100 nm without a torque wrench

[Grahamm]

I've finally got around to replacing the chain and sprockets on my FZ6, but I've hit a little snag...

The Haynes manual says the bolts on the rear sprocket should be tightened to 100nm, but my torque wrench only goes up to 50nm...

So how do I get to 100nm?

[dazza]

Do it twice

[fazerscotty]

100 nm - is that two or three white knuckles? 
(Buy a bigger torque wrench!)

[BBROWN1664]

1m long spanner with you stood on the end assuming you weigh 100kg will work.

[pilninggas]

1m long spanner with you stood on the end assuming you weigh 100kg will work.

that would be way too much torque; 100kgf = 980Newtons (x1metre) = 980Nm of torque

I have an 18" norbar torque wrench and it's pretty much that with my full applied arm effort (weedy southern nancy)

[sadlonelygit]

seriously now, they're 8 or 10mm thread, just lean on them. common sense will tell you if they're tight.

[darrsi]

Wrench it until you fart.
If you shit yourself it's too tight. 

[Grahamm]

that would be way too much torque; 100kgf = 980Newtons (x1metre) = 980Nm of torque

I have an 18" norbar torque wrench and it's pretty much that with my full applied arm effort (weedy southern nancy)

Ah, now *that's* a useful reply

It's been a very long since I did physics, but you've reminded me how to figure it out.

I've got a socket wrench which is about 20cm long, so if I needed to apply 10kg on a 1m wrench then that would be 50kg on a 20cm wrench, ie pushing down with most of my weight would do it.

Thanks!

[pilninggas]

that would be way too much torque; 100kgf = 980Newtons (x1metre) = 980Nm of torque

I have an 18" norbar torque wrench and it's pretty much that with my full applied arm effort (weedy southern nancy)

Ah, now *that's* a useful reply

It's been a very long since I did physics, but you've reminded me how to figure it out.

I've got a socket wrench which is about 20cm long, so if I needed to apply 10kg on a 1m wrench then that would be 50kg on a 20cm wrench, ie pushing down with most of my weight would do it.

Thanks!

Cheers,

That suits me; I'm a Design&Tech teacher and in september i'm also teaching science, so at least i'm explaining things correctly.....

[lew600fazer]

Good rule of thumb finger tight then one flat on the nut and for extra security apply a touch of Loctite Blue before assembly.

[darrsi]

Good rule of thumb finger tight then one flat on the nut and for extra security apply a touch of Loctite Blue before assembly.

You are obviously joking for 100Nm?
Unless you have fingers like "The Thing" from The Fantastic Four?

[lew600fazer]

Good rule of thumb finger tight then one flat on the nut and for extra security apply a touch of Loctite Blue before assembly.

You are obviously joking for 100Nm?
Unless you have fingers like "The Thing" from The Fantastic Four?

seriously now, they're 8 or 10mm thread, just lean on them. common sense will tell you if they're tight. (from someone else on here)

The rear axle nut is 150nm , I don't have a torque wrench that goes to 150nm so all I have done with that is mark the flat of the nut and the area next to the nut, Back it off do what I need to do and tighten it back to were it was. All I am using is a split ring spanner no bars or anything else and I am not popping a vein to slacken/tighten the nut. Now perhaps it has not been torqued up to the correct torque in the first place , but guess what the wheel has never come off or come lose on me yet. All I am doing from finger tight is turning the nut through 1.5 flats
After spending my working life as an engineer I reckon I would have a pretty good idea when a nut is tight.

So how many flats do you reckon from finger tight on a 8-10mm bolt/nut do you reckon you would need to turn it to achieve 100 nm?

[darrsi]

Good rule of thumb finger tight then one flat on the nut and for extra security apply a touch of Loctite Blue before assembly.

You are obviously joking for 100Nm?
Unless you have fingers like "The Thing" from The Fantastic Four?

seriously now, they're 8 or 10mm thread, just lean on them. common sense will tell you if they're tight. (from someone else on here)

The rear axle nut is 150nm , I don't have a torque wrench that goes to 150nm so all I have done with that is mark the flat of the nut and the area next to the nut, Back it off do what I need to do and tighten it back to were it was. All I am using is a split ring spanner no bars or anything else and I am not popping a vein to slacken/tighten the nut. Now perhaps it has not been torqued up to the correct torque in the first place , but guess what the wheel has never come off or come lose on me yet. All I am doing from finger tight is turning the nut through 1.5 flats
After spending my working life as an engineer I reckon I would have a pretty good idea when a nut is tight.

So how many flats do you reckon from finger tight on a 8-10mm bolt/nut do you reckon you would need to turn it to achieve 100 nm?

If i get a sporting chance i'll give it a try at work and let you know.
Common sense always prevails, but it's probably the lower settings where people really get it wrong, like exhaust header nuts(12Nm), caliper pad pins(10Nm), etc.
Even worse if using copper grease, where even i have become a victim of foccing up my own rear caliper, using a torque wrench.

[lew600fazer]

Good rule of thumb finger tight then one flat on the nut and for extra security apply a touch of Loctite Blue before assembly.

You are obviously joking for 100Nm?
Unless you have fingers like "The Thing" from The Fantastic Four?

seriously now, they're 8 or 10mm thread, just lean on them. common sense will tell you if they're tight. (from someone else on here)

The rear axle nut is 150nm , I don't have a torque wrench that goes to 150nm so all I have done with that is mark the flat of the nut and the area next to the nut, Back it off do what I need to do and tighten it back to were it was. All I am using is a split ring spanner no bars or anything else and I am not popping a vein to slacken/tighten the nut. Now perhaps it has not been torqued up to the correct torque in the first place , but guess what the wheel has never come off or come lose on me yet. All I am doing from finger tight is turning the nut through 1.5 flats
After spending my working life as an engineer I reckon I would have a pretty good idea when a nut is tight.

So how many flats do you reckon from finger tight on a 8-10mm bolt/nut do you reckon you would need to turn it to achieve 100 nm?

If i get a sporting chance i'll give it a try at work and let you know.
Common sense always prevails, but it's probably the lower settings where people really get it wrong, like exhaust header nuts(12Nm), caliper pad pins(10Nm), etc.
Even worse if using copper grease, where even i have become a victim of foccing up my own rear caliper, using a torque wrench.

Cheers Darrsi, maybe my old grey cells are not what they used to be , my son told me last night that he thinks I am starting with Alzimers as I keep asking him stupid questions.
I spent my time a s a marine engineer on a lot of nuts, studs bolts etc! we would use hydraulic stretching gear on the stud and then just follow the nut up by hand and release the hydraulic pressure , pretty sure this is not just the domain of the marine industry. Other methods was a hot poker down the centre of a stud heat it up fit the nut and tap round with a skeleton spanner one flat and remove the hot poker as the stud cooled you got the correct torque setting.

[darrsi]

The thing is just a small movement of a flat can be a huge difference in torque, especially with the higher numbers, so it is still quite random doing it that way.

[chaz]

Are you sure it's 100 nms seems a lot, you do mean the bolts that hold the sprocket to the hub?
A 100nms coverts to 73.76  foot pounds, using a 1/2 drive standard ratchet wrench the most you can get without swinging on it is around 75 foot pounds, ok some will get more but the fitter who told me set up a bolt in a vice and I was within a couple of pounds of it, so it's ok as a guide.
I took my rear sprocket off to paint a few months ago and didn't tighten them up that tight but I did use thread lock.

[sadlonelygit]

and shouldn't sprocket nuts be nylocs anyhoo?

[Dave48]

Are you sure it's 100 nms seems a lot, you do mean the bolts that hold the sprocket to the hub?
A 100nms coverts to 73.76  foot pounds, using a 1/2 drive standard ratchet wrench the most you can get without swinging on it is around 75 foot pounds, ok some will get more but the fitter who told me set up a bolt in a vice and I was within a couple of pounds of it, so it's ok as a guide.
I took my rear sprocket off to paint a few months ago and didn't tighten them up that tight but I did use thread lock.

+1!
Are you SURE that the sprocket retaining bolts should be tightened that amount. Dont have my Fazer workshop manual any more since I sold bike but what are they 6mm or 8mm diameter?
Certainly the rear axle needs a high torque setting something over 100NM from memory but surely not the sprocket bolts? Just recheck book to be on safe side & as already suggested use a dab of blue loctite on the threads.

[Grahamm]

Are you sure it's 100 nms seems a lot, you do mean the bolts that hold the sprocket to the hub?

That's exactly what it says in the Haynes Manual:

Rear sprocket nuts: 100 Nm
Rear wheel axle nut: 120 Nm

I'm going to use Threadlock as well anyway.

[J_Dub]

100 Nm is correct, (boxeye is 60Nm) for the sprocket. Buy a torque wrench you need one to tighten the spindle too!

[lew600fazer]

100 Nm is correct, (boxeye is 60Nm) for the sprocket. Buy a torque wrench you need one to tighten the spindle too!
[/quote


Just had to add, I am a by the book kind of person, I read all the posts stating not to follow the manufacturers specs and I have successfully stripped the threads of one of my studs by torquing to 100NM/72lbft as stated in the manuals. It was a last minute sprocket change due to a manufacturers fault just before my planned trip which I have had to delay a few days. From now on I am going to use 38lbft! Wish someone bet me a beer, I need one!
[/size]
[/size]Found this on another forum, I think I would air on the side of caution, you may get away with it on nut bolts&Nuts, do not forget when you tighten and slacken then tighten again nuts & bolts some of the elsatisity is lost in the materails.

[JoeRock]

Are you sure it's 100 nms seems a lot, you do mean the bolts that hold the sprocket to the hub?

That's exactly what it says in the Haynes Manual:

Rear sprocket nuts: 100 Nm
Rear wheel axle nut: 120 Nm

I'm going to use Threadlock as well anyway.

Personally I wouldn't bother - get them torqued up properly and you shouldn't need it (pretty sure they're meant to be dry threads on those nuts according to the Yam manual?)

[chaz]

well I better get me nuts tightened?
How can you torque them up dry and have thread lock on? I've never used thread lock as a lube but it must have some effect on it.

[lew600fazer]

As someone else mentioned are they not nylock nuts anyway??
For me the only bolts , nuts , studs I would likely use a torque wrench on would be , bottom ends, main bearings and cylinder head nuts, coming from an engineering background I would think I am reasonably confident to not over torque or under torque fastenings.

[VNA - BMW Wank]

If you have torque wrenches it makes sense to use them.

Can't remember what the torque for my rear axle nut is, but considering I like to be able to get it back off I tend to torque it a good wee bit short. 

I'm not keen on cheap torque wrenches. 

Somebody mentioned Norbar.  I recently bought a Norbar, very nice, comes with a calibration certificate.  Not cheap but will last the home mechanic a life time.  Also got a Britool which is nice too.

Did buy a cheap (ish) Williams wrench a while back.   Used it a couple of times but I'd no confidence in it.  Replaced with the Norbar.