Cyclist0108

My older kid is getting a carbon bike, so I am thinking it is time he owns a torque wrench. To put it gently, he is a bit mechanically naive. (He also lives on is own now, so I can only offer my cheerful and engaging help and encouragement remotely.)

What might be the best low-torque wrench, in terms of preventing accidental over-tightening? The ones I have are essentially socket wrenches that you set to the claimed value in Nxm, and they click when you reach the appropriate torque. But I also am realistic enough to know that these things aren't fool-proof, even if calibrated correctly, and if you don't slacken the spring during storage, even an initially accurate calibration can't save you. Also, depending on how you do it, it is possible to miss the click, and having a qualitative sense of when you might be going too far can prevent a tragic outcome.

Would a beam torque wrench be better? (At work, we use these on shared equipment, like ultracentrifuges, where user error could lead to a major disaster.)



Other ideas or suggestions?

(Before I get a lecture on bad parenting, my youngest kid has become the most competent bike mechanic in the family. People differ.)

MudPie

If you think he'd be mainly using it to tighten and check stems and seat posts, these preset ones might be fine:
https://www.trekbikes.com/us/en_US/e...rench/p/08370/

Cyclist0108

Thanks very much for the suggestion. Those look ideal. The bike he is getting is a Trek, so that it is likely one of those (probably 5 Nxm) will be what he needs for the seat-post (my primary concern).

HillRider

I'm a big fan of beam-type torque wrenches. They are less expensive and not subject to going out of calibration unless you actually bend something. Damage is obvious because the pointer won't be at zero with no load and it can be bent back to zero if it is damaged. Their only dpownside is you have to be able to see the torque scale but that's almost never a problem when working on bikes.

woodcraft

https://www.amazon.com/CDI-Torque-TL...9041556&sr=8-1

veganbikes

This is the one I use for quick stuff that I don't need a ton of adjustment: https://www.parktool.com/product/adj...Torque%20Tools

aggiegrads

For ultimate “fool-proofness”, cam-over or break-over is the way to go, but they increase the cost 5x.

Unfortunately, if someone hears a click and keeps going, that is exactly the type of person that needs to be trained well to work with nice tools. I have managed hundreds of high-tech assemblers building multi-million dollar equipment, and we have invested extensively in break over torque wrenches. It only takes one sheared off bolt head to pay for many expensive torque wrenches.

All of that said, I would go with beam type or a small fixed with a loud click mechanism.

Barry2 

Harbor Freight has a 5-80lb 3/8” click type for $20.
It does the job and I’ll never wear it out.

Barry

dsbrantjr

The advantage of this kind of tool over a beam or click type for an inexperienced operator, is that it is impossible to overtorque the fastener as the tool releases at the set torque and will go no tighter. There is no way to ignore it and continue cranking the fastener like with the others.

dsbrantjr

That range is too high for many bike fasteners. Typical is 5 or 6 Newton-meters which is ~3.7 or 4.4 ft;lbs. It is good practice not to use a torque tool at the lower 10% or so o its range for best accuracy, which is stated as a percentage of full-scale.

SlvrDragon50

I mean that's true but at the same time it's kinda silly. While it wouldn't be useful on say a stem or saddle, it would certainly be useful for the crank when you are doing like 45 Nm. That's why I recommended the Wheeler torque driver in combination with some HF specials.

vane171

For those that are new to torque wrenches: I experimented with my click kind torque ratchet wrench before using it on my bike - I looked up nice big bolt in my place that would take some beating and applied the wrench and got no click in the wrench setting range of 2.6 to 16 Nm. It turned out, I was over-tightening way past the set torque. Once I figured that out, I found that a more reliable way than listening for a click is to watch the wrench head - it 'tilts' in the handle when at the set torque.

You can get familiar with how it works by setting the wrench at low torque, like several Nms, and putting the pressure on the head of the wrench with one of your hands while you hold the handle with the other. You can see the wrench head tilting and hear the click.


Watch for the wrench head tilt in the handle.

The tilt is pretty obvious, more so than the click.

-------------------------------------------------
Real reason why I am posting is, I am not clear on the torque setting markings on the wrench handle, the manual I got with the wrench is totally useless.
Which one of the two pictures shows the setting of '20' (inch pounds here but that doesn't matter here what units those are)?


Is this setting 20?



Initially I thought this is 20 but think the first image is right setting.

daoswald

https://www.amazon.com/dp/B015DJGECA..._5tlXEb5VJ5E1Q

This one from Ice Tools.

It is a beam style, and is super easy to calibrate.

I don't know that "fool proof" is a selling feature for a torque wrench. They're all pretty simple to use. And I can't imagine there existing one that could actually be too hard, even for a fool, to use.

Anyway, I use this one frequently in the maintenance of my two bikes, my kids' two bikes, and the neighbor's kids' bikes. It's sturdy enough and no less fool proof than any other.

SethAZ 

You don't feel that? I never actually listen for a click, nor look at the head. When it breaks you feel it in the handle. It's been that way with every torque wrench I've ever used.

aggiegrads

You are correct. The first image is the right setting for 20 ft-lbs.

phughes

I have an assortment of good torque wrenches for different torque ranges, the click type, and one beam type, but the one I use the most for the bicycle is this one. Something like it and a beam wrench, though I prefer the "click" type, would cover everything he would need, but the small one pictured, 5NM, is probably more important and useful on the bike.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

robertorolfo

Can we talk about why the torque wrench clicking off is such a relieving and satisfying sensation? I guess the reasoning is actually quite straightforward, but does anyone else enjoy the click so much? Have I just been traumatized by fear of stripping the very low torque parts on bikes, and the very high torque parts on motor vehicles (like the 180nm axle nut on my motorcycle that makes me sweat just thinking about it)?

I always immediately double check my torqued bolts, half to make sure everything is correct, half to enjoy the click again...

vane171

Now that I know what it is about, yes. Still the hear or feel the click in the handle failed me when I first tried it on various nuts - and when I didn't know yet what to look for visually. I even thought the wrench was a dud and I'd better find some bigger nuts around my place because it was clear, I'd strip those smaller ones while trying to hear or feel the click.

Now I could feel dumb but I am actually pretty good at all things mechanical and I shudder what 'normal' folks might do if they got their hands on torque wrench. I never had one, I always used common sense and a feel for the materials and I suppose I could continue doing that on the fancy bike I got. Usually nothing tragic happens if you under tighten, you just tighten some more until it works and continues working. But I can see the usefulness like if you take apart your car engine and during assembly you need to tighten bolts that you won't have any easy, reasonable access to later on.

SethAZ 

I too really love that click. It's a feeling of something like relief for both very low and very high torque bolts and nuts. I just installed a carbon handlebar on my bike, and having read articles and watched so many videos on carbon handlebar failure being caused by overtorquing the stem clamp, I chose a torque near the bottom of the recommended range and felt some relief when they clicked over.

The lowest torque I've used was 2 NM for something on my bike, and I'm trying to remember what it was. The highest torques I've ever had to do were the "Jesus nut" on the OH-58 helicopter I was trained to fix in the Army (something like 450 ft-lbs) and the crankshaft nut on my old Honda Civic (I forget the torque value, but it was pretty high, and breaking it required some kludge using jackstands, a 1/2" breaker bar, and a long cheater pipe slid over it).

SethAZ 

I guess it's one of those things that, once seen, you can't unsee, though if nobody ever showed you or trained you in its use it could take a while to figure out what it is you're looking for. I was trained in the use of torque wrenches by the Army when I was 18, since every single nut or bolt on the helicopter I was trained to repair had to be torqued to a specific value during reassembly. I went years and years working on my cars and bikes with no torque wrenches of my own, stripped my share of nuts or bolts even though my "feel" for torques was probably better than average, and now I've got torque wrenches because with smaller, thinner, more fragile parts like carbon handlebars, seatposts, what have you, it's become more and more important not to overdo it.

blacknbluebikes 

I can't recommend this more highly: BBB torqueset
It has much higher utility for me because it comes with the most appropriate hex bits included in a zip-up case. That makes it one-stop goto for pretty much all my hex-head adjustments, and if I'm throwing the bike in the car, that goes in, too.

squirtdad

the park like this will do 95% of what you need to do......i supplement with a beam for crankbolts and and cassettes

bldegle2

You want to get a torque wrench like this one https://www.harborfreight.com/14-in-...nch-63881.html, it is calibrated in inch pounds, not foot pounds, bikes are delicate creatures, they need to be cared for carefully...

robertorolfo

Wow, 450ft-lbs seems super high. How big was the wrench you were using? What type/brand of wrench does uncle Sam spec for a job like that?

I also remember once pulling a hollow parking post out of the ground to put on the end of my breaker bar as a cheater pipe... the things we do!

SethAZ 

For torques listed in foot-lbs sure. For torques listed in newton-meters that introduces a layer of conversion for the user, which isn't hard, but it's just one more thing for people to think about, and if they're new to the concept of torques it's just one more thing that could go wrong. Given the vast number of torque wrenches available denominated in newton-meters, and most bike-related torques being listed in newton-meters, I'd think the best advice would be to just get one.