Torque specifications - all parts

[nox1111]

Until recently it was perfectly fine to have a good feeling for a tight screw or locked bolt, but nowadays all manufacturers are providing torque specifications in their service manuals.

 

The correct torque for bolts and parts are such an important thing, (especially when you have a carbon frame or parts)and I have not been able to find a thread about it, that I thought I'd start one.

 

Basics: Over tightening strips and damages, under tightening causes crashes and creaks.

 

Please add any brand specific info that you have, let's get this thread all info'd up for torque.

 

I would recommend picking up a decent torque wrench if you work on your own bike, if not, stress that your LBS working on your bike conform the the manufacturer's torque specs for your parts and or frame.

 

 

Here's the Parktool guidelines in PDF. http://www.parktool....blog/torque.pdf

 

And some Parktool Torque related info: http://www.parktool....ns-and-concepts

Edited September 3, 2014 by nox1111

[droo]

Good idea, think this definitely deserves a sticky. I'll post a few links when I've got time to dig them up.

[Soufflé]

List which I use daily when servicing bikes.

Torque Settings.pdf

[ChUkKy]

Santa Cruz torque specs are suspect at best for the rear shock bolt which bolts onto the linkage.

They say 160in-lb which is 18nm

 

The oke who put that in there must have been a gorilla of sorts, I snapped the bolt at 12nm so in my rage I got looking on MTBR and see im not the only one its happened to.

Its the M8 x 40mm with a 12mm thread length as in the pic.

 

 

Fortunately I got a steel one as a substitute from a mate, it works perfectly and Ive tightened that to 11nm, it has not budged a bit... not as long as I have a hole in my backside is it gonna come out.

18nm... that guy must have been smoking tik

[Raydek]

This is great, started doing my own servicing of late and have been looking for something like this...

 

@Chukky I invested in a torque wrench and seems it needs to be maintained/serviced and also calibrated every now and then, so might not have been the specs that were wrong, maybe the wrench was over tightening..

 

Edit:

Most click wrenches are built with an internal spring mechanism that is compressed to against a lever. Adjustable wrenches use springs that must meet a linear capability test. After use, externally adjustable click wrenches should be turned back to minimum scale value. This helps to preserve the linearity of the spring and calibration of the wrench. All calibrated wrenches should be backed off to the minimum setting when stored.

Edited September 3, 2014 by Raydek

[droo]

Santa Cruz torque specs are suspect at best for the rear shock bolt which bolts onto the linkage.

They say 160in-lb which is 18nm

 

The oke who put that in there must have been a gorilla of sorts, I snapped the bolt at 12nm so in my rage I got looking on MTBR and see im not the only one its happened to.

Its the M8 x 40mm with a 12mm thread length as in the pic.

 

 

Fortunately I got a steel one as a substitute from a mate, it works perfectly and Ive tightened that to 11nm, it has not budged a bit... not as long as I have a hole in my backside is it gonna come out.

18nm... that guy must have been smoking tik

 

I've done that too. And those bolts aren't cheap either.

[JXV]

Tks for the heads up on the SC torque spec. 18Nm is a bit much for M8, especially if not steel. It still helps to have a "feel" for the different sizes. Have sheared a few bolts in my time

[droo]

Tks for the heads up on the SC torque spec. 18Nm is a bit much for M8, especially if not steel. It still helps to have a "feel" for the different sizes. Have sheared a few bolts in my time

 

Titanium, those ones 18 Nm will guarantee you a trip to your LBS for a new pivot bolt kit, since they're not sold seperately. 10 Nm is fine.

[Soufflé]

List which I use daily when servicing bikes.

When buying a torque wrench make sure that it can torque in both directions (clock/anti-clock). You need this when tightening BB's and pedals

Edited September 3, 2014 by veonix

[ChUkKy]

This is great, started doing my own servicing of late and have been looking for something like this...

 

@Chukky I invested in a torque wrench and seems it needs to be maintained/serviced and also calibrated every now and then, so might not have been the specs that were wrong, maybe the wrench was over tightening..

 

Edit:

Most click wrenches are built with an internal spring mechanism that is compressed to against a lever. Adjustable wrenches use springs that must meet a linear capability test. After use, externally adjustable click wrenches should be turned back to minimum scale value. This helps to preserve the linearity of the spring and calibration of the wrench. All calibrated wrenches should be backed off to the minimum setting when stored.

 

I know how to use a torque wrench, not the first time I've used one either. I've used them for putting motors together so I know my way around tools.

 

The bolt snapped when it shouldn't have. Simple as that. Few other instances of it as well

[Raydek]

 

I know how to use a torque wrench, not the first time I've used one either. I've used them for putting motors together so I know my way around tools.

 

The bolt snapped when it shouldn't have. Simple as that. Few other instances of it as well

 

Fair enough.. Was just a thought.

[BenGraham]

This thread couldn't have come at a better time. Currently building my bike and have quite a few new bits to put on this weekend. Very exciting. Just ordered a torque wrench to be safe though but alas its not reversible. Any way around this for tightening BB cups? Maybe someone knows of a clever trick. I think I'll probably torque the non reverse thread side and get a feel for it and then apply the same feel on the reverse side. Hopefully that'll get me close enough. I bought the cheapest torque wrench I could find. Yes some may say you should buy one that will last blah blah but its still a hell of a lot more expensive than no torque wrench which was my original intention.

[Spoke101]

List which I use daily when servicing bikes.

 

This is just IMO

 

In my personal experience, this does not apply to the home mechanic.

 

I am all for torquing bolts where it matters like for super light weight carbon components ie. AX lightness, Schmolke, Forks, Shocks etc.

But stems, shifters, brakes, cranks, pedals, etc I don't have the time and when you do it 100 times a day you get a built in torque wrench in your wrist, It also helps when your strength maxes out at about 40Nm

 

Looking at that PDF, 35Nm for pedal shafts After a few years you will never get that shaft out the crank. I generally use a "T" bar and just wrist tight and have never had a pedal come loose.

 

Also I would like to see someone tighten KCNC stem bolts to there recommended torque 5Nm on a carbon steerer tube even with fiber grip and then go for a ride trough a rock garden. Your bars will end up in the same direction as the wheel and you will have unexpectedly bought some property.

Edited September 3, 2014 by Spoke101