Bicycle Mechanics - Poll: Do you use torque wrench on your bike?

I voted yes

Si. And I would have voted for Pedro too.

No for me. Good idea to do this poll, I've wondered about this, especially with all the torque wrench related threads lately-

I have one from my mis-spent youth with a couple of fast cars. So now I use it on my bikes. Mostly I use it when I attach cranks and want to properly torque the crank bolts. Otherwise, there's not a lot of other applications I use it for.

I voted no. I've got calibrated arms:D .

Seriously, I do own a torque wrench for working on cars. I would probably have to buy one with a lower range to work on bikes.

But I will also say that in my years of wrenching (not on bicycles, but in general) I've developed the "feel" for tightening fasteners. I'm not claiming to be better than a torque wrench, just that I've never felt the need for one for most of my bike work. I'll be the first to say that a torque wrench would be more accurate and consistent.

Yes, but not always/often.

i can see one on the cranks, and if i had a fragile frame like aluminum or carbon i could see it

but otherwise i never use one.

I asked for this, I estimated less than 1% of cyclists own a torque wrench. You'd have to poll the eternity to be accurate. In the meantime we have people (me included ) who are interested enough in making a bicycle work efficiently to take the time and post a comment on a bike specific web site. My estimate may be way off in this respect.

I don't own a torque wrench. After reading my Fox fork manual I believe I need 2 of the said wrenches. Apparently the aluminum nuts will simply fold and melt if you even think about over torquing them during the oil change process.

The thing is I see aircraft engineers torque very specific items by hand and end up being uncanningly close to the correct torque values. Professionals YES, but it must be the beer.

Also I have NEVER, EVER seen a LBS use a torque wrench. It may be a canadian thing but in 20 years I have yet to see a torque wrench in a USE in a shop.

NO.

Main reason is that on light weight or sensitive equipment you can still do damage with a torque wrench if you put all your trust in it.

If you haven't the feel for sensitive work a torque wrench may help but if you haven't the feel you probably won't have the awareness to stop when an inch pound wrench says too.

Other reason's are most of what I see on bikes isn't that sensitive and they're time consuming to use. I think all the torque wrench hullabaloo is mostly manufacturers covering their butt's.

I think all the torque wrench hullabaloo is mostly manufacturers covering their butt's.

When I picked up my fork, they guy that built it said "Overtighten these bolts on the crown, and you'll crack it right here, (he pointed) and this part is $90".

I use a torque wrench to pound in old nail-on cleats.

Also I have NEVER, EVER seen a LBS use a torque wrench. It may be a canadian thing but in 20 years I have yet to see a torque wrench in a USE in a shop.

But it's also a rare shop that I'd trust to do bicycle work for me. I just bought a Cannondale tandem and the LBS didn't do an amazing job of prepping it.

Sheldon

I know the moment arm of every wrench I have and I can judge weight pretty well, knowing that, it's not that hard to get torque down to 1-2 in-lbs below 20 and 4-5 in-lbs in the 50-60 range by hand. Plus I work with that stuff every day so you get a feel for it.

I have always guessed at this, but I've seen multiple sources that show pretty much the same thing as this site:

http://www.mettec.com/technical.htm

That is:

Method Accuracy
By Feel +/- 35%
Torque Wrench +/- 25%
Turn-of-nut +/- 15%
Preload washers +/- 10%
Bolt elongation +/- 3%
Strain gauges +/- 1%

This is CLEARLY a case of YMMV, and it does NOT speak to what level of accuracy is really important and on which fasteners on a bike, but ... I don't think that most calibrated arms ... really are that well calibrated.

[EDIT: I found another site with similar numbers, but with a better qualitative explanation:]

http://www.jamesglen.com.au/training/bolt-tensioning.htm AND

Their "manual" located at: http://www.jamesglen.com.au/brochure/JG_Training_Manual.pdf



Operator Judgement, tightening by feel, is the most common tensioning method for non-engineered and DIY type applications. It is generally satisfactory in these non- critical joints where loads are static and not subject to vibration; however, it is prone to significant under and over tightening by inexperienced operators.

Torque wrenches are by far the most common tensioning method for engineered joints because of low cost and simplicity, but at + or - 25%, they lack accuracy.
Approximately 85-90% of the torquing effort is used to combat the frictional forces in threads and mating surfaces of the bearing and rotating units; (stainless components can be even higher). Any reduction in friction will have a marked affect on the induced tension; ie. a 10% reduction could increase tension 80-90%.

Lubrication, thread fit, tightening speed, surface finish or plating, all have some effect on the friction generated. Close attention to these factors and to torque wrench calibration can improve accuracy.

The minimum lubrication required would be light oiling. The residue on plain finish mild steel and high tensile bolts is usually sufficient, but all plated products should be oiled and stainless steel products can benefit from a high quality solid type lubricant such as molybdenum disulphade.

Tightening torque figures to achieve 65% or proof load are shown in the James Glen Technical Catalogue for mild steel, high tensile and stainless grades.

Turn of nut is commonly used in structural bolting, but requires marking of the various components to verify the degree of turn achieved from 'snug tight'.

Time consuming, but does provide some evidence for subsequent inspection, as do load indicator washers - slightly more expensive for slightly more accuracy and permanent evidence.

Fastener elongation involving direct measurement of the degree of stretch along with strain gauges attached to the bolt shank, give excellent accuracy, but would only be justified economically in the most critical of circumstances.

Plus I work with that stuff every day so you get a feel for it.
Really? I thought you were a proctologist?

Or is that what you meant?







;)

Just bought a Ritchey Torqkey. About $20.00, never used it probably never will.

I don't have a torque wrench and never had a problem. But my bicycle is steel with aluminum components, if I had a CF frame and components I'd buy a torque wrench.

If you really wanna be anal and you know your moment arm is say, 6 inches, grab a 10lb dumbbell and rest it on the wrench, voila, 60 lb-in.

What you do now is, you weld a relatively weak piece of metal to the end of the wrench as the moment arm, use the original arm fo the wrench as the reference, calibrate a few reference points then attach it to a dial so you can see the difference on a dial and voila! no need for a torque wrench.

I voted no. I've got calibrated arms:D .
Same here!
I also had my hands & fingers calibrated for accuracy.

And someone mentioned lubrication. I always overhaul components and grease all the threads and under the bolt head. I even lightly grease the BB spindle before installing crank arms.
(2 exceptions; deraileur stop screws and canti arm mounting bolts.)
So that would have an effect on the torque specs.

In 30+ years as a bike mechanic, I've yet to strip or break a bolt or part.
Maybe I should get a Snap-On tattoo on my arm! :p

If you really wanna be anal and you know your moment arm is say, 6 inches, grab a 10lb dumbbell and rest it on the wrench, voila, 60 lb-in.

What you do now is, you weld a relatively weak piece of metal to the end of the wrench as the moment arm, use the original arm fo the wrench as the reference, calibrate a few reference points then attach it to a dial so you can see the difference on a dial and voila! no need for a torque wrench.

Much easier and convenient than buying a wrench. ;) I don't understand why someone would spend a couple grand on a bike, and if they do their own work, not spend the cash for real tools.

Much easier and convenient than buying a wrench. ;) I don't understand why someone would spend a couple grand on a bike, and if they do their own work, not spend the cash for real tools.

Because bootleg works just as well. :p

i don't, mainly cos most spanners and wrenches come in sizes proportional to whatever fastener they're designed to work on. hence 17mm spanners being much longer than 8mm ones. the only place i might use one is on the allen bolts for crank arms

I voted yes, but only for crank bolts/nuts.
Top

"Approximately 85-90% of the torquing effort is used to combat the frictional forces in threads and mating surfaces of the bearing and rotating units; (stainless components can be even higher). Any reduction in friction will have a marked affect on the induced tension; ie. a 10% reduction could increase tension 80-90%."

Which a mechanic can somewhat control by cleaning the threads throughly and applying the correct lubricant.

Cyclists can obsess about weight and type of components, but few use a torque wrench to actually insure these $$$$ parts are actually assembled properly. I'll put my order in for the "correct tools" soon...the only thing that worries me is the 3 bikes I have that have all sorts of uncalibrated torque values for every component on the machines. That's the expensive part....

50/50 so far, I am a bit surprised. What if the entire bikeforums membership voted?

What if the entire bikeforums membership voted?

I'd be shocked to see even 1%.