Soyjim

I have a 28 paired spoke wheel on the back of my new bike. I don't know a lot about these paired spoke wheels, or any wheel. Now that I have one with a problem it seems to me there is not a whole lot of availabe information. I didn't think that they were a bad design in the late 90's the Trek lbs that I lived near recommended Bontrager paired spoke wheels for a cross country rider that they helped sponser. The rider felt good about the wheel. He had one spoke break on the cross country ride.
My current problem is that twice I have had the same spoke work loose. I took it to the small bike shop near me to have them look at it. I don't think he was real familiar with paired spoke wheels. He set the drive side wheels with a tension meter to he said 20 and the nds was less. After some research I assume this is 120 kilograms force. I feel like the spoke tension is still pretty springy especially for what my research has led me to believe is supposed to be a high tension wheel. I called a bike shop quite aways from me that carries Jango bikes and they measured the tension at 135 on rear of both sides of the bikes they have on the floor. I haven't found much on line or in the material that came with the bike about paired spoke tension.
I ask any of you that have some experience with paired spoke what the tension should be, and should the tension be pretty much the same on both sides of the rear wheel? The lbs said my spokes were standard spokes which I think means round 20 guage spokes.
I think my rims must be really sturdy cause at least twice I must have ridden the bike with one spoke so loose I could tighten a nipple with my fingers. I sent an email to todson, Topeak's US representative. They said they needed to research it and would get back with me next week, if I still wanted the information. Hopefully they will get back to me.
I have found a Bontrager web site on there wheels that leads me to believe that a wheel they sell with 20 guage spoke is supposed to have a tension of 130 to 170. Not sure I am fully understood info presented in that site though. Have not found any info about tension in rolf wheels other than they are high tension wheels.

mrrabbit 

1. Assumes alloy wheel...

2. Read according to what the tension meter indicator TRANSLATES to on the accompanying chart for a given guage spoke.

3. Get the front spokes up into the 100-110 kgf range...

4. Get the rear drive side up into and even a little past 110 kgf.

5. For carbon stuff...you really need to check the OEM technical bulletins / papers / specs.

=8-)

dabac

That's a bit odd. Not impossible - but odd. For an average current rear wheel w/ external gears the DS tension run higher, but not doubly so. Switching to a paired configuration w/o messing about with the flange placement should have the NDS tension running higher.

Really no way of telling, w/o knowing what tensiometer he's using and the spoke gauge. For a Park 20 = 120 only if you run a 1.6 mm spoke.

Don't really know what you mean by that, but high tension is not a guarantee for a rigid wheel.

Which would be a fairly reasonable for a paired spoke, low-count wheel.

There's not that much to it. Standard practise wheel building is to take the DS to whatever the rim manufacturer or experience tells you is OK, then use whatever it takes on the NDS to get the wheel centered on the axle. Main difference is that with a paired build you can have NDS tension closer or even surpassing NDS tension. There might even be a point where you'd set NDS tension first, and then bring the DS up whatever it needs.

That would be the goal, yes. Exactly how close to even it's possible to get would depend on hub flange placement.

A reasonable assumption.

At 28 spokes, losing one isn't too bad - particularly if it's one out of a pair.

That shouldn't be. Is it a radial spoke? They are said to be more prone to unwinding. I was going to suggest spoke wind-up during build, but that shouldn't be an issue for a straight gauge spoke.

Would depend on the spoke count. I've been looking at two 20 spoke rear wheels recently. One has a recommended tension of 130-150 kg, the other 140-160 kg. A pretty good match to your 130-170.

Soyjim

Thanks for your replies. not sure what I should do. My first inclination is that I should have the shop set both sides to about 135. I think I saw that it is bad for a wheel to have a spoke work loose. I really need to see if what the lbs did fixed the problem. I think I will go for a 10mile ride which is when I noticed the problem. It will be a while before I can find the time to experiment. Don't want to get caught far from home though. In the mean time maybe someone here will suggest a better course of action. luckily the weather is only fare now. todson might also respond with an answer. I will post here if they do. I think I will talk to lbs and see what they suggest.

AEO

that's for normal wheels.
paired spokes require higher than normal tension. but how high, I have no idea.

joejack951

The main thing the shop needs to do is to set the tension evenly amongst all of the spokes on one side. If they cannot get tension within ~15% from one spoke to the next (on the same side), take the wheel to someone else (unless the rim is damaged in some way to cause the difficulty in balancing tension). The tension balance from left to right will be determined by the geometry of the hub and rim. You cannot simply set the tension equal and get a properly dished wheel, at least not for a highly dished wheel like a modern rear wheel. As dabac pointed out, the tension should be set on the drive side to the maximum recommend tension recommended for the rim and then the non-drive side should be tensioned until the wheel is properly dished. For a paired spoke wheel using half the number of drive side spokes of a normal wheel, you may end up doing the reverse though as non-drive side might be higher than drive side.

micah356

I recently acquired a 2007 LeMond Reno, with the Bontrager SSR wheels. The wheels are very flexible, and rub the brake pads when I pedal or corner hard. Pushing on the wheels with my hand I can see that they bend to the side really easily. I just checked the tension, and the tightest spokes are around 120-125 Kgf. I was under the impression that paired-spoke wheels needed higher tension, correct?

mrrabbit 

Paired spoke wheels need higher tension - if the manu recommends it. It's not by default...however most are. Most Bontrager fronts will be in the high teens to 120+ range and the rears in the 130-140 kgf range. Park Tool website has a good chart for recommended tensions on various branded wheels - quite a few Bontrager's listed.

Visit the Park Tool website...

=8-)

joejack951

Check your wheel bearings.

Soyjim

wheel update. topeak-todson responded with the following quote.

"The spoke tension on Jango 7.0 rear wheel is 74~114kgf for both drive side and non drive side."

I am not sure what the bike shop did because it did not work. They said they set the drive side upto about 20. The nds was set at less. When I checked the wheel I thought their was some give in the spoke tension at some points where the spokes crossed and touched. I rode the bike a little and the spokes loosened up right away. I went around and tighted all the spokes to where I thought all the tension play was gone and tried to get the tension as even as I could by feel and sound. After that I have been on several 10 to 20 mile rides and the spokes have remained tight. Hope I have it fixed.