Suggestions.......Wheel Building....

[weisan]

And now, we wait.

[oldpotatoe]

Originally Posted by weisan

How can you tell one rim is of higher quality than the other?

What are the indicators?

You can a lot about a rim when you build it. When it seems all you are doing is centering the hub, build goes really fast with really even tension, great rim. When it seems to fight you, takes forever and any sort of stress, trying to take spoke windup out and it goes to hell....plus ya futz with it and the tension is all over the map, probably soft or poorly made rim.

But remember, ride=stays true, is the test.

[weisan]

Thank you Old pal, I guess I have been pampered so far, using mostly high-quality rims and the build went relatively easy without any hitch.

Velocity A23
H Plus Son Archetype
Pacenti SL23
HED C2 Belgium

Yep...all passed the test so far.

[Black Dog]

Originally Posted by weisan

Thank you Old pal, I guess I have been pampered so far, using mostly high-quality rims and the build went relatively easy without any hitch.

Velocity A23
H Plus Son Archetype
Pacenti SL23
HED C2 Belgium

Yep...all passed the test so far.

Those are all rims that build up well. Add DT to that list and it will be complete.

[oldpotatoe]

Originally Posted by weisan

Thank you Old pal, I guess I have been pampered so far, using mostly high-quality rims and the build went relatively easy without any hitch.

Velocity A23
H Plus Son Archetype
Pacenti SL23
HED C2 Belgium

Yep...all passed the test so far.

Ya need to go toe to toe with a Sun or Fiamme rim..maybe a used one..if ya can make that true/round/dished/tensioned..and it stays that way, you can build anything. As has been mentioned, DT..really excellent rims.

[OperaLover]

Just laced up a set of Campy Victory Strada tubulars to Miche Race hubs, 11-speed, 36 H, using DT Comp DB spokes, 3X, alloy nips in the front and brass in the rear.

Is there an ideal ternsion I should be going for? I've built and tensioned wheels before, but always went by feel, or plucking. I just got a Park TM-1 so I want to do these right. Any suggestions?

Thank you!

[oldpotatoe]

Originally Posted by OperaLover

Just laced up a set of Campy Victory Strada tubulars to Miche Race hubs, 11-speed, 36 H, using DT Comp DB spokes, 3X, alloy nips in the front and brass in the rear.

Is there an ideal tension I should be going for? I've built and tensioned wheels before, but always went by feel, or plucking. I just got a Park TM-1 so I want to do these right. Any suggestions?

Thank you!

100 kgf..right side rear and front.

[OperaLover]

Thank you, OP! I'll post photos when I am done. I'm having alot of fun building these wheels.

[weisan]

Originally Posted by oldpotatoe

Ya need to go toe to toe with a Sun or Fiamme rim..maybe a used one..if ya can make that true/round/dished/tensioned..and it stays that way, you can build anything. As has been mentioned, DT..really excellent rims.

I have done a few of those, certainly make me appreciate the ones that come straight and round without much adjustment.

[Mark McM]

Originally Posted by OperaLover

Just laced up a set of Campy Victory Strada tubulars to Miche Race hubs, 11-speed, 36 H, using DT Comp DB spokes, 3X, alloy nips in the front and brass in the rear.

Is there an ideal ternsion I should be going for? I've built and tensioned wheels before, but always went by feel, or plucking. I just got a Park TM-1 so I want to do these right. Any suggestions?

Thank you!

Originally Posted by OperaLover

Just laced up a set of Campy Victory Strada tubulars to Miche Race hubs, 11-speed, 36 H, using DT Comp DB spokes, 3X, alloy nips in the front and brass in the rear.

Is there an ideal ternsion I should be going for? I've built and tensioned wheels before, but always went by feel, or plucking. I just got a Park TM-1 so I want to do these right. Any suggestions?

Thank you!

There are multiple variables that determine the optimum spoke tension - there's no single tension value that will work with all wheels. For wheels with heary rims and a low number of spokes, the tension limit can sometimes be the strength of the rim's spoke bed, or more often, and especially if thing spokes are used, it is the torsional strength of the spokes (the spokes can only bear so much twisting force). For wheels with lightweight rims and a large number of spokes, the tension limit will be the circumferential compression strength of the rim.

The spokes all pull radial inward on the rim, basically trying to shrink the diameter of the rim. When the forces from all the spokes are combined, there can be a very large circumferntial compression load on the rim (often more than 1000 lb.) If the spoke tensions are too high, it can cause the rim to be prone to buckling (when a rim buckles, it can assume the classic "potato chip" shape). The lighter and shallower the rim, the less circumferential compression force it can bear.

I have found that a good limit for spoke tension for aluminum rims with 28 or more spokes to be:

T = C x W / N

where:

T = spoke tension in Kgf

W = weight of the rim in grams

N = number of spokes

C = Rim strength constant, which for aluminum rims typically has a value in the range of 8 to 9 Kgf-spokes/gram.

From Velobase, the weight of Campagnolo Victory Strada rims is 370 grams. Using a a value of 8.5 for C, the recommended average tension would be:

T = (8.5 kgf-spokes/gram) x (370 grams) / (36 spokes) = 87 kgf

For rear wheels, the recommended tension will be the average of the (high tension) right and (low tension) left spokes, so depending on flange offsets, you might end up with tensions something like 105 kgf right/ 65 kgf left, which isn't much different from Peter's recommendation. But 100 kgf average tension will be too high for the front wheel, and a value closer to 87 kgf would be recommended.

[oldpotatoe]

Originally Posted by Mark McM

There are multiple variables that determine the optimum spoke tension - there's no single tension value that will work with all wheels. For wheels with heary rims and a low number of spokes, the tension limit can sometimes be the strength of the rim's spoke bed, or more often, and especially if thing spokes are used, it is the torsional strength of the spokes (the spokes can only bear so much twisting force). For wheels with lightweight rims and a large number of spokes, the tension limit will be the circumferential compression strength of the rim.

The spokes all pull radial inward on the rim, basically trying to shrink the diameter of the rim. When the forces from all the spokes are combined, there can be a very large circumferntial compression load on the rim (often more than 1000 lb.) If the spoke tensions are too high, it can cause the rim to be prone to buckling (when a rim buckles, it can assume the classic "potato chip" shape). The lighter and shallower the rim, the less circumferential compression force it can bear.

I have found that a good limit for spoke tension for aluminum rims with 28 or more spokes to be:

T = C x W / N

where:

T = spoke tension in Kgf

W = weight of the rim in grams

N = number of spokes

C = Rim strength constant, which for aluminum rims typically has a value in the range of 8 to 9 Kgf-spokes/gram.

From Velobase, the weight of Campagnolo Victory Strada rims is 370 grams. Using a a value of 8.5 for C, the recommended average tension would be:

T = (8.5 kgf-spokes/gram) x (370 grams) / (36 spokes) = 87 kgf

For rear wheels, the recommended tension will be the average of the (high tension) right and (low tension) left spokes, so depending on flange offsets, you might end up with tensions something like 105 kgf right/ 65 kgf left, which isn't much different from Peter's recommendation. But 100 kgf average tension will be too high for the front wheel, and a value closer to 87 kgf would be recommended.

Very impressive but he isn't going to 'see' 87 or 86 or 89 on that tension tool.
Plus, knowing those rims, the tension is going to be + or - a fair amount also.
If it were me, I'd still shoot for 100 kgf(on my DT dial tension meter, 1.83 reading on the dial)..assuming it would be 'around' that but certainly no higher, as these 'can' pull eyelets out.

[weisan]

Master wheelbuilders in the house!

Mark, Old, Ergott pals...

We are so lucky!

[AngryScientist]

Originally Posted by oldpotatoe

Very impressive but he isn't going to 'see' 87 or 86 or 89 on that tension tool.
.

yea exactly. that math is cool and all, but the meter is about accurate to increments of 10 or so.

for rear wheels, shoot for 100 on the drive side. dont be afraid to go a little bit higher, the non-drive side - dont focus on the tension numerical value - whatever it is, it is to dish the wheel correctly, but aim for [relatively] even tension on all nds and ds spokes. front - shoot for even tension on all spokes.

[oldpotatoe]

Originally Posted by AngryScientist

yea exactly. that math is cool and all, but the meter is about accurate to increments of 10 or so.

for rear wheels, shoot for 100 on the drive side. dont be afraid to go a little bit higher, the non-drive side - dont focus on the tension numerical value - whatever it is, it is to dish the wheel correctly, but aim for [relatively] even tension on all nds and ds spokes. front - shoot for even tension on all spokes.

What POed-high-tech-guy said!!!

[Mark McM]

Originally Posted by oldpotatoe

Very impressive but he isn't going to 'see' 87 or 86 or 89 on that tension tool.
Plus, knowing those rims, the tension is going to be + or - a fair amount also.
If it were me, I'd still shoot for 100 kgf(on my DT dial tension meter, 1.83 reading on the dial)..assuming it would be 'around' that but certainly no higher, as these 'can' pull eyelets out.

The formula is just to give a ball-park number. The Rim Strength Constant C will vary from rim to rim, depending mostly on the alloy and temper, but also a little on the cross-sectional shape. So, as you say, there will be some variation from one rim to the next.

However, what the formula does illustrate is some of the factors that go into finding the optimum tension. For example, the 28 spoke GEL280 wheel recently discussed in a different thread might be okay with an average tension of 100 kgf. But if that model of rim with 40 spokes were used, 100 kgf average tension would likely result in buckling the rim before it even left the truing stand. If instead the 28 spoke rim were built with a Velocity A23 (450 grams), it could (and should) use a higher tension, perhaps 130 kgf or even more.

In fact here's what http://www.velocityusa.com/tech/rims/ says:

We recommend building to spoke tension between 110kgf and 130kgf. Each rim may behave a bit differently; the mark of an excellent wheel builder is the ability to find the highest tension a rim will allow while maintaining its radial and lateral true.

Because their Deep V rims are so strong, I've built 18 and 20 spoke versions of these rims with closer to 150 kgf. If you think that tension sounds high, look at the chart or recommended spoke tensions on the Park Tool web site, which lists recommended tensions up to 181 kgf.