Is highest possible spoke tension the goal?

[RTM]

I just built a set of carbon rims, recommended tension is 120-180kgf. I've got them perfectly true right now at around 115-120. Should I crank down the nipples and shoot for higher tension? Right now it feels good, and more tension is requiring a VERY firm twist of the spoke wrench and spoke twisting is becoming an issue.


- Rob

[solomon707]

Do you know what the tension spec for your hubs is? If memory serves, even CK disc mountain hubs (pretty sturdy) are only rated to 120. My suggestion would be to stay at the bottom end of the rim's range. Generally, if the spokes are fighting you, you should stop.

[One Pivot]

180 kgf is their max spec?? Are these proprietary spokes and hubs, or standard jbent steel spokes?

Whats your NDS tension? High DS tension is really for the benefit of higher NDS tension. Also keep in mind a lot of rims are built as low as 100 kgf and they tend to hold up. Your 120 is more than likely fine. I like being at the top of the rim rating, but ive never had a rim rated for more than 130.

[Le Duke]

I have to ask, what do you hope to gain by going higher?

[RTM]

I have to ask, what do you hope to gain by going higher?

I had no idea if there IS anything to gain. That's why I asked.

The rims are Light-Bicycle carbon. Wheelsmith DB14 spokes (2.0/1.7). Wheelsmith 12mm brass nipples. Hope pro 2 evo rear hub. I've built other wheels and these do feel right at 120 but I wasn't sure if high tension was something to take advantage of or not.


- Rob

[derby]

With my Light-Bicycle CF 650b rims I tensioned 3 cross DT Competition 2.0/1.8 DB with alloy nipples to 135/140Kgf dished with Hadley hubs. About 5Kgf tighter than previously possible without cracking the spoke holes of my previous alloy rims.

The lateral flex test between the seat tube to wheel is feels very much stiffer with the CF rims. I could go tighter in tension but I'm concerned with hub durability.

With CF rims, the spokes or hub become the "weakest link" of the wheel's durability. I think current hubs are designed for alloy rim spoke tension, and could have durability problems if much higher spoke tension is used.

[beanbag]

In general higher spoke tensions are better because wheel failure occurs when spokes go slack. The limits are spoke hole pullout, radial collapse of the rim, and excessive spoke twist. I have heard wheelbuilders claim that as you reach a certain tension, the wheel becomes much more sensitive to the spoke adjustments, so at that point you should probably stop.