Wheel building

[Tony T]

I taught myself how to build a set of wheels a few years ago. Used books suggested here (thanks!), and found the PROFESSIONAL GUIDE TO
WHEEL BUILDING by Roger Musson (and the help here) to be invaluable for my learning.
Wheels have kept true with only minor adjustments. I could not have done this without a tensiometer.

[MaraudingWalrus]

Like several others who have chimed in on this thread, I make a nonzero portion of my income from building bicycle wheels.

Tension meters are super helpful, bordering on essential.

Something like WheelFanatyk's digital plus various output cables and some programs that are out there allow very quick measurement of absolute spoke tension readings, and visually represent relative readings, like the extremely excellent one on SpokeService.ca. However the WF tool is absolutely overkill for an occasional home builder.

The Park tool is fine enough, the Wheelsmith one (developed by the WheelFanatyk guy years back) is good and can be found relatively cheap. You can send your old WS tool (or one found on eBay of unclear condition) to Ric at WF and he'll re-calibrate them. Hell, there are even some relatively cheap ones you can find on places like AliExpress or AliBaba that people have had great luck with.

As other Eric (Ergott) said, you really don't have a way of getting absolute tension of a spoke without one in any practical sense. Like yeah there's a formula that you could do a moderate amount of math from if you knew the pitch of a spoke plucked, but still.

It can be helpful to use tone to supplement usage of a tension meter along the way, I sometimes tap a spoke wrench on spokes or hold my fingernail or nipple inserting tool in a spot and spin the wheel to see if there are any spokes that are way out of tone relative to the others. But again, it's still relative, not absolute.

You don't actually win any points for doing something the old fashioned way or not using the specific tools made to do a job.

[David in Maine]

Thanks everyone for responding to my questions. I've learned a lot and enjoyed the discussion. So, as a first time spoke tensiometer user, how do I determine the correct tension for a particular build?

David

[MaraudingWalrus]

Originally Posted by David in Maine

how do I determine the correct tension for a particular build?

Generally, you'll build to the tension of the component with the lowest max tension spec. It's probably the rim. That information would be available from the rim supplier/manufacturer. It's probably somewhere in the 120kg/f range.

Here's a great WheelFanatyk post on the subject.

[oldpotatoe]

Originally Posted by MaraudingWalrus

Generally, you'll build to the tension of the component with the lowest max tension spec. It's probably the rim. That information would be available from the rim supplier/manufacturer. It's probably somewhere in the 120kg/f range.

Here's a great WheelFanatyk post on the subject.

Agree altho for most aluminum rims these days, 120kgf is the MAX..100-110 is a good range to shoot for.

[David in Maine]

Thanks Eric and Peter

Best,

David

[Tony T]

What I always found interesting is that once the tire is mounted, the tension drops (which makes sense as there is inward pressure on the rim)

https://www.wheelfanatyk.com/blog/te...arginal-gains/

Summary
Bicycle wheels lose a measurable amount of tension when a tire is mounted and inflated. Historically, this amount was insubstantial and no dedicated counter measures were needed. But today, owing to two recent trends, we have perfect storm that spells trouble and confusion.

Tubeless clincher tires requiring a tight bead fit to the rim.
Rim profiles ill equipped to manage the pressure of tight beads and inflation.
Outcome
Some rims shrink way too much with tight tires and can lose 50% or more of their tension and asymmetric ones (all rears and disk fronts) become uncentered in the frame.“Tension drop” is worrisome and there is little consensus about what to do once a bad rim design is in the workshop.

[ergott]

It's a real issue and one that many industry leaders have been getting together about. Hopefully they get it right. A variance of a couple tenths of a mm is enough to make tension loss significant and it occurs frequently.

[marciero]

Not to beat this to death, but I showed above that most people can detect 1% difference in tension by pitch and guessed that would be on par with tensiometers in detecting evenness of tension. I was assuming +/- 1% for tensiometers. Poking around the site linked above it turns out that due to inconsistencies in spoke extrusions, tensionmeters can be much, much less accurate than that. If you get Jobst's design it is supposedly better because it does not depend on spoke thickness. But I dont see how it does not depend on production consistency; eg, the wall thickness, and so would be sensitive to manufacturing tolerances. Would think it frustrating on top of dealing with charts, calibration, re-calibration, etc.

https://www.wheelfanatyk.com/blog/tension-inaccuracy/

[David in Maine]

Because of this tendency, should one do final dishing and tensioning with tires mounted and inflated?

David

[redir]

ONe would have thought they would have built the reduction in tension into the spec...

[marciero]

...of course, just because a tensiometer is 10% off (or 20%, or 50%...) - and this is on top of the +/- variability- does not mean it will not be consistent. But I thought the whole point here was correct absolute tension.

[Mark McM]

Originally Posted by redir

ONe would have thought they would have built the reduction in tension into the spec...

What makes you think the manufacturer's tension spec. is more than a guess?