I've been playing with this d*** thing for 5 hours. Man I'm so aggravated, I'm feel like throwing all this stuff away. Thanks for the help guys, I'm going to bed

SweetLou

Really? As the tube expands, it pushes down on the rim with the same force as it pushes up on the tire. Since the tire is connected with the rim at the hooked edge, the tire is pulling on the rim with the same force as the tube is pushing down.

Go measure the spoke tension on an inflated tire, then let the air out and measure it. It will remain the same, unless it is a tubular. I just did this experiment to be certain and the spoke tensions remained at the same tension.

SweetLou

Don't get aggravated and don't give up. Wheel building needs patience. If I were you, I would start over, loosen everything up, don't unlace the wheel. I like to start with the threads not showing out of the nipples, but just barely all the way in. You could start with one or two threads showing. Pick a spot, I always pick the valve hole and go around the wheel turning each nipple one turn.

If the spokes are still pretty loose, do it again with 1 complete turn. Remember to do the entire wheel, all the way around to the valve hole again. Once tension starts to appear in the spokes lower this to a half a turn of the nipple. Then 1/4 turns.

Once you get the wheel close to final tension, start centering, truing and rounding the wheel. If you have a good rim, there shouldn't be much truing needed. Since this is a rear wheel, it might not be centered as well as it should be. If this is the case, go around the wheel again with 1/4 turns but only on the side that needs to be tighten to pull the wheel to center. You might need to loosen the other side if there is too much tension already.

Once you get the wheel tensioned ture and centered, if you stress relieve and the wheel comes out of true and you have two big waves in the rim, then it was over tensioned. You need to back off a bit.

Sixty Fiver

Thanks... there's something about being paid for doing something you'd be happy to do for free.

Wordbiker

I know, but gigolo clients are tough to find.

Sixty Fiver

I am in much demand in these parts... Monday nights see a lot of really vintage bikes since I am the "old bike" guy and there have been a few people surprised to find I can also work on and do ride modern geared bikes.

They aren't nearly as fun as the old girls and I just realized I have a bike from every decade going back to the early 30's.

What 20's model should I be looking for ?

Wordbiker

Any model in her 20's is likely to be a lively ride

markjenn

We've been over this before on this forum and while I can't argue with your data, it has been VERY WIDELY reported that spoke tension goes down slightly (5% or so) after tire inflation on all types of rims/tires. Do a search.

I don't think your "hooked bead pulls as hard as tube pushes" explanation makes much sense. I doubt the bead hook is under much tension after inflation.

- Mark

dabac

Unless you're using black spokes a helpful trick is to run a magic maker pen down the spoke. That'll give you a line to use as an indicator for spoke wind-up. Count the nipple twist WRT the line instead of WRT the rim.
After final trueing a dash of pretty much the solvent of your choice on a rag will be sufficient to wipe the line off.

A slightly more labor-intensive method that works on black spokes is to cut small strips of tape and fold them double over the spoke, like small flags. They'll do a good job of indicating wind-up too.

SweetLou

I couldn't find any threads on the tire inflation, if you know of any, I would like to read them. Though, I found the problem, I didn't take into account the cord angles in tires. The forces of the tube pushing on the rim and the tire pulling on the rim are equal and cancel each other. But because the cords in tires are at angles, inflation will cause a net inward pressure. Depending on the tire, you will get different results.

George

Well it's morning and I'm going to try and get this thing again. I did lube all the nipples before I started last night, but they kept losing it. I'll see what happens today. Oh and by the way, I did check the tension out, with air and without and their wasn't any difference at all.

Al1943

Try holding the spokes with pliers to avoid windup. Soft jaw pliers are available if you're concerned about scoring the spokes.

Al1943

This is about what I've experienced on clinchers, and 5% is pretty significant.