wheel building: spoke tension
I'm building my first set of wheels. I started with the front. The lateral and radial true is pretty good, but I can't seem to get it just right--it's like I hit a plateau and each round of truing puts more tension in, and I worry I've over tensioned. So I decided to bring it to the local shop to get an opinion. I don't have a tensiometer and I also don't have a comparable wheel to compare to. It's a mavic open sport rim, wheelsmith straight guage 2.0mm spokes, and a tiagra hub.
the guy at the shop said that they used a DT swiss tensiometer and therefore they couldn't give me an accurate reading on wheelsmith spokes. he didn't seem to have an opinion about whether it had too much tension or not, but he did take a reading with the tensiometer because I asked if he would. It read around "2.5" or "2.4" for the few spokes he measured. Using the little booklet he had for a DT swiss champion 2.0mm spoke this translated into 1400n. My understanding is that a good wheel should have between 90-130 kgf of tension...but I'm just basing this off a few different things I've read online. as I said, I'm a novice.
if the reading from his DT tensiometer is anywhere in the ballpark that means I've got around 140 kgf in the spokes, which seems high. I get the feeling just from squeezing it that it is on the high side. a) is the measurement accurate given that I've got wheelsmith spokes? and b) what should I do? I worry that I've damaged the nipples because a few of them look a little oval where the spoke protrudes. thanks for advice!
Assuming that the conversions are correct, I would back off the tension a very small amount. But it sounds as if there is a lot of room for error in the conversion.
A Park TM 1 is only about $60. I assume that the conversion chart for it is not highly accurate.
I guess what I'm asking (in my very long post) is how to translate the reading from the DT swiss tensiometer into a meaningful value for my wheelsmith 14 gauge spoke. I'm just curious to know how much tension my spokes currently have.
Might not be good enough for laboratory research, but just use the values for a DT 14 gauge spoke and you'll be plenty close enough for wheelbuilding purposes.
Originally Posted by dasding
that's what I figured. its pretty clear I put too much tension in. loosened all the spokes and I'm starting again from there.
Originally Posted by Retro Grouch