gululok

I've been learning to work on my bike from youtube videos, and I've bought some specialty tools like cone wrenches and such. A small torque wrench seemed like an unnecessary expense, but I've just stripped out the pinch nut on my front derailleur today. Is there some tricks or visual cues that helps indicate the proper torque? Should I just get a small torque wrench?

ThermionicScott 

$20 isn't a lot to spend for a beam torque wrench, and I use mine on all kinds of things.

blamester

The thing about the youtube videos is they can't teach you experience or how to hold and use a tool.
Go slowly. If it takes a bit longer to do so what.
If you think about it stripping that bolt is ridiculous because you could have tested it before you stripped it by seeing does it hold.
And torque wrenchs are not the solution to every stripped bolt because it could be the installation is wrong in the first place. So you end up stripping the bolt anyway.
Go slowly. Mechanics are not born they learn.
And everyone messed up at some stage.

rm -rf

I had no feel for how tight 5 Nm is. Or any other torque specification. So I got a small bike oriented torque wrench. (which is only for small bolts, big Nm numbers are out of it's range. For bigger torque, I had a long beam wrench already, but the Harbor Freight cheap torque wrenches seem to be reasonably accurate.)

Now I can tighten the two stem pinch bolts or the four front plate bolts with my Y hex wrench and a reasonable finger force, since I now have some idea of the range of effort. It's not obvious how to learn this without a torque wrench or learning from some failures along the way!

But bamester has a good point. It's not always necessary to tighten to the specified torque. It depends on the component. How critical is the torque for that item?

For stem bolts that hold the stem to the steerer tube, I'm often lower than the spec. It just has to hold the steerer and not slip. BUT--overtightening a carbon steerer tube can permanently damage it, requiring a new fork.




Seatpost bolts are similar. I use a piece of tape on the seatpost to monitor if it's staying in place or slipping a bit.

I did use a big torque wrench on my cassette lockring, to get a feel for the high torque spec, about 40 Nm, I think. But now I use my long handled cassette tool and just pull it to what feels like a similar torque. The cassette just needs to be held in place without play. I think there's a fairly wide range of acceptable torque for this lockring.

I still use a torque wrench on my crankarm pinch bolts. I don't do this very often, so I'm never sure of the feel. These need to be quite tight, but not overtightened. And I want both bolts to be the same torque.

andrewclaus

I just salvaged a couple of bike-specific torque wrenches from a box of tools donated to the non-profit where I volunteer. It was interesting to check some of my guesswork. My guesses at 5 Nm on my stem were pretty close, around 4 Nm. 12 Nm on the seat post clamp was around 10 Nm. As mentioned above, on my own bike it's easy to err on the side of caution and monitor during use. And it's all alloy so I wasn't too worried. If it were carbon, I would not have guessed.

I have a lifetime of amateur auto and bike mechanic work behind me, much of it with a 1/2" drive torque wrench. I use it religiously on auto suspension and engine work. But I just don't see the need to buy special bike tools for low-risk items on my old, inexpensive bike, where I trust my skills and judgment. I'm also a retired engineer with a lifetime of experience with metric units, and can estimate force and distance on levers pretty well.

I use the shop torque wrenches on the nicer bikes we see there, especially on high-risk items like brake discs and handlebars.

I also take good care of threads. I clean and lube old threads where needed. I make frequent use of tap and die sets. I made a thread chaser for my crank puller, for instance, from a broken tool. I've stripped a few over the years, so I feel the pain when it happens to someone else.

canopus 

You can get a 1/4" beam type at Oreilly for 26
https://www.oreillyauto.com/detail/c...e+wrench&pos=9

or Cheaper on the Bay
https://www.ebay.com/itm/14295862546...IAAOSwn1FbskEY

tendency

As others have said it takes experience. Personally, I know very few (if any now that i think about it) pro bike mechanics that use torque wrenches; I simply don't think bikes have the complexity to warrant one however, of course, that's just my opinion. I don't use one myself and never had an issue however there's years of experience involved and I used to be an auto mechanic and learned much from that experience.

General rule of thumb: bolts/screws etc. need to just be tight enough to stop squeaks and prevent them from coming loose. Easier said than done . Another general rule of thumb: if something squeaks on a bike it either needs further tightening, lubrication or both.

Just wrench away you'll learn and, as others have said, undoubtedly break more things in the process. That's how us humans learn. It's fun.

Dan Burkhart 

...

squirtdad

There are a lot of options out there, the consensus is if you are working with carbon a torque wrench is a must.

I don't do carbon, but ended up getting a Park ATD 1.2 for small bolts and a beam for bigger things, I found the beam usable but not convenient so I got click type 1/4 (pro bike tool from amazon....think most like this are made in same factory in taiwan)

I have found that I was surprised at how much more torque things took than I was doing, especially cassette lock rings.

70sSanO

Everyone has provided good examples, especially noted is carbon fiber components. The quick and dirty answer is feel for most small fasteners.

My one piece of advice, if you decide to get a torque wrench for small socket head/torx bolts… don’t even think about getting a beam torque wrench. Big stuff like lockrings, square taper crank bolts work fine.

Beam torque wrenches rely on a clear and straight visual reading of the guage. While I don’t use a torque wrench on a saddle attach bolt, or a RD pinch bolt, I can’t envision using a beam torque wrench.

I have micrometer torques wrenches, but if you decide to get a small fastener torque wrench, get an adjustable T hande. A range of 2nm-12nm would probably cover all the stuff you are concerned about.

John

blacknbluebikes 

best $80 I have spent. BBB btl-73 Use it for everything.

davidad

At 60 pound feet my back pops!

Barry2 

I'm not a pro.
I don't have the experience.
A torque wrench is cheap insurance for the welfare of both my carbon bike and myself.

Barry

fooferdoggie 

for 70 this guy has its own bits though its missing a t20 I use it all the time.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

c_m_shooter

Tighten it til just before it breaks....

thook

lots of great suggestions and support. i'd just add my 2 cents, if you want a torque wrench, go to or order one from harbor freight with a 1/4 inch drive that measures in inch pounds. they're not very expensive and easy enough to use with most any task on a bike requiring care on tightening. eventually you'll get the feel for how to tighten things, and the clicker wrench will help with that. bar types are probably better for getting the feel, but as someone pointed out if you're tightening something sometimes the wrench can be at an odd angle to read easily.
just remember a rule of thumb, the smaller the fastener/bolt/screw and finer the threads, the less torque it takes and the easier it is to stress the threads. things like crank bolts, pedals, seat post clamps, threaded headsets, brake calipers, etc all have bigger thread and fasteners because they need more torque to stay in place. oh, and while your getting a torque wrench, be sure to get a metric socket set ...hopefully one with some added allen head drivers

thook

lol...sometimes you break it finding that point. no bueno. ( i did that recently. bummer)

Riveting

I use torque wrenches at work a lot, and by feel I can torque to a smidge (1/16 to 1/8 turn) below 30 in/lbs (3.39 Nm) quite reliably, and then finish with the torque wrench. Unfortunately, almost nothing on a bike torques to that value

Barry2 

OR

Tighten until it strips, then back off 1/2 turn.



Barry

Pantah

A torque wrench is a great tool to teach you how to get to the point where you can do it by feel. There are certainly things that absolutely need a torque wrench, however I haven't encountered that on bicycles. Still, good to have one on hand.

Something a friend's dad did way back in the day to teach himself how strong a given size bolt was is he clamped a bolt in a vice and cranked on it until the head snapped off. Did that several times with the same and different size bolts, as well as clamping a nut in the vice and threaded the bolt in that until either one stripped or the head broke off, and he got a very good idea of what was too tight.

drlogik 

A reasonably priced torque wrench is cheap insurance and will pay for itself on the first part or bike that you don't break.

Some, not many, but some very experienced bike mechanics can feel within pretty tight tolerances torque settings that they do over and over again. Each part and each bike is different though.

Back in the day (mid 1970's) in the shop I worked in we didn't use torque wrenches on anything unless it was Campy. And stem bolts, cotter pin nuts and brake cable and derailleur anchors were the only things that I had enough repetition with that I could do by feel. I don't have that "feel" much any more because I don't do it enough.

Most tools are not an investment. They are a depreciable asset. Torque wrenches are an investment. They pay-forward parts that don't get ruined by over-torquing.

If you don't know what to get, buy a Park torque wrench. Yes there are better for more money, but they are reliable, pretty accurate and reasonably priced.

easyupbug 

Good thoughts above but I caution against Harbor Freight unless you are comfortable with calibrating. After a neighbors bar slipped down on his newish carbon bike he asked me to look at this stem/bars which were fine so I had him show me his torque wrench. It was seriously out of calibration and should not have been used as it was out of the stems range anyway, he had the receipt so off we went. The clerk got the manager for us and when I assured him we had calibrated the wrench correctly he said wait to bring it back until after they have their upcoming parking lot sale at which time they will sell off the current defective (my word) inventory and get in a new batch which should be better. Neighbor was lucky it was reading high as low could have caused a on road failure which at best would be exciting.

70sSanO

Micrometer click type torque wrenches, just like spoke tension wrenches, rely on a spring for measurements. For click type the spring holds a ball in a detent until the force for the setting forces/releases the ball.

The problem is there is no way to know if the actual force, torque applied, is correct. It is possible to test and sometimes calibrate a micrometer click using a digital scale at a certain point on the handle. This will get you close as there is a compounding of tolerances between the measuring devices.

I spent a couple days testing my torque wrenches. One really old one can’t be calibrated unless sent to company that is no longer in business, on another I was unable to get the hex nut to budge. I basically put index cards on the variances in each case for 8-10 different settings. I also tested the wrenches against each other.

For a Park style T handle, I believe it can be sent back to Park, like the spoke meters, for calibration. You could do a comparative test to a known calibrated torque wrench for reference.

My guess is that over time and use of mechanical springs will weaken them and the torque will be lower than the reading. Leaving a torque wrench set at torque will probably accelerate this, I have no clue to what degree.

John

Chuckles1

I bought a small torque wrench and accessories for use on my bikes. After using it for a while, I decided it's usually unnecessary. Allen wrenches are sized, like most wrenches, to be a proper length for the size of the fastener. Try putting to much torque on one, and you'll feel it stabbing you. When in doubt, a torque wrench can be helpful. I used to set a minimum torque with torque wrench, then snug slightly with a hand held Allen key just to verify that going by feel is accurate enough. For higher torques, a torque wrench is more important, I find.

Vintage Schwinn

As others have already said, a Harbor Freight TORQUE WRENCH costs peanuts.
Back in the 1970's, you would have paid possibly more in unadjusted 1974 dollars for a used one, as new ones at Sears, Western Auto, Otasco, Coast to Coast Hardware, and all other possible stores including Kmart carrying such an item as a TORQUE WRENCH at that time would likely have been at least $30+ in 1974 which would translate into well over $220 in todays (2021) dollars.

You are a silly fool if you want to just wing it and guess on a CARBON bike! It is a bit more critical than say for a STEEL bike where you might be able to provide excess torque which doesn't yet eff-up something beyond repair. Don't be a bonehead who decides on choosing top-quality machinery to ride, but yet wants to continue with a Caveman's big log and large rock approach to beat it into adjustment. Don't be stupid! The $20 that you spend on the Harbor Freight TORQUE WRENCH will be well worth it. The quality of that tool is surprisingly good, and definitely much better than the least expensive torque wrench from forty plus years ago which did cost a helluva lot more than $20 back then.