sleepystarz

Ed, I definately agree with that. I know my local LBS doesn't ever use a torque wrench. They always set bikes up very nicely too Although... it is very nice to use a torque wrench on your own machine that you will put much more care into than a bikeshop that has to work on random bikes everyday.

Also, I whole-heartedly agree with your statement about "feel" and "cross-threading" Those 2 things are so important, and no matter how many tools you have... it's still a big asset to simply be comfortable working on the bike (or whatever else), and not doing stupid things like breaking bolts from not seating the wrench properly, cross-threading bolts, and simply having that "feel" for tightness when you aren't working with a torque wrench. I just have a soft-spot for this sort of thing because my friend always talks about how much he knows about working on cars, but he ALWAYS has problems with breaking critical bolts. We both work on the same make/model of cars and both did engine swaps, but his project was an endless headache and I had to help him through all of it.

Oldtrek - Yup, I don't really trust electronic ones, and they're so expensive too. $300 and up for those snap-on ones. I think the only thing that could be done to make sure they're working right is to send the damn thing back to the manufacturer for re-calibration every year or two.... definately not very convenient for the price-tag that comes with it.

Billy

Mr Zippy

I'd almost be prepared to go the otherway - torque wrench use on a bicycle essential, non-essential for your MG. I'd think that the threads on your MG would be far more robust than those on bicycles, in particular when you are tightening steel bolts into aluminium threads such as those in the bicycle frame. Torque wrenches help you to know that you're neither under or over tightening.

All the Shimano assembly instructions for their groupsets list varying torque values for different bolts, which I think also could be another endorsement of using a torque wrench.

Some bicycle shops might not do it because it would cost them extra time to be as precise, or they're still following old mechanic practices, when the robustness of cycling parts were greater, but, of course, much heavier. Unfortunately the "we know better, we've been doing this for years" attitude can persist even when the manufacturer of the part, who would have to know better as they know the tollerances they're designing to, doesn't endorse the practice.

sleepystarz

Interesting outlook. I don't really agree though ~~ Sure the cylinder bolts and threads may be more robust on the MG compared to a bicycle, but they are that way because they see much more power and stress than a bicycle ever will. That's why they are made with stronger bolts and higher torque values. Something has to keep that cylinder head bolted down. I understand your point of it being harder to screw up the threads on a cylinder head, but many engines do have aluminum heads with steel bolts being tightened into them.... and it is also very critical to tighten those bolts correctly, and in the right pattern. Bicycles aren't too bad because most parts only require a bolt or 2. I feel it is definately essential to use a torque wrench when working with critical engine bolts.

Using a torque wrench to avoid under or over tightening a bicycle bolt is a great thing... but if you don't have one just look at the size of the bolt and the materials being used, and with common sense you can get a good idea of how tight to go. Always try to learn from your mistakes too

ridesoldtrek

Keep in mind that using a torque wrench for engine head bolts, which are usually referred to as power bolts, is partly to make sure the the bolts have the right amount of stress to keep them from coming loose through the heating/cooling cycles an engine sees, which would happen if they were not tight enough, not necessarily to keep someone from overtightening. It also keeps the head gasket sealed under the varying loads when things are hot, then cold. Holds true for connecting rod bolts, and other high stress items.

But I guess that's off-topic. The comments on feel are very important. Using a torque wrench can help you develop that too, IF you are paying attention - which is always the case.

Retro Grouch 

In an automobile head installation, it's important for head bolts to be evenly tensioned to protect the head gasket.

Some carbon handlebar manufacturers recommend not using four bolt stems. I suspect that's because they doubt the average bike mechanic's ability to tension the bolts evenly without using a torque wrench. If the bolts aren't tightened evenly, it can put a point load on the handlebar and cause it to fail.

I've had the opportunity to work in a number of different bike shops. The ones that I thought were better-than-average all had torque wrenches and used them. The others didn't.

DocRay

Carbon+"feel"= broken carbon.

sngltrackdufus

on the "Head gasket".

Pete Hamer

I use a torque wrench at the shop. I know that a lot of other local shops use them too. I have three styles. This is a link to my local forum that I posted pictures of my torque wrenches on.

https://www.morcmtb.org/photopost/sho...2&limit=recent

The digital one recalibrates itself when you turn it on and has an error message if it knows that something is wrong. If you doubt that it is working you can check it against another torque wrench, like a beam style,(the shop owns one of those) to be sure. I can also have the snap on guy check it, he comes by once a week. Torque wrenches are critical on many bike parts. There is no way that you can know that you got the Shimano Hollow Tech two crank arm pinch bolts to 12-15nm without a torque wrench and it is critical that you torque them properly. Alot of people say that they have never used a torque wrench and never had a problem. I think that they don't realize that the problems they have were caused by incorrect torque and they just blame the manufacturer. It's also nice to have a torque wrench to check a damaged thread to make sure it can handle the recommended torque without failing. Torque wrenches aren't fool proof though, you need to have common sense. I wouldn't trust a bike mechanic that doesn't use a torque wrench.

As far as a torque wrench recomendation. For home use I'd just get the Park beam style. Accurate if used right and inexpensive.

DannoXYZ 

The main issue with shops using torque-wrenches is liability. A lot of beginning mechanics do not have the "feel" down yet. They tend to overtighten small bolts and undertighten large bolts. The brake-cable clamp bolts are always a major concern as overtightening them will strip the threads on the nut and there'd be no tension on the bolt at all. At my shop, we had a build-sheet for every bike with about 10 areas that needs to have the torque-values recorded and signed before the bike can leave the shop. After we implemented that, the rates of returns for slipping brake-cables and loose cranks dropped tremendously.

Also with the more common use of carbon components, I'd wouldn't risk not using a torque-wrench.

mark754

I have a Craftsman 1/2" square beam type torque wrench that I use on my car. Does anyone know where I can get an adaptor to go from the 1/2" square head to a 1/4" hex (female) for bike use? Haven't been able to find one. Or do I need to buy a 1/4" wrench?

I just broke off a bolt when tightening my stem to the head tube. Guess I'm stronger than I thought I was How tight do you guys usually tighten these bolts, as well as the ones attaching the bars onto the stem?

San Rensho 

Sears has adapters for any which way you want to go, up or down from 1/2 inch square, but why would you want to go to hex? Also, if its a 1/2 inch drive torque wrench, its probably capable of reading very high torques which means you will have difficulty accurately measuring the relatively small torques needed for a bike.

sngltrackdufus

Don't do that,but if you must reduce drive from .50 to .25(lol) use a .50 to .375 then pop on another reducer from .375 to .25 ....
Get a .25 drive..

bellweatherman

This is going to sound totally contrary to what others have been saying, but I know for an absolute fact that Central Machinery (the exact same company that makes Harbor Freight tools) makes the Sears Craftsman torque wrenches.

mark754

I just realized I have a 3/8" click-type torque wrench, in addition to the 1/2" beam type (it's funny how you accumulate all this stuff you forget about).

Now I need a set of hex socket heads. I'll probably try Harbor Freight - I heard their tools are good and much cheaper than Craftsman. By the way, bikes nowadays all use metric, right? It's a Giant bike.

sngltrackdufus

*nods yes* to the metric

Grand Bois

You can buy 3/8" drive metric hex bits. I got mine at home Depot. They're "Husky" brand and they have the same replacement guarantee as Craftsman tools.

Old Hammer Boy

That does't surprise me one bit. I was the first to mention Harbor Freight in this thread, and was advised to avoid Harbor Freight in lieu of Craftsman. When I bought mine (1/4", 3/8", and 1/2") I first went to Sears, then to Harbor Frt. Both units looked identical and were both made in Taiwan. They seemed to be of equal quality and appeared to be from the same maker to my eyes. Harbor Freight's were about 1/3 the price with the same life-time guarantee. These were the click type wrenches.

Since I don't use a T/R often, I figured it would be prudent to not over pay, but still get something better than the typical Chinese pot metal junk. Most fasteners have a recommended range of tightness, so, when I use it, I set my T/R midway and believe I easily fall within that range. It's better than a by-guess-and by-gollie...

Deanster04

What ever you get remember that you will have this tool for years. Torque wrenches weren't important in the pre carbon days but one little mistake can cost you a whole lot of torque wrenches. Also, remember if you blow it with stainless on Aluminum you can always Helicoil the part.

Al1943

My 1/2" Craftsman beam torque wrench says Made in USA, right on the wrench. But then I've had it a few years, bought it to re-torque the intake manifold on my '69 Mustang Mach I when it was a year old.

Al

mark754

The 1/2" Craftsman beam wrench I bought last year also says Made in the USA.

San Rensho 

Advance Auto has pretty good tool deals. Its not Snap On or Craftsman, but very decent quality and cheap.

Wil Davis

Here's a quote from another thread along similar lines:

"I've bought a lot of stuff from Nashbar over the past few years, and have been mostly happy with their products and their service. However, recently I was looking around for a torque wrench, and they have two available: MM-TORK and MM-TORK4

…somewhat pricey, I thought…

So, imagine my surprise when I searched around The Web, and found this and this !!

The lesson being that although Nashbar are pretty good, you owe it to yourselves to shop around… "

- Wil

mark754

Went to my local Harbor Freight this morning. They have 1/2" click-type torque wrenches for only $12.99. I'm not sure I'd trust the accuracy of one, though their hand tools do have a lifetime guarantee. It looked just like my Proto.

Got a 9-pc set of 3/8" hex sockets for only $16. The closest thing at Sears is $99.

mx_599

i can't wait till this torque wrench thread hits a 3rd page!!!

Psimet2001 

Let me see if I can push it there...

When I wrenched on steel bikes in the 80's and 90's I never used a torque wrench. I did everything by "feel" and consequently stripped out a few fasteners, damadged headsets, pitted bearing races, etc...

Whiel studying Engineering I learned a heck of a lot about fastners, strength of marterials, and machine design. I now work in designing and building heavy industrial hydraulic cylinders (read pressure vessels that are 1 step away from being a bomb). In my line of work if you don't torque to the right spec the assembly can fail and kill someone.

Maybe that's a little too over-dramatic, but you get the point. With ever increasing design capabiities, and reducing safety factors in the name of weight savings it is a good idea to use a TW.

I have 2 TWs within arms reach at ALL times now. They are the Craftsman click-type. I will say from experience that these do not maintain their calibrations over time. Luckily I can take mine into work, buy our lab guy lunch and walk out with re-calibrated TWs. Also TWs are not as accurate at the ends of their operating range (FYI).

A note on Craftsman TWs... They are not considered "Hand-Tools" and do not fall under the standard Craftsman Lifetime Warranty (sold for Sears in high school). They carry a 90 day warranty.

Happy wrenching!