Torque wrench, how critical

[screenman]

Mr Messy, you build cars and I am the PDR guy. I think we agree here on a few points.

One thing though nipped up tight at 25 maybe different from nipped up tight at 75.

 

[mr messy]

Mr Messy, you build cars and I am the PDR guy. I think we agree here on a few points.

One thing though nipped up tight at 25 maybe different from nipped up tight at 75.

Exactly my point. What measurement is a "nip"? Usually find most will overtighten to be on the "safeside" unless its high torque where more likely to see undertightening as people don't appreciate or are able to generate the forces required.

Im a masochistic jigsaw lover screenman hence why i do full stripdowns

 

[Soltydog]

Thanks guys for all the (conflicting) advice
General consensus seems to be better safe than sorry & I have today taken delivery of the Giant torque wrench today

 

[subaqua]

Thanks guys for all the (conflicting) advice
General consensus seems to be better safe than sorry & I have today taken delivery of the Giant torque wrench today

with calibration cert ? otherwise how do you know its correct . just sayin............

 

[smokeysmoo]

If it's the same as MINE then yes they come with a calibration certificate.

 

[john59]

I’ve serviced all my bikes over 31 years without a torque wrench and never had a problem. Saying that I purchased one about four years back and use it all the time now, as more and more components come with recommended torques. It just puts your mind at rest.

John

 

[sddg7tfl]

I've seen three BMW M20 engines (1980's stuff) that had head gasket seepage between cylinders 5 and 6.
The cause every time was some grease-monkey NOT using a torque wrench whilst re-attaching the gearbox
bellhousing (clutch change on two and auto-gearbox change on another).
Basically if the bellhousing bolts are overtorqued the stress pulls the engine block out of shape, and any head
gasket that has seen hundreds of hot/cold cycles isn't going to like this.

Torquing of which, i've also seen two BMW M20 engines that have chomped valve heads because .... the camshaft
pulley retaining bolt wasn't tightened to the correct torque.
Over time the bolt loosens slightly (hot/cold cycles again), causing the pulley to chatter to and fro on the retaining
dowel ... which causes a slot to wear, increasing the "sloppiness" eventually loosing that 0.8mm clearance between
piston and bank balance.

Its torque wrench AND threadlock onto CLEAN threads with me whenever working on engine/gearbox/final drive stuff.

 

[subaqua]

I've seen three BMW M20 engines (1980's stuff) that had head gasket seepage between cylinders 5 and 6.
The cause every time was some grease-monkey NOT using a torque wrench whilst re-attaching the gearbox
bellhousing (clutch change on two and auto-gearbox change on another).
Basically if the bellhousing bolts are overtorqued the stress pulls the engine block out of shape, and any head
gasket that has seen hundreds of hot/cold cycles isn't going to like this.

Torquing of which, i've also seen two BMW M20 engines that have chomped valve heads because .... the camshaft
pulley retaining bolt wasn't tightened to the correct torque.
Over time the bolt loosens slightly (hot/cold cycles again), causing the pulley to chatter to and fro on the retaining
dowel ... which causes a slot to wear, increasing the "sloppiness" eventually loosing that 0.8mm clearance between
piston and bank balance.

Its torque wrench AND threadlock onto CLEAN threads with me whenever working on engine/gearbox/final drive stuff.

them items not bikes though are they.

what did we do before there were printed numbers on items? i know the SR stem ( alloy) on my old raleigh didn't have any torque settings on it and there were not any settings in the manual.

lets hope the torque value is a wet one if using threadlock otherwise it isn't going to be right is it .

 

[black'n'yellow]

Seeing as the thread is alive again, I'll reply..

B&Y, it is not just about being tight enough, but how tight..

To me, 'tight enough' means tight enough to fulfil its purpose. As long as it does that, the specific torque value is irrelevant to me.

I invite you to a competition, you torque 10 bolts by hand and I check each one with a torque wrench. We will put the results up on the forum for all to see.

I've already said that I have no idea of the actual values I am tightening to, so I'm not sure what that would prove. See above. Finally, I have never suggested that anyone should NOT use a torque wrench. I've simply said that I don't, because I don't see the need on a bicycle if you are mechanically adept and/or experienced.

 

[sddg7tfl]

lets hope the torque value is a wet one if using threadlock otherwise it isn't going to be right is it .

Depends on the lubricity of the threadlock.

 

[screenman]

B&Y how do you adapt to the different materials being used on today's bikes. Do you adjust the amount of nip you use on say handle bars and seat posts or do you use the same on both.

 

[black'n'yellow]

B&Y how do you adapt to the different materials being used on today's bikes. Do you adjust the amount of nip you use on say handle bars and seat posts or do you use the same on both.

Not much adaption needed IMO. All my bars and stems have always been aluminium, and they still are. Interestingly enough though, the torque value printed on one of my stems (5nm from memory) does not differentiate between steerer types.

As for seatposts, I have a combination of alu/alu, carbon/alu and carbon/carbon (where one is the seatpost material, the other is the seat tube). In all cases they are retained by a steel bolt pulling on an aluminium collar, in one case with a steel thread insert. And in all cases, I just nip them 'tight enough' to stay still. Ironically, it's impossible for me to describe exactly how much I 'nip them up' because I don't use a torque wrench. But I build and race all my own bikes and have done for 20 years - so far so good.

 

[screenman]

But the pro mechanics use a torque wrench. I wonder why, built and raced my own bikes for 42 years.

I would suggest for most people a small investment in a torque wrench is a good idea.

 

[black'n'yellow]

But the pro mechanics use a torque wrench. I wonder why, built and raced my own bikes for 42 years.

I would suggest for most people a small investment in a torque wrench is a good idea.

If we're talking about cycle mechanics, I know plenty that don't - it comes down to individual preference. Something like a Ritchey torque key would make most sense for people who are not confident enough to tighten without help.

 

[screenman]

A cycle mechanic who does not use one should not be trusted, to do the job properly and to the manufacturers standard that is..