LBS and Torque Wrench

[winjim]

From torque wrenches to Mini Metros

And all in the space of only 2½ years.

 

[Ajax Bay]

all in the space of only 2½ years.

Yes: after the Lazarus rousing of the thread I thought people were desparate to torque during lock down. But clearly motor cars were more on people's minds. I know mine is flashing all sorts of lights at me, saying 'take me for a long, hot engine/exhausting drive, please'!

 

[randynewmanscat]

Yes: after the Lazarus rousing of the thread I thought people were desparate to torque during lock down. But clearly motor cars were more on people's minds. I know mine is flashing all sorts of lights at me, saying 'take me for a long, hot engine/exhausting drive, please'!

I'm pretty sure I was responsible for the resurrection, my mention of Ernest Saunders in another thread may have contributed or the mere business of surfing the site while suffering from cabin fever, probably the latter.

 

[Ajax Bay]

Is Ernie still suffering from court-fright or is he fit and well? Surely Old Father Time welcomed him long ago.

 

[randynewmanscat]

Is Ernie still suffering from court-fright or is he fit and well? Surely Old Father Time welcomed him long ago.

No, he's alive and kicking and has revised history and court transcripts to say that he never claimed to have any degenerative brain disease. I'm pretty sure I read that co defendant Gerald Ronson gave old Ernie the idea for the Alzheimer plea.

 

[Lookrider]

There is also a difference between ‘wet’ torque values and ‘dry’ torque values. If any given bolt is lubricated prior to having a particular torque applied, it will be considerably tighter than the same bolt torqued ‘dry’. Most torque values assume ‘dry’ torque loading.

In layman's terms for instunce
If a value is 5nm
Should you torque a "wet' bolt to say 4.5nm
Thank

 

[Colin Grigson]

In layman's terms for instunce
If a value is 5nm
Should you torque a "wet' bolt to say 4.5nm
Thank

In principle yes, but I recall it’s usual for a torque value to be given as a ‘wet torque’ value when the thread to be torqued must be lubricated. My aeronautical engineering studies were a very long time ago now, hopefully somebody more up to date and knowledgeable will be along shortly.

 

[rogerzilla]

Car engine bolts, with few exceptions, are supposed to be fitted dry and the torque values assume that. Bike manufacturers rarely tell you how they arrived at their torque figures but few bike bolts would ever be fitted dry, because they're not going to live their life in a corrosion-free oil bath.

The other big factor affecting torque, besides lubrication, is whether the threads have been previously used and tightened. Brand new threads will rarely give as high a clamping force as used, smoothed ones. Likewise, gritty and contaminated threads will give a lower clamping force for any particular torque.

If you have a torque range specified like 30-50 Nm, you might want to shoot for the 30 Nm with a used, clean and greased bolt.

If you use titanium bolts, these are very prone to galling and will behave more like a new, rough, thread. Anti-seize helps to get a higher clamping force from Ti bolts.

 

[Ajax Bay]

Hands up who uses titanium bolts; and why? ('CycleChat' cycles not b****y cars or motorbikes.)

 

[Lookrider]

A lot of valuble and interesting input from many trades outside of bikes
Back to bikes I think you need to torque each fastener to the stated figures.......why.?
And without any professional qualifications..I would simply say ...why ...
BECAUSE THE FRAME MAKER SAY SO
The very best of engineers would not win a battle gone wrong because they knew all about torque up things by feel
Stick to the task plan..do as the manufactures ask

 

[Ajax Bay]

Why are you shouting? Why are you hectoring people to use a torque wrench for every fastening? Their use as a matter of routine makes sense for bikes and components not made of metal. Most bikes and components are, however, made of metal.
What's a "battle gone wrong"?

 

[winjim]

I'd just like to point out that 'fingertight plus a quarter turn' is a recognised torque setting in my field. In fact the fitting in question does have a specific torque wrench but the manual states fingertight plus ¼ so I guess that must be how it's calibrated...

 

[rogerzilla]

Hands up who uses titanium bolts; and why? ('CycleChat' cycles not b****y cars or motorbikes.)

I do. They're pretty common to save a few grams and/or avoid rust. Some, like stem expander bolts, save quite a lot of weight.

 

[Lookrider]

Why are you shouting? Why are you hectoring people to use a torque wrench for every fastening? Their use as a matter of routine makes sense for bikes and components not made of metal. Most bikes and components are, however, made of metal.
What's a "battle gone wrong"?

My apologoes for shouting ...I was not aware that big letters meant shouting
More I thought to stand out
I not sure what hectoring people but sorry if I was
My post meant do as tbe instructions say from the manufactures ...they to are engineers who test do tests and researching your bike was broke as a shop tightened something by feel
You would not get a replacement from the manufactures guarantee
Lord forbid a fatality again you would not stand up in court for doing torque by hand

 

[rogerzilla]

I'd just like to point out that 'fingertight plus a quarter turn' is a recognised torque setting in my field. In fact the fitting in question does have a specific torque wrench but the manual states fingertight plus ¼ so I guess that must be how it's calibrated...

Before I had a torque wrench, I used something similar for small M5 bolts. "Finger tight" was with the wrong end of the allen key, as hard as I could turn it (which is not very hard, given the tiny leverage). Then half a turn using the key the normal way round. I must try this and check the torque, but I bet it's in the right range.