Torque wrench fooked?

[Marknz]

Just put the bike back together ready for Round 5, and was advised to use 25NM on the torque wrench to tighten up the triple clamps on to the forks. But, I'm wondering if my torque wrench has failed... I was fair hanging off that damn thing and it still didn't 'release' itself. Clearly with it being lightweight alloys and all that, I don't want to feck the bolt and clamps a week out from my first meeting, so here is a 'how long is a piece of string' question for you...

just how much effort should I be putting in to get 25NM out of a modern torque wrench?

Or should I nip them up for now, get them to the track next friday and ask to borrow a reliable torque wrench from someone?

I've seen the result of a first corner handful of brakes with triple clamps not tightened up correctly... it wasn't pretty and I don't want to do it!

Any advice grately received.

Cheers

[mossy1200]

Just put the bike back together ready for Round 5, and was advised to use 25NM on the torque wrench to tighten up the triple clamps on to the forks. But, I'm wondering if my torque wrench has failed... I was fair hanging off that damn thing and it still didn't 'release' itself. Clearly with it being lightweight alloys and all that, I don't want to feck the bolt and clamps a week out from my first meeting, so here is a 'how long is a piece of string' question for you...

just how much effort should I be putting in to get 25NM out of a modern torque wrench?

Or should I nip them up for now, get them to the track next friday and ask to borrow a reliable torque wrench from someone?

I've seen the result of a first corner handful of brakes with triple clamps not tightened up correctly... it wasn't pretty and I don't want to do it!

Any advice grately received.

Cheers

If your in Welly on the weekend you can borrow mine and give it back at round 5. PM me

[SixPackBack]

Mark, if you have a good feel for the appropriate torque on a given fastener using a torque wrench is not always that necessary. Often the most important reason for using a torque wrench is uniformity of torque particularly when in restricted space.

A few years ago I organised my Engineering staff to conduct a series of experiments with various fasteners. The guys were asked to torque the various fasteners up to where they thought appropriate, all the torque values were checked and found to be very close to required values.

The disclaimer I guess is that the experiment was conducted with Tradesman, if you are handy with a spanner-trust yourself.

[Pedrostt500]

The thing with torque wrenches, is you work your way up to a torque setting, so if the recomended torque setting is 20nm then you would set your torque wrench to say 5nm do up all your bolts, if for example a head then to the recomended tightening sequince, then re set the TW to 10 nm and go through the sequince again, then again at 15nm, then finish off at 20nm.
happy to loan you my torque wrench, PM me.

[bogan]

Just put the bike back together ready for Round 5, and was advised to use 25NM on the torque wrench to tighten up the triple clamps on to the forks. But, I'm wondering if my torque wrench has failed... I was fair hanging off that damn thing and it still didn't 'release' itself. Clearly with it being lightweight alloys and all that, I don't want to feck the bolt and clamps a week out from my first meeting, so here is a 'how long is a piece of string' question for you...

just how much effort should I be putting in to get 25NM out of a modern torque wrench?

Or should I nip them up for now, get them to the track next friday and ask to borrow a reliable torque wrench from someone?

I've seen the result of a first corner handful of brakes with triple clamps not tightened up correctly... it wasn't pretty and I don't want to do it!

Any advice grately received.

Cheers

25NM is equivalent to 2.5kg on a meter bar, or on a 350mm torque wrench, about 7.3kg of force on the end. We used one once that you could barely detect when it released itself, was only a real little click, so went to town on some head bolts!

[paddy]

Just how much effort should I be putting in to get 25NM out of a modern torque wrench?

If you hand were positioned 1 foot from the centre of rotation of the wrench then you should need to apply close enough to 8.5 kilograms of "force" (not quite the correct use of the word force but hopefully it will give you an idea).

It would be a bit mickey mouse but you could fill a bucket with 8.5 litres of water and hang it off your wrench 12 inches from the head. When the bolt stopped turning you would be close enough to 25 NM.

[paddy]

Opppsss...toooo slow. :-)

[Marknz]

Thanks for the feedback guys, appreciatte it!

I'm off to see Mossy tomorrow to borrow his, all should be good again soon.

Cheers

[k14]

Yeah 25NM is pretty a pretty light pull of the wrench (unless you are using a tiny 1/4" drive one). I need to start to use a bit of force around 60NM on mine, although it is quite a decent 1/2" drive one.

[Marknz]

Sorted. Many thanks to Mossy for the loan of his TW, and to the other posters for their input. That increasing the load by 5NM per load and rotating through... far too logical for mine, but it works!

And yea, the issue with my TW... mmm, let's just call it 'operator error' for now shall we.

Thankfully the bolts still look good and there was no stripping of threads. That could have been a bloody expensive exercise. And of course now that I have a real idea of what 25NM is, i'll likely never need a TW again.

Cheers
Mark

[Shaun]

sorted. Many thanks to mossy for the loan of his tw, and to the other posters for their input. That increasing the load by 5nm per load and rotating through... Far too logical for mine, but it works!

And yea, the issue with my tw... Mmm, let's just call it 'operator error' for now shall we.

Thankfully the bolts still look good and there was no stripping of threads. That could have been a bloody expensive exercise. And of course now that i have a real idea of what 25nm is, i'll likely never need a tw again.

Cheers
mark

always use one on those bolts mark!!!!