Tension measurement for double butted spokes
11-11-07, 05:18 PM
#1
Senior Member
Thread Starter
Join Date: Sep 2006
Location: Spencer, IN
Posts: 689
Bikes: Trek 5200
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Tension measurement for double butted spokes
I just finished building up a wheel for a fixie, and I have a question concerning spoke tension.
I am sort of a parts bottom-feeder - for the build I used only stuff from my parts bin. I used an old 27" Araya single-wall rim, 32 used, double-butted 1.8/2.0 DT Swiss spokes, plus 4 used, no-name straight gauge 2.0 mm spokes. Now that the wheel is done I'd like to even out the spoke tension as much as possible, but those four straight gauge spokes are giving different tension measurements than the double butted spokes.
So - using the Park tension meter, should I consider the double-butted spokes as 2.0 mm gauge, or as 1.8 mm gauge?
And is it totally ridiculous to mix and match spokes like this?
Thanks!
I am sort of a parts bottom-feeder - for the build I used only stuff from my parts bin. I used an old 27" Araya single-wall rim, 32 used, double-butted 1.8/2.0 DT Swiss spokes, plus 4 used, no-name straight gauge 2.0 mm spokes. Now that the wheel is done I'd like to even out the spoke tension as much as possible, but those four straight gauge spokes are giving different tension measurements than the double butted spokes.
So - using the Park tension meter, should I consider the double-butted spokes as 2.0 mm gauge, or as 1.8 mm gauge?
And is it totally ridiculous to mix and match spokes like this?
Thanks!
11-11-07, 07:10 PM
#2
Senior Member
Join Date: Jul 2005
Posts: 7,487
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
Liked 162 Times
in
89 Posts
In using the tension meter, you place the gauge on the middle section of the spoke (i.e, the thinner gauge section of a double butted spoke), and then use the conversion chart. The spoke is considered to be whatever the thinner section of the spoke is (in your case, 1.8mm), so use the number on the chart that corresponds to the thinner gauge. It's all explained in the directions that come with the TM-1.
11-13-07, 09:07 AM
#3
Senior Member
Join Date: Jun 2003
Posts: 668
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
Liked 72 Times
in
48 Posts
The Park tool measures across the with of the spoke, so different diameter spokes at the same tension will give different readings. Equalize the tension in each spoke using the correct chart for each spoke.
em
em
11-13-07, 09:34 AM
#4
Geek Extraordinaire
Join Date: Feb 2006
Location: Long Beach, CA
Posts: 1,769
Bikes: Bianchi Advantage Fixed Conversion; Specialized Stumpjumper FS Hardtail
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I predict 4 broken spokes in your near future. The butted spokes are going to stretch more than the straight spokes as you ride, which will put a large load on the straight spokes.
__________________
I'd rather have a bottle in front of me than a frontal lobotomy.
Sintesi Conversion Serotta Track
I'd rather have a bottle in front of me than a frontal lobotomy.
Sintesi Conversion Serotta Track
11-13-07, 08:53 PM
#5
Senior Member
Join Date: May 2003
Posts: 253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I have a mix of butted and straight spokes in my rear wheel since May when I had three of the original butted spokes fail. So far so good. Personally, I think that if you have a tensiometer you can mix both without fear. In my case this was based on necessity because the LBS only had straight spokes available.
