860GT head nut wrench and torque setting

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Craig in France
Cagiva Gran Canyon
Posts: 875
Joined: Tue Mar 23, 2004 3:58 pm
Location: Montpellier, France

Re: 860GT head nut wrench and torque setting

Post by Craig in France »

machten wrote: Yes, that's the chap, Craig.
Ta.
machten wrote:Are your distributor advance springs doing what you think?
Almost definitely not, Kev :) . But on the basis of, "What you don't know can't hurt you", I shall "Let sleeping dogs lie" :lol: Plus the fact the Old Girl starts good and still pulls the ton with breath to spare ...

Fair point about postage costs these days, btw. Postal services the world over have been wacking up their parcel costs up over the last few years, presumably to compensate for the decline in letter post. Sure does affect the amount I'm prepared to pay - so many sellers don't seem to appreciate it's the TOTAL cost that matters.

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Steve Foster
Parallel Twin
Posts: 141
Joined: Thu Dec 07, 2006 2:43 am
Location: Sydney, Australia.

Re: 860GT head nut wrench and torque setting

Post by Steve Foster »

Kev,
In a clicking torque wrench it occurs not on the fulcrum and not at the end, but usually 1/3 to 1/2 way up the lever. So how does that affect tourque readings with a straight lever extension? Steve Foster???
The really important thing to remember is what BevHevSteve pointed out i.e.
Snap in your torque wrench perpendicular to the [extension] wrench and use the factory torque spec.
If the extension is perpendicular to the lever then there is no effective lengthening of the lever and it doesn't affect the output torque. If it is not perpendicular then there will be a component of the extension length which will add to the length of the lever and this will effect the torque, making the scale inaccurate.

And then to confound things there's the whole issue of the effect of friction/lubrication. Specified torque values often assume clean and dry parts - no rust etc, just shiny metal. If the threads are oiled, the torque might need to be reduced by 15-25%.

Steve
1974 Ducati 750 GT

User avatar
Craig in France
Cagiva Gran Canyon
Posts: 875
Joined: Tue Mar 23, 2004 3:58 pm
Location: Montpellier, France

Re: 860GT head nut wrench and torque setting

Post by Craig in France »

Steve Foster wrote: And then to confound things there's the whole issue of the effect of friction/lubrication. Specified torque values often assume clean and dry parts - no rust etc, just shiny metal. If the threads are oiled, the torque might need to be reduced by 15-25%.
A very good point, Steve. Laverda, for example, at the foot of their torque table for the RGS model wrote: "We recommend the application of molybdenum grease on the threads and underside of the nuts".

So mount them dry, and you risk over-torqueing the darlings. And then there's the whole issue of how accurate is your torque wrench? * All in all, I can understand why a few experienced mechanics choose to leave the torque wrench in the drawer ... :) :shock:

Craig

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