Torque Wrench - Wasted Money?

[Johan Bornman]

Never underestimate the use of a torque wrench when tightening something like an engine head. This is a large flat surface that needs to fit very evenly on the engine block. Only a torque wrench and lubricated bolts can give you enough certaintly that the two surfaces are parallel and compressing the head gasket evently.

The only two places on a bike I can think of where equal torque is required is in the two stem clamp bolts that hold the steerer onto the stem and, the multi-bolt clamp that holds the handlebar onto the stem.

However, once the mechanic is aware of this he can easily do this by feel. Important is to alternate between bolts and tighten each one only a little bit at a time.

Car wheels require this technique as well. If only Speedy Tyre can figure this one out.

 

 

[turtlek]

ok i have a classic example of a so called professional wrench jockey (mechanic) he was working on one of the pro's bikes at his shop and while using a torque wrench he overtightened the pedal into the cranks so much so that the pedal spindle stripped the crank arm threads this was with a torque wrench and it did look like he was using it correctly from me glancing over while he was setting the required torque but it just goes to show nothing is perfect but in this case the wrench jockey was also an idiot

[turtlek]

Never underestimate the use of a torque wrench when tightening something like an engine head. This is a large flat surface that needs to fit very evenly on the engine block. Only a torque wrench and lubricated bolts can give you enough certaintly that the two surfaces are parallel and compressing the head gasket evently.

 

The only two places on a bike I can think of where equal torque is required is in the two stem clamp bolts that hold the steerer onto the stem and' date=' the multi-bolt clamp that holds the handlebar onto the stem.

 

However, once the mechanic is aware of this he can easily do this by feel. Important is to alternate between bolts and tighten each one only a little bit at a time.

 

Car wheels require this technique as well. If only Speedy Tyre can figure this one out.

 

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Johan dont you think even torque would be needed on the bolts on the newer shimano road crank arms?????

[Johan Bornman]

ok i have a classic example of a so called professional wrench jockey (mechanic) he was working on one of the pro's bikes at his shop and while using a torque wrench he overtightened the pedal into the cranks so much so that the pedal spindle stripped the crank arm threads this was with a torque wrench and it did look like he was using it correctly from me glancing over while he was setting the required torque but it just goes to show nothing is perfect but in this case the wrench jockey was also an idiot

 

I once asked the tyre guy at Tiger Wheel to show me how he worked the torque wrench. He demonstrated the callibration nicely, then proceeded to tighten the bold. Once the wrench clicked, he still gave it a good quarter turn just to make sure.

 

It sounds to me like your maccie worked at Tiger Wheel in his previous life.

 

With the right torque, a pedal eye will NOT strip. He duffed, finish and klaar.

 

"Johan dont you think even torque would be needed on the bolts on the newer shimano road crank arms????? "

 

I'm not sure which cranks and bolts you're talking about but assuming you're talking spider bolts, the answer is now. They're not critical in this way.

 

PS - a crank is already an arm. Saying "crank arm" makes my brain hear "arm arm" and my eyes go wonky.

 

 

 

[turtlek]

ya the guy i was talking about is quite an idiot hahaha

 

 

 

and about the crank arm it is the crank bolts that hold the Dura Ace 7800 and ultegra cranks in place

[dirtrider]

In the tyre bay we use something called an Air-tool with a torque shutoff valve . It goes Grrrrrrr and then clack-clack-clack . At this point (clack-clack) you can release the trigger as it will not tighten anymore . As you may all know there will be different setting for steel and alloy rims , that is why you sometime battle to get your flat mag-tyre of after a visit to tyre shop . And yes Johann that is what a toque wrench should be used for , pulling your newly skimmed cylinder head flush to the block . And like you said it also works very nicely on any other stuff where two pieces are held together with more than on bolt/nut and got a gasket in between .