The installation instructions for bottom brackets might say that e.g. Octalink type bottom brackets should be installed using a torque of e.g. 435 lbs. This is fine.

But, to do the installation, the correct bottom bracket tool is required e.g. a Park Tool BBT-22. This should be held in place somehow, using e.g. the rear hub skewer to avoid damage to the thread by the tool accidentally coming out when in use.

The question is then: How can I measure the torque? A torque wrench can not be used when the rear hub skewer is occupying the center of the bottom bracket tool. I guess a normal wrench would be used, but this can not measure torque...

Any comments on this?

it doesnt need to be held in place, can also use the skewer and a crows foot

I've done it a few times on my own bikes with a big Craftsman torque wrench, and managed to NOT not slip.
- But I like your idea for using a skewer.... If you use a crows foot then, be sure to calculate the compensation factor 1st.
In retrospect, I'd also recommend chasing the threads before you begin.

Hold the tool in with the skewer until the cup is tight. Finish tightening it with the torque wrench, very carefully.

In the bigger picture, you really don't need precision torque to fasten an Octalink BB into a frame. The core concept is that the driveside, being the "fixed" side, should be fastened against the frame very firmly, and the non-driveside is mainly there to support the other end of the cartridge unit, so fasten it fairly tightly.

If you're truly lost as to what it should feel like, sure, use a torque wrench; a healthy BBT-22 will not cam out of the splines easily at 435 in-lbs if you pay attention to what you're doing. You can use a large quick-grip wood clamp to hold the wrench/tool to the BB if you have one that opens wide enough.

Thanks for all replies!

mechBgon: I read some instructions and from these I understood that the "loose" side was the most important side to fix properly because it would keep the fixed side "in place". Is this wrong then? From your post it seems that fixed side (drive side) is the most important to tighten properly.

The drive side is the more important side. The drive side's built-in flange should be tight enough against the frame that the tightness of the non-driveside cup is not critically important. If the driveside end of the bottom bracket does get loose, you may feel a "clunk" as it rocks around in the threads, and it may damage the frame if it's left loose long enough. An inch-pound of prevention is worth a foot-pound of cure...

It can also be helpful to secure assistance from a friend. Have them back you up on the BB on the non-drive side as you push and turn. I like to do it with both tires on the ground rather than relying on my bike stand. That also helps stabalize things. Or, lay the bike down on a piece of carpet or other soft surface, non drive side down. Most times when I have a problem with the tool wanting to jump out is because of poor back-up. The idea of a woodworking clamp is also a good one. They sell them with rubber pads. The important side to be firmly torqued is the drive side on cartridge style BBs.

Thanks for all your good replies and tips!

This is very I found the information that lead me to believe that the non-drive side was the most important side to fasten properly:

https://www.parktool.com/blog/repair-...et-service-bbt

At the end it states how much torque should be used to fasten the removable ring, but does not say anything about torque for the fixed (drive side). But I guess the article is probably a bit unprecise, because all your comments seems very reasonable to me.