to torque or not to torque

thumpjump wrote:

cryptomundo wrote:

...i was worried about trying to use it with lower lbs so thats why i decided to post my question.

Usually torque wrenches are most inaccurate at the extremes of their range. You also get what you pay for when it comes to torque wrenches. I can't imagine torquing something to 5lbs, it would be very loose, almost finger tight at that point.

20lbs a magic number....I can't really say that, it's just what I do. The pinch bolts for the forks are less than that, I believe, and those are kind of important ones, IMO. However, I have 2 torque wrenches and neither of them go below 20, that's why I just snug up to 20lbs:)

alot of computer stuff is torqued to the mm/g

On all of my repairs I find using a torque is essential for a uniform job. With that said I am reluctant to use a my inch pound / newton meter (nm) torque wrench for anything under about 10 inch lbs. or the corresponding nm torque. Oil pan, side covers, clutches, tripple tree, axles etc........ get tensioned according to manufacture specs. Torque & Locktite Blue seems to work hand in hand very well.

As always....Ride safely and have a great time.

It's a good habit to set them to 'zero' when your done.

Ideally, every fastener should be torqued to the proper value. Having something over-torqued can cause just as many problems as having something torqued too little.

With enough experience, and on materials that are more resilient like steel, you may decide that you can get an acceptably accurate amount of torque on something through “feel”. The best way to properly learn that feel, is to use a beam type torque wrench and practice bringing something up to torque while reading the deflection on the gauge. This is a good skill to have, as while riding you rarely have access to a torque wrench and your only gauge to the amount of force you are using is feel. Practice putting on a wheel nut by feel, and then check it with a beam torque gauge. When the nut starts to move, that's how much torque you put on by feel.

All of that is useless if you don't know how much torque you need. That's where the service manual comes in, as it will include torque values for all critical components. If it's not included, you can google “standard torque values” for the type of fastener you are using.

On softer materials where the risk of causing damage by over-torquing is greater or on anything with a gasket or seal, you may decide that your sense of “feel” is not precise enough. For those jobs, I suggest using a torque wrench every time, but again it all depends on what you're comfortable with. It's your bike, and you have to live with the consequences.

Note: My opinion is biased. I work on high performance aerobatic jet aircraft for a living, which demands a level of precision higher then what you may feel required on your bike. On the aircraft, if the procedure states a torque value, it's torqued with a calibrated torque wrench. Every time.

Sort of an old thread I know but I have seen a few comments from people snapping the oil cover bolts while using torque wrenches. I would assume that all the torque values are determined with dry threads. When you are reinstalling the oil cover bolts they are likely covered with oil as well as the holes the bolts are going into. If you try to torque this with a wrench you will go too far due to the oil lubricating the threads. This puts the little bolt under too much tension and Pop!
Loctite also lubricates threads. Anytime I use a torque wrench on something I try to clean the bolt threads as well as possible.

That is my theory anyway. Anyone see a hole in that logic?

Personally, I believe a torque wrench is not necessary for things like the oil filter cover, and will cause more grief than anything else.
7 ft/lbs ain't much.

I would agree .. the drain plug maybe but the oil filter cover i would say no

Subaru297 wrote:

Sort of an old thread I know but I have seen a few comments from people snapping the oil cover bolts while using torque wrenches.

I wonder how many have snapped them without a torque wrench versus those who have done it WITH a torque wrench?

And then I wonder how many of those who were using a torque wrench, used one at the very bottom of it's adjustment, where the +/- error is significant enough to get you in trouble?

Or the $15 bargain torque wrench they got from some Ebay vendor? Have you seen the ridiculous price you pay for a Snap-On wrench that does exactly the same thing?

Or the 30 year old one that's been banging around in somebody's tool box for 20 years and never, ever turned down after being used.

Calibrated? What's that?

And once things screw up after any - or a combination - of the above, the general first reaction is to blame the stupid torque wrench.

The more you're on the tools, the more I think you can fudge it not using a torque wrench. I do very little wrenching, so torque wrenches are my friends. I have good ones, my brother checks their calibration for me occasionally, and that keeps me safe. I'll save the guessing for the trail repairs when necessary, err on the side of caution, and hope the blue Locktite keeps it together if I guess wrong.

My guess is that there is a good reason mechanical engineers supply torque values for fasteners on machinery rather than the phrase "just snug 'er up".

Subaru297 wrote:

Sort of an old thread I know but I have seen a few comments from people snapping the oil cover bolts while using torque wrenches. I would assume that all the torque values are determined with dry threads. When you are reinstalling the oil cover bolts they are likely covered with oil as well as the holes the bolts are going into. If you try to torque this with a wrench you will go too far due to the oil lubricating the threads. This puts the little bolt under too much tension and Pop!
Loctite also lubricates threads. Anytime I use a torque wrench on something I try to clean the bolt threads as well as possible.

That is my theory anyway. Anyone see a hole in that logic?

No holes! That is standard automotive procedure. I learned that as a kid and I'm nearing retirement age now. I have three torque wrenches and will probably buy another. When I torque the very small fasteners I always dial in a little less than the stated value.

Subaru297 wrote:

Sort of an old thread I know but I have seen a few comments from people snapping the oil cover bolts while using torque wrenches. I would assume that all the torque values are determined with dry threads. When you are reinstalling the oil cover bolts they are likely covered with oil as well as the holes the bolts are going into. If you try to torque this with a wrench you will go too far due to the oil lubricating the threads. This puts the little bolt under too much tension and Pop!
Loctite also lubricates threads. Anytime I use a torque wrench on something I try to clean the bolt threads as well as possible.

That is my theory anyway. Anyone see a hole in that logic?

As long as the threads are clean and true, lubricant will not have an affect on the proper torque required.
The proper amount of torque is determined by the fastener req'd and/or used.
A threaded fastener will hold something together with an elastic force, pulling the parts together.
The amount of force a fastener can, properly, provide...is determined in its make up/size, which is why you want the right fastener for the job.
Therefore...when the threads finally bind, hopefully for the right reason, the fastener begins to stretch.
Regardless of material, its this stretching/elasticity that holds things together.
The most accurate way to measure the "torque" of a fastener, is to measure how much it stretches...because we want its best working limit, while not exceeding it.
If you exceed the tensile limit ...it will/should, pull apart.
If you don't stretch it enough...it will not fasten properly.
Because measuring stretch is limited to "studs" or special tools...we approximate, quite accurately, by measuring force applied to a lever...
Like a torque wrench.
Some fasteners are re-usable and some are not, depends on the materials and applications involved.
Hope that helps

Quote :

No holes! That is standard automotive procedure. I learned that as a kid and I'm nearing retirement age now. I have three torque wrenches and will probably buy another. When I torque the very small fasteners I always dial in a little less than the stated value.

Hummm, just dug out (well clicked on and opened, thanks SheWolf!!!! ) the WR manual to tighten the engine cradle bolts today after I loosened them to put on my B&B Bashplate. And I blue locktited the front bolts holding it in place too.

Afta bout 35+ years of wrenching on cars and trucks I've come to the conclusion that things work and last best when torqued to specs. Especially so for things that are a bitch to replace when they fail (or leak) due to incorrect torque specs. Rework sucks.

I torque everything on the bike to spec due to a general lack of bike wrenching experience and the belief that the mfr knows how to make it stay together for it's intended use of bouncing around in the dirt.

Torque wrenches, however, if I were buying again (or buy again) it will be Snap-on. I had a collar break on a Craftsman 1/2" wrench recently which confirmed that just about everything Craftsman has turned into junk.

"As long as the threads are clean and true, lubricant will not have an affect on the proper torque required."

Sorry, that's wrong. A good portion of the applied torque is used to overcome the friction between the threads on the respective mating surfaces. This torque value is predicated on clean, dry threads. This friction is taken into account in a manufacturer's specifications. Any lube will remove this friction value and result in over-torquing. If there is any deviation from a manufacturer's instructions, you're on your own!

Good point about bolt stretch, however. I remember, years ago, when Ford used specify bolt stretch instead of a torque value on certain high-performance engines. This applied to big-end con-rod bolts. It's hard to measure in blind holes, though.

Then I stand corrected.