FOUND: 9point8’s Torque Keys Make Proper Bolt Torque Affordable & Easy

What a cool idea. Maybe not quite as accurate as my Snap-Off wonder-gadget, but hey, close enough for most things. I’m in.

I have a very similar tool from Topeak that comes with interchangable bits. Costs less than two of this keys and works great for me.

Canyon gives you one of these for free with your bike in order to assemble it properly. Theirs actually one ups this one by having a set of standard sized replaceable bits to use on all the different sized allen and torx pieces possible (up to 6mm, I think, though you could use adaptors for anything bigger I suppose).
I’m surprised not to have seen more of these, though. Torque wrenches are otherwise way expensive for idle tinkerers especially when they have different torque settings and bits, though admittedly more and more necessary.

Cool, now I can use a $10 torque wrench to avoid breaking my $300 handlebar.. because, you know, $45 for a proper torque wrench is just so expensive I can’t afford it.

@goridebikes – If you don’t know how to use any torque wrench correctly, you still can break your handlebar!

It’s a great idea but there are serious bias problems related to the usage of this thing:

1) It cannot be precise since it is measuring off of an already twisting beam (deflection bias)
2) How about if you can’t see the bottom of the wrench? (ambivalence bias)
3) It will only work with one single grade of steel from one batch because another batch will have a different Young’s modulus, which will also vary with usage and time.

Spend the $50 for a real torque wrench.

Maybe I’ll get flamed for this, but you gotta be pretty ham-fisted to break parts on a bike for lack of a torque wrench, even carbon stuff.

@ Chris S –
Concern no.1 – Its repeatable if one uses the same intersection point of allen key to scale. Is it ultra precise. Probably not, but I don’t think its far enough off to matter.
Concern no. 3 is ridiculous. Tool steel is made to a standard. Small variations from batch to batch will not adversely affect young’s modulus to such a high degree that accuracy will affect bike installations. Its a bike, not a precision bolt. Variations in the bolts, bolting surface, lubricant used probably affect bolt stress and clamping force more than any variation in varying steel batch’s young’s modulus.

i like it because it’s good for hard to reach configurations where other torque instruments i have won’t fit well (e.g., saddle clamp bolts on some seat posts).

I use the toppeak torque wrench. It includes all different sizes and is $25-30. I use it all the time and is accurate as I have used an actual torch wrench to test it out.

@Chris: The Young’s module (stiffness) of steels are almost all ~210GPa and does not change over time. All these keys are made of steel with the same dimensions. Therefore this is a very simple and accurate way to measure torque and never needs to be calibrated unlike “normal” torque wrenches.