BNB

For those of you who build wheels: I built a new front wheel for my single road bike: hed belgium c2 rim, cx ray spokes, bike hub store hub. the challenge for me was the bladed spokes and finding the correct reading for the park tool TM-1 tensiometer. the rim is rated for 100kgf. I measured the thickness and width of each spoke (individual spokes vary quite a bit giving a large range for TM-1 tensiometer) and took and average and came up with a reading of 13 on the TM-1 using their online app. Is it necessary to reach the maximum spoke tension? I used the park tool app to calculate my average spoke tension (83 left / 78 right). Should I go higher? I'm on the lighter side at 115 pounds.

I'm using wheelsmith spoke prep which is new to me (I used linseed oil on the first build). Not sure how long I can wait to tweek this wheel further though I realize people true their wheels having used spoke prep so I'm guessing it can wait another day. ??

I've attached a pic of the output from the wheel tension app which is kinda cool, I think, and the wheel 'cause I like blue hubs!

Bill Kapaun

Just glancing at your chart, it appears the blue "dot" at 6 o'clock could have a bit more tension at the expense of the 2 adjacent blue "dots'. Ditto with the one at 8 o'clock, which would BOTH help reduce the high reading at 7 o'clock.

Kind of a "ditto" with the one at 12 o'clock.

Just go slow.

It's my understanding that bladed spokes are made of round stock that is "flattened".
IF SO, the cross sectional area (for that batch of spokes) will be the same, no matter what shape it's in.
Of course, measuring will suck.

When I first started building wheels, I got a bunch of small alligator clips at RS. Red, Black and a smaller amount of Yellow & Green.
I took a rough average of my tensions and assigned an "average" for that side of the wheel.
I'd then add 1 Red clip per "number" on the TM-1 for over and a Black for 1 under.
I would assign arbitrary values for the Yellow & Green for values such as 2 over/under etc. if I was running out of Red/Black clips.

It was SO MUCH faster than writing down the numbers and then entering it into the computer.
It also gave a better "visual", because you could look at either side by just moving the wheel in your hands.
It made the corrections needed MUCH more obvious.
I still use that method on used wheels that are way out of whack.

FBinNY 

Two points.

1- there is absolutely no need or reason to go to the maximum tension, especially on a front wheel. It's like with bridges, if it's rated for 8 tons, do you feel it's safer to park a 6 tin truck on it before crossing in your car?

The max tension relates to what the rim can take before distorting, or risking nipples coming through. Of course it factors the added load when in use. The minimum tension is what's needed to get the spokes into a working tension range, and depends on the payload, and spoke number and gauges. For a front wheel that's considerably less than 100kgf, so I'd roughly estimate that with butted spokes anything above 50kgf is plenty.

My second point is about converting tension meter readings to kgf. For this, the thickness of the spoke (in the direction you're measuring) is what matters.

The two reasons are

1- the meter deflects the spoke and since they have stiffness relative to their thickness, that needs to be known.

2- the meter reads the spoke with 2 contacts on one side and the middle contact on the other, then measures how far the middle can push the spoke into a bow. So the zero point (straight, undeflected spoke) will be when the line between the contacts is the thickness of a spoke. That's a bigger factor than the one above, and why every tension meter has to produce conversion charts for each gauge (where measuring, not the ends).

If you don't have a chart for your spoke's thickness, you can measure and interpolate the values using those on either side as references.

Jiggle

It's a good looking wheel. That is a laterally stiff rim so you don't need much tension as FB noted. But you'll lose some tension with tire install and you want a little safety factor. I'd go 75, which is what you have.

FBinNY 

For the record, I don't obsess over tension the way many here do. I started building wheels long before tension gauges were common, and let the wheel tell me when I'm on target.

These days, even though I own a tension gauge, I still don't try to pre-decide on a specific tension. I know where I am because of how the spokes and rim respond to adjustments. If building with unfamiliar materials, I'll use a tension gauge for a "reality check" to see if the practical and theory jibe. This is more important to me for heavy riders or thicker or fewer spokes where the proper tension range is narrower, especially on rears where dish has the right side pushing the tight limit, while the left is barely at minimum (at the same time).

But, as I said earlier, a front wheel with a stout rim is very forgiving, so it's hard to go far wrone.

BNB

Good reality checks - thanks so much! I like the idea of marking spokes with colors (don't know what RS is??) which would make it much more obvious about balancing. I like the online park tool app as it also made it more obvious about balancing, but more work as FB suggests. As a newbie who obsesses on about the perfectly true wheel I sorta dread tightening and/or loosening spokes to get better balance. I walked away when I got tired, grabbed a beer and wait for tomorrow. Still so much more fun than buying off-the-shelf wheels. Plus, this wheel set will cost me $428 and be pretty darned light. And pretty.

FWIW, I bow to those with lots of wheel building experience. This will be my second set of wheels and I use every tool available to me. I don't want to experience catastrophic failure to learn what doesn't work.

Thanks for your help.

Bill Kapaun

RS = Radio Shack

FBinNY 

Is Radio Shack still with us?

Bill Kapaun

They still have a website.
Ours closed about 2? years ago.