Bicycle Mechanics - People spend so much on the fancy gizmos for their bikes why don't they...

buy a torque wrench?

I'm curious because it's frightening to me to think thousands of bike owners out there just crank away on the wrenches and allen keys with no guage.

I spent more than 2k on my ride and the best $60 so far has been the Sears Microtorque I bought to make sure I didn't damage the frame, stem, etc.

Weigh in please.

Pj

I do not have the time to tinker with my bike..Have a great wrench...But, it is not as simple as Hand tight? If not, guess your $60 gizmo is worth it..

I found torque more critical back in the 70's; when I had the motorcycle. It was too easy to strip threads in those castings. (Japanese motorcycles) I still have it ---- Challenge beam torque wrench. 0-150lbs.

I just got the Park TW-1 and 2 a few weeks back and, even though I don't use them much, I really like knowing that they're available to me 'just in case'. I've screwed up plenty of things before I got 'em.

buy a torque wrench?

I'm curious because it's frightening to me to think thousands of bike owners out there just crank away on the wrenches and allen keys with no guage.

I spent more than 2k on my ride and the best $60 so far has been the Sears Microtorque I bought to make sure I didn't damage the frame, stem, etc.

Weigh in please.

PjIt's not an issue if you know what you are doing. The inept and mechanically bankrupt will bugger stuff even with a torque wrench!

I answered yes to the poll question, but I do not use a "torque wrench". Over time one gets an excellent feel for the amount of torque needed for each application.


Also, one should understand that a torque wrench reading can be very misleading to what is really going on. All it measures is the torque applied to the fastener. It does not measure the amount of force applied to the other side of the fastener which in the worse case could be zero. Non-lubricated threads can have friction coefficients 2-5 times higher than lubricated threads. There's variation amongst lub's. Dirty threads are worse. There's also the friction underneath the fastener - like the bearing surface under the nut. Etc. Etc. For most industrial applications I find the best method is a very sensitive feel for the wrench. Also for torque critical situations a recheck after some use can be important especially with new threads - fastener creep can be 20-30%. Particularly true with new spokes and nipples.

A torque wrench is a very good investment, if it saves you one time it pays for itself!

Torque wrench? Bah!

Tighten till you feel it start to strip, then back off a half turn :p

buy a torque wrench?

I'm curious because it's frightening to me to think thousands of bike owners out there just crank away on the wrenches and allen keys with no guage.

I spent more than 2k on my ride and the best $60 so far has been the Sears Microtorque I bought to make sure I didn't damage the frame, stem, etc.

Weigh in please.

Pj

Don't be frightened.
If I ever use a LBS for service, I'd prefer he'd use common sense rather than a torque wrench.

Torque wrench? Bah!

Tighten till you feel it start to strip, then back off a half turn :p

Yep, that's pretty much my method..... doing it for many years.

The only time I use my 30 year old Craftsman torque wrench is when I'm tightening crank bolts (bicycle) and head bolts (car).

"Tighten till you feel it start to strip, then back off a half turn "

Problem is that with carbon a bit too far is costly, very costly.
Tighten your stem a bit too much and say good bye to your all carbon fork.

"Tighten till you feel it start to strip, then back off a half turn "

Problem is that with carbon a bit too far is costly, very costly.
Tighten your stem a bit too much and say good bye to your all carbon fork.

I was told by a very experienced pro that to tighten up carbon stems (to handlebars and forks) without a torque wrench is really pretty dumb. You might get by without it, but you're taking a pretty big chance.

i have never used a torque wrench on my bicycle, i think i have one somewhere in the garage i use every now and then for the car, I have not seen it forever. I dont think its necessary, i have not once cracked or damaged anything, i guess you just use common sense.

I was told by a very experienced pro that to tighten up carbon stems (to handlebars and forks) without a torque wrench is really pretty dumb. You might get by without it, but you're taking a pretty big chance.

Yes I agree. If they dont get tightened enough, the screws will loosen, but too tight and the CF will crack. A guy at the my LBS had his CF bar crack on him. Costly mistake.

Yes I agree. If they dont get tightened enough, the screws will loosen, but too tight and the CF will crack. A guy at the my LBS had his CF bar crack on him. Costly mistake.

Not to mention that if your stem, handlebars, or steering fails when you are bombing down a steep hill you are in deep barnyard waste.

and just to make matters worse torque wrenches do need to be calibrated once in a while
(mine gets done annually)

It's not an issue if you know what you are doing. The inept and mechanically bankrupt will bugger stuff even with a torque wrench!

The second part is certainly true.

Oh, and don't wear a helmet either.

Torque wrench no good without torque specs for any given fastener.

Most of the Shimano stuff gives torque specifications on the installation instructions. Moreover, for current products, these can be found on-line at the Shimano website.

That said, I agree with Sydney. I have never used a Tourque wrench and have built and serviced many bikes without problems. "Gently with feeling" and knowing when to stand on the end of a 6ft extension bar are important skills :)

Cheers,

Ed

Most of the Shimano stuff gives torque specifications on the installation instructions. Moreover, for current products, these can be found on-line at the Shimano website.


True and no argument about Shimano and some others. But not all. And the places where a torque wrench cannot be useful are quick releases, particularly on seat posts, but also on carbon forks, and adjusting cones on hubs and cups on non-cartridge BBs. Sometimes items are supplied without any instructions whatsoever.

I do agree that gentle tension using pressure on fingers and palms is an acquired talent. A motor mechanic acquaintance would use a torque wrench only for cylinder head bolts or studs. But then, he worked on cars day in, day out.

I can't imagine a bike shop condoning the time wasted adjusting a torque wrench, and checking every single nut and bolt in servicing bikes... some CF components excepted.

The answers have been enlightening to say the least.

I find some of the humorous ones the best...such as tighten till it feels like it's stripping and back off a half turn- Killer. That's how I used to wrench on everything...of course I was 12 years old then.

I agree that an LBS using a wrench on every threaded part is overkill. But Sydney's (and a few others) idea that "knowing what you're doing" isn't the best practical advice. I do agree with Syd that a complete moron will screw it up even with a torque wrench.

PJ

I agree that an LBS using a wrench on every threaded part is overkill. But Sydney's (and a few others) idea that "knowing what you're doing" isn't the best practical advice. I do agree with Syd that a complete moron will screw it up even with a torque wrench.

PJ

The problem with the "knowing what you're doing" techniques is that the morons *think* they know what they're doing.

Oh, and I know what I'm doing. :p :lol:


I would use a torque wrench for carbon bits, but as I don't currently have any, I don't have a torque wrench.

I use one for head bolts, intake manifolds, crank and piston bearing caps. I don't use it on my bike. But, I will say this. I have turned wrenches (not professionally) all of my life. There are things that need to be torqued to a very specific range. There are just none on my bikes that an experienced touch won't do.

The last bolt that I stripped was a valve cover bolt on a 1974 Chevy Vega. 25 years ago. Why do I remember that??? I work on my own cars, and I repair vintage watches (talk about needing to control your torque).

I agree, if you are not totally comfortable mechanically, you should use one.

I am in the process of swapping out my Shimano 105 cranks for FSA Carbons. I just got a torque wrench and will use it often for repairs. I remember when I first replaced my seat post (the one that come with the bike was a tad too short, so I swapped out my old beater bike post), It has a smaller diameter and I really ratched it down to keep it from slipping. When I visted the bike shop the guy told me to get the right diameter post and don't over tighten it or I could crack my carbon frame. I have since found a nice Specialized Carbon seat post and did not over tighten it (just snugged it). Now that I have a torque wrench I can verify its tightness is correct. Good thread!

Here's the equation I use to calculate the force generated by a particular torque.

A mess, huh?

Or, you can use T = 0.20Fd if no one's watching!

Torque is very important if you have a fastener subject to a fatigue load, like the ones that hold on your motor heads. For bikes, no. Never used a torque wrench.

OK, now why won't my attachment display?

I use my torque wrench on carbon bits only. I figure I can guess at the steel/aluminum parts easily enough.

Torque wrench? Bah!

Tighten till you feel it start to strip, then back off a half turn :p

LOL, that's like that seinfeld joke about medication.
"Doc, give me the maximum allowable human dosage, find out what will kill me.. then back it off a notch."

Back on topic, if you have a slipping torque wrench, make sure you return it to zero torque after using it otherwise it'll wear out the mechanism.

It's not an issue if you know what you are doing. The inept and mechanically bankrupt will bugger stuff even with a torque wrench!

It is an issue, even if you know what you are doing. We have a custom dual crown DH fork on our tandem. Overtighten the clamps, and you'll either break the lower crown, or crush the tubing, which will cause your fork to bind. You cannot just snug it up to "What feels right". As this is a bike that cost in the neighborhood of AU$10k to build, we don't mess around. Stems, cranks, disc brakes and rotors - they are all tightened to factory spec. Woudl you put your wife on the back of a bike that does an easy 60km/h, and tighten things up by feel? I hope not.

One thing thats missing in this fancy world of socket sets & multi tools is the concept of using the appropriate tool for the job. When the conversation turns to torque, this refers to leverage. A set of wrenches come in progressively larger sizes, as the size of the fasten for which they're intended increases. This has a couple benefits. 1) often smaller fasteners are in smaller spaces - the smaller wrenches fit better. 2) It becomes more difficult to over-torque fasteners. For instance, its tough to apply 100 ft-lb of torque using a 1/4" wrench. The wrench is about 4 inches long, which means you have to apply over 300 lbs of pressure to the end of that wrench - a task unsuited to most humans' hands. However, put a 1/4" socket on the end of a 10" long ratchet and you only have to apply about 80 lbs of pressure to that tool. Consider that it might take only 10 or 20 ft lbs to overtorque the fastener and you start to get the idea. If you're using tools that are more 'one size fits all' you have to maintain a better awareness of the limitations of the parts on which you're working.