LBS and Torque Wrench

[Deleted member 26715]

Grabs spanner tightens bolt, many years later has it come loose, nope, must have been the right torque then.

 

[Lookrider]

Grabs spanner tightens bolts ..notice cracks many weeks / months later

Can I have a new bike under the lifetime guarantee ??

Each to there own choice to abide by manufacturers tried and tested R/D procedures

 

[Deleted member 26715]

Grabs spanner tightens bolts ..notice cracks many weeks / months later

Can I have a new bike under the lifetime guarantee ??

Each to there own choice to abide by manufacturers tried and tested R/D procedures

Your fault for tightening too tight then, can't have it all ways.

 

[Lookrider]

Your fault for tightening too tight then, can't have it all ways.

And exactky what a torque wrench prevents ...what it is meant for...and why they are recommended by the bike manufactures
Overtighten by hand at your own risk

 

[Ajax Bay]

What bike are you riding as your favourite, @Lookrider ? I'll be guessing it's not metal. Have you worked on a metal bike?

 

[FishFright]

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

One of my stems has Ti bolts but it's not attached to anything at the moment .

ETA , Torque wrenches are very handy for carbon steerers. I've seen a few come in to workshop with cracked steerers .

 

[Lookrider]

What bike are you riding as your favourite, @Lookrider ? I'll be guessing it's not metal. Have you worked on a metal bike?

Mix bikes made from aluminium ...steel ...carbon

 

[Foghat]

I bought a torque wrench some years ago. Read the instructions carefully. Set it to the recommended torque for stem bolts. Started doing them up. Thinks "Hmmm this is tight. Tighter than I normally do it. Still, it's a torque wrench, so I must have been doing it wrong all this time" ... PING! The bolt sheared.

Doubtless I was doing it wrong, but nonetheless I've never used it as a torque wrench since. It is a nice ratchet wrench though.

No, I don't own a carbon bike.

Similar here, but without the wrecking of any equipment.

After 25 years of all kinds of expert mechanicking on high-end bikes, in 2009 I bought the Park Tool Small Clicker and Big Clicker torque wrenches. Turned out I didn't need them, though.

Having been doing it for so long, I knew exactly, by feel, how tight was tight enough for all manner of materials and components on bikes - never shearing bolts or stripping threads or cracking anything through overtightening, and things coming loose so rarely that if it did happen, I can't remember any occasions (maybe a mudguard bolt once - and that was probably forgetfulness rather than misjudgement).

But like you, when I went to use the torque wrench, having set it to the appropriate value, when I started tightening, it carried on tightening way past what felt normal/right......and because the Park wrenches have longer levers than the non-torque tools I normally use, I was certain it was going much too far so aborted the manoeuvre before any damage was caused. Maybe it was duff, or hadn't been calibrated, who knows, but since then, the two torque wrenches have made nice comfortable differently-proportioned ratchets, and I've spent a further 11 years using non-torque tools and never damaging any of my bikes by overtightening through not knowing when to stop or what feels right.

I do have carbon bikes!

 

[SkipdiverJohn]

.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

If a component suffers a total failure, the torque loading disappears because the reaction medium to the fastener that is under tensile load is no longer there. If you pick up a nut and bolt and screw them together there is almost no torque involved unless you put the bolt through a hole and give the bolt head and nut something to react on.
If someone later examines a failed fastener, they can only tell if it has been torqued beyond it's yield point, because the thing will be thinner and longer than it should be. If it was overtightened but fell short of the yield point, then no-one would be able to tell for certain because the elongation of the fastener when torqued would have been elastic.

 

[randynewmanscat]

I started to rebuild my touring bike today, only been off the road for 4 years now. A chance to indulge in cycle parts porn and tool porn on a Sunday afternoon. Always used 11Nm, always used steel bolts and alu chainrings. I have many torque control tools and they all must have a cert every 6 months or 3,000 cycles. The most expensive digital ones with data output have cycle counters, I don't because I'm a cheapskate.

 

[Ajax Bay]

Hope you used threadlock on those chainring bolts.

 

[figbat]

A torque wrench used dogmatically can be worse than a sympathetically used spanner. It’s like my dad used to tell me about using a calculator - you have to at least have some idea what answer you are expecting or what order of magnitude; same with a torque wrench - you have to have an idea what feels ok. I’ll use one for torque-critical components but more often than not will go by feel, on any and all frame or component materials. It has been decades since I last sheared a bolt (the last I can remember was a thermostat housing bolt on a 1977 Mini, sheared in 1991).

 

[randynewmanscat]

Hope you used threadlock on those chainring bolts.

Loctite 222.

 

[randynewmanscat]

A torque wrench used dogmatically can be worse than a sympathetically used spanner. It’s like my dad used to tell me about using a calculator - you have to at least have some idea what answer you are expecting or what order of magnitude; same with a torque wrench - you have to have an idea what feels ok. I’ll use one for torque-critical components but more often than not will go by feel, on any and all frame or component materials. It has been decades since I last sheared a bolt (the last I can remember was a thermostat housing bolt on a 1977 Mini, sheared in 1991).

I use them very dogmatically when rebuilding assemblies subjected to +900 MPa.

 

[figbat]

I use them very dogmatically when rebuilding assemblies subjected to +900 MPa.

That’s what I might describe as a “torque-critical component”. I’d wager you’re doing it with some knowledge and experience too.

On a torque-related tangent, years ago I attended a training course delivered by a major ship engine designer. They laboured the point of torque settings and whether dry or lubricated at some length (as you can imagine given the size, power and cost of the engines in question). But it was amusing to note that the cylinder head stud nuts on these biggest of engines are done up hand-tight. Of course the studs are stretched with a hydraulic puller first, but the nuts are run on by hand.