A lot of crank bolts are in the 40's Nm, so up to 50 is a good place to be.

I use one of these for suspension and crank stuff, it has a good range and high accuracy at the ends of it's range so I can cover the whole bicycle spectrum with this and a smaller 1/4" drive one for bars, seatposts etc.

https://www.totaltools.com.au/...rench-model60-130101

Good tools last a long time and hold their spec better.
Not only that but ease of reading and setting values is a much more important part of torque tools than most people think.
Some cranks use a reverse thread so reversible is needed sometimes.

Many of the cheaper wrenches have 6-8% value errors.

What do you need a torque wrench for?

Your hand is free. And jimatbeyond asks the right question. Do you know the answer?

Coming from racing Motocross and enduro and doing my own wrenching I can tell you it was worth it for me. Bicycles are far more delicate and I was destroying stuff.

This. The anti torque wrench crowd is out in force saving us from the evils of what they feel to be unnecessary tools, there are only a few of them but they're very vocal. The argument is that torque wrenches aren't necessarily fully accurate, and torque specs don't usually mention if the fastener is to be dry, greased, or used with loctite. There's some truth to those things. Undoubtedly the anti-torque folks have well calibrated hands that can feel an appropriate amount of torque, but a lot of home mechanics don't. So maybe your actual torque using a wrench might be 10-25% off, maybe even a bit higher in some cases. But your uncalibrated hand might be delivering 50% or 200% of the specified torque. Back in the days of steel frames and sturdy alloy components nobody needed torque wrenches but a lot of today's stuff has a much lower margin of error.

I believe an apt saying for the anti-torque wrench crowd would be "letting the perfect be the enemy of the good."

40 nm is about 29.5 ft-lbs, not 350 ft-lbs.

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"...the street finds its own uses for things"

^^This^^

I think I have like 8 torque wrenches in different sizes and varieties. One was an award at a local tri. Probably one of the better product type awards I've received.

You need two torque wrenches, a small and a large. For smaller stuff the CDI Torque Control works well. It is 2-8NM, and CDI makes Snap-On's torque products. It can be found for $50 or so. For the larger one, if you don't want to spend a lot, a beam type will work fine.

No one will answer you because the people that think a torque wrench is needed don't have the basic knowledge to discuss/argue with you to start with.

Apparently few of us on this board that have the knowledge and experience to question the need are dismissed out of hand for some reason. The OP didn't even know how to convert from nm to ft-lbs. It is unlikely he will be able to care for the tool or have any idea when it is damaged or not working correctly. Then when something comes lose or fails he will blame the manufacturer.

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"...the street finds its own uses for things"

mainly crank

Hope you aren't in charge of putting anything important together.

Like aero engines, landing gear, the wheels on a truck, or fair ground rides.


https://www.google.com/...uk/news/5095592.amp/
Take a look at this.
There just happened to be no torque wrenches at this park either at the time the ride was assembled.
🤔

 Tighten crank bolt to 380-410 kgf.cm / 38-41 Nm / 337-363 in.lbs.

I assume the answer he's going for that using a tool that is more precise than 'feel' alone. Your response suggests that your hand is more accurate (and cheaper) than a torque wrench. I agree on cheaper, but couldn't disagree more on precision.

I understand you have a lot of experience/expertise with this measurement of Torque, but I'm not clear why you assume that 'feel' is somehow superior to a torque wrench. Sure, torque wrenches are less precise than other tools, but if you combine 'feel' with lack of experience and your certain to get less consistent and precise outcomes than using a torque wrench.

Plant Manager of an Aero-Space company. 22 years in the Navy operating a nuclear power plant. Those places use torque wrenches. Those people are trained to use torque wrenches. Those wrenches are controlled and calibrated. That assembly and maintenance is on a level you could not comprehend.

Crawl back in your hole, or start a fight on the internet about something you know something about.

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"...the street finds its own uses for things"

I'm an anti-torque wrencher. 20 years in measurement science. Precisely for the reasons mentioned concerning calibration and thread condition I consider torque wrenches useless. If you're working on your own bike choose well-designed robust components that aren't sensitive to reasonable torque variations.

What about should 40mn feel like

I guarantee that if you take 20 bike noobs, and give them no detailed instructions, and have them install a carbon stem + faceplate, their faceplate bolts will be all over the place in terms of tightness, from dangerously loose, to part-damaging tight. Not all carbon parts require such care, but it's really easy to get it wrong (permanently) in this area without a torque wrench.

If you have folks coming from experience with alloy faceplate and stem installation, they'll almost invariably torque it wayyy too high (yep did that) based on their experience with the alloy.

I was horrified at how off I was with my installations once I got a torque wrench - luckily, I had purchased the wrench right before doing the carbon install - my alloy faceplate bolts were over 2x the recommended tightness, which almost certainly would have broken the carbon pieces.

To actually answer your question....

I have 2 - a Park Tool TW-5 for the small stuff, and their set of bits that I've had for 15 years now and looks / works as good as the day I bought them. Use for seat posts, bars and chainring bolts (essential to get right torque for power meters).

Then a big mother ^*^%*%$ I got from the local car parts store for the single side bolt on crank (85NM). I swapped over the quarq betwene road and TT bike 2-3 times a week for 5+ years and never had the cranks fall off or needed a new bolt (as a result of overstress from all the swapping).

Now I'm in late 40s now, been building / fixing own bikes since I was a kid, and of course never had a torque wrench for most that time. But then had a seatpost bolt shear on me as I'd over-torqued that, and then some tri-bars that kept slipping but had the tiniest little bolts I was sure would strip as soon as I waved an allen key near them. So the TW-2 was a huge help in making me confident I wasn't going to have to repeat the 30mile ride home stood up with the saddle spinning and smacking me in the inner thigh every 2 mins, or the bars falling out 140km into the ironman (as they did on the course recce).

So for 99%+ of the bolts I've done I've been fine without the torque wrench. But the tiny minority I got wrong have been a huge PITA (literally in one case). So I'm happy to admit I'm not some freaky mechanical savant who can perfectly judge torque by smell, and I enjoy the confidence of being able to just go out and ride without fear. I also have a much better feel for if anything does happen on a ride what the right pressure is to put on a part to get my clubbies home safely. It's surprising how many tri club and cycle club group rides end up with someone's bars / saddles slipping, and normally after they have done some maintenance / fit themselves, or a bike shop has done that for them.....

Except I did draw first blood.

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"...the street finds its own uses for things"

I'm a manufacturing engineer at an aerospace company. Knowing how carbon parts are made, it makes way more sense to have people use a torque wrench for most applications. Yes, there will be some failures, and not all parts need one, but it's way better than just telling people with no prior knowledge to go by "feel" when they dont know how it should feel. You end up with most people right around the correct value with maybe +-10% scatter. Way better than what you get otherwise with some people tightening the hell out of it, and others barely tightening it at all. Also, it's a torque wrench, we're not exactly talking about a complicated measuring device here.

Before you start trying to take the high road with how smart you are aerospace is one word and neither aerospace nor manager are proper nouns and need to be capitalized. It really undermines your argument.

I have 20+ years in calibration and instrumentation with an automotive component supplier. We use torque wrenches for everything that has a torque specification. Once a year we have training, people don't think they need it until we let them tighten things and see how far they are off.

Stripping threads on a $10,000 part is a problem we want to avoid. Incorrectly setting preload on a bearing causing premature failure makes our product less valuable.

I also have a few CDI and highly recommend them. They come with a calibration sheet and you can send it back for calibration every once in a while. Make sure to set it to minimum calibrated torque (not zero) during storage.

For small bolts and travel I really like the Silca torque set

My famous last words before destroying the threads on some very expensive parts made of aluminum.

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Adrian in Vancouver