No more need for a torque wrench?

Binaural

Binaural

Eats Squid
Bike bolt tensions are specified far more tightly than industrial bolts as the safety margin is a lot lower. Using an accurate torque wrench and loctite is a much better idea than relying on more complicated bolts.
 
Dales Cannon

Dales Cannon

lightbrain about 4pm
Staff member
To clarify a bit. Those pretty stainless M5 bolts that hold the stem on are typically tensioned to 6Nm whereas the bolt is probably good for 15 or more Nm.
 
Warp

Warp

Likes Dirt
Binaural said:
Bike bolt tensions are specified far more tightly than industrial bolts as the safety margin is a lot lower. Using an accurate torque wrench and loctite is a much better idea than relying on more complicated bolts.
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Which in my dumb opinion is nonsense. MTB's are off-road vehicles subject to abuse, not a Formula 1 car.

I understand the requirements of being light, strong, yada, yada... I stick with my point.
 
ozzybmx

ozzybmx

taking a shit with my boobs out
Warp said:
Which in my dumb opinion is nonsense. MTB's are off-road vehicles subject to abuse, not a Formula 1 car.
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There are as many bolts and screws torqued to the optimal tension on a World Cup DH bike as there are on a light XC bike.

Look as it as the perfect tension to get 100% out of the bolt, 100% out of what the bolt is holding and the highest probability of the rider not having any of their parts fail.

The other option is to make stuff out of thick steel and use high tension bolts... and enjoy your 25kg bike.

Just used mine this afternoon to torque up pivot bolts, I don't use it very often but dont fancy stripping suspension/Pivot bolts or the frame that it screws into.
 
Nambra

Nambra

Definitely should have gone to specsavers
Don’t see them working very well on bikes with predominantly hex/torx bit bolts - you wouldn’t be able to see the coloured bit as you’re tightening them!

Interesting concept though, definitely useful for other applications.
 
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M

mas2

Likes Bikes and Dirt
Nambra said:
Don’t see them working very well on bikes with prominently hex/torx bit bolts - you wouldn’t be able to see the coloured bit as you’re tightening them!

Interesting concept though, definitely useful for other applications.
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When I posted this I was thinking about it more as a concept and how it could be applied to bikes. Even if you couldn't see the coloured bit if you just tightened them like normal with a torque wrench and then every now and then just give your bike a quick look over and if you see a red circle tighten it up a bit. More like a safety device.
 
Nambra

Nambra

Definitely should have gone to specsavers
Fair point - might be of use to those not too mechanically minded.
 
Jpez

Jpez

Down on the left!
I have a torque wrench but since I’ve kinda learnt how tight is tight is enough I don’t really use it any more. I don’t have any carbon though.
Am I bad?
 
mik_git

mik_git

Likes Bikes and Dirt
Jpez said:
I have a torque wrench but since I’ve kinda learnt how tight is tight is enough I don’t really use it any more. I don’t have any carbon though.
Am I bad?
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Yes...
Although I've had loads of carbon stuff over the years and never used one.
 
John U

John U

MTB Precision
Although there’s a fuck tonne of variables such as age and wear, I’d like to see locations where bolts needed to be torqued specifically labeled clearly, wherever they are. Would be a big help, even if going by feel. Would also help as bikes age and information about the bike gets harder to find.
 
Binaural

Binaural

Eats Squid
Jpez said:
I have a torque wrench but since I’ve kinda learnt how tight is tight is enough I don’t really use it any more. I don’t have any carbon though.
Am I bad?
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That custom title was quick, hahaha. Most screws and bolts have an enormous tolerance range, and you are frankly more likely to damage most parts by misthreading than you are by over-torquing. I'd still recommend getting a torque wrench for carbon bars or seatpoosts though, there's a loooot of posts out there from otherwise competent mechanics who managed to crack something expensive.
 
Flow-Rider

Flow-Rider

Burner
John U said:
Although there’s a fuck tonne of variables such as age and wear, I’d like to see locations where bolts needed to be torqued specifically labeled clearly, wherever they are. Would be a big help, even if going by feel. Would also help as bikes age and information about the bike gets harder to find.
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The biggest mistake people make is not properly cleaning the threads on the bolts and bolt holes and then expect to get the right tension. Then you have specifics like dry or wet thread tension specs, burrs under the heads of the bolts and or reusing old bolts and washers.
 
Warp

Warp

Likes Dirt
ozzybmx said:
There are as many bolts and screws torqued to the optimal tension on a World Cup DH bike as there are on a light XC bike.

Look as it as the perfect tension to get 100% out of the bolt, 100% out of what the bolt is holding and the highest probability of the rider not having any of their parts fail.

The other option is to make stuff out of thick steel and use high tension bolts... and enjoy your 25kg bike.

Just used mine this afternoon to torque up pivot bolts, I don't use it very often but dont fancy stripping suspension/Pivot bolts or the frame that it screws into.
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Sure I respect that. And again, I understand the implications. For me, for carbon bits is a needed due to the characteristics of the material.
On alloy parts I've never used one.

Most L shaped allen/hex wrenches start flexing when they get close to the recommended torque for the bolt, you can feel it in your hand. Most wrenches have a handle size that is pretty much according the amount of torque you can put with/on them. Problem start when you have a 1/2" driver with a 4mm bit to make a silly example. You can easily damage something in that situation.

Flow-Rider and Binaural make pretty solid points too regarding cross threading and damaging threads.
Thread preparation is key.
 
Binaural

Binaural

Eats Squid
Flow-Rider said:
The biggest mistake people make is not properly cleaning the threads on the bolts and bolt holes and then expect to get the right tension. Then you have specifics like dry or wet thread tension specs, burrs under the heads of the bolts and or reusing old bolts and washers.
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It's interesting, but loctite recommend you don't change the torque value when using their stuff to get the right tension. And my understanding is that you should treat all bolt torque specs as being with grease or oil, because you should be doing that to minimise corrosion risk anyway.
 
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