Torque wrench
 

What's the appropriate range for a torque wrench for bike adjustments?

cc wrote:
What's the appropriate range for a torque wrench for bike
adjustments?

Some say 20-250 in-lbs.

This chart will give you some specs for various bicycle components:

http://www.parktool.com/repair_help/torque.shtml

so you would want something in this range if these components or
similar are being used.

cc wrote:
What's the appropriate range for a torque wrench for bike adjustments?



From about 50 inlbs for brake rotors (at least my Avids) to about 50
ftlbs for the fixed cup of a bottom bracket and lots in between.
Google torque wrench on this ng for a recent thread. You may need two
wrenches to cover the range.
FWIW, for most applications I use the "It shouldn't hurt to tighten it."
rule. The way this works is: With a normal sized wrench for the nut or
bolt my hand shouldn't hurt after pushing on the wrench. No dents in
the skin of my palm either (at least after a few seconds). And no extra
long allen wrenches, recipe for a stripped or broken bolt.

Shawn

cc wrote:
What's the appropriate range for a torque wrench for bike adjustments?

How long is your arm?

Shawn wrote:
cc wrote:
What's the appropriate range for a torque wrench for bike
adjustments?
From about 50 inlbs for brake rotors (at least my Avids) to about 50
ftlbs for the fixed cup of a bottom bracket and lots in between.
Google torque wrench on this ng for a recent thread. You may need two
wrenches to cover the range.
FWIW, for most applications I use the "It shouldn't hurt to tighten
it." rule. The way this works is: With a normal sized wrench for
the nut or bolt my hand shouldn't hurt after pushing on the wrench. No
dents in the skin of my palm either (at least after a few
seconds). And no extra long allen wrenches, recipe for a stripped or
broken bolt.

I would say extra long allen wrenches (2.5mm - 6mm) are a recipe for a
twisted wrench... bolts those sizes never yield, and 8-10mm wrenches torque
down no problem.

--
Phil, Squid-in-Training

cc wrote:
What's the appropriate range for a torque wrench for bike adjustments?

I have a 20-250 inlb clicker for small stuff and a beam type Craftsman for
the big stuff. Cost me about $90US plus hex/torx bits.

Mike

Phil, Squid-in-Training wrote:
Shawn wrote:

cc wrote:

What's the appropriate range for a torque wrench for bike
adjustments?

From about 50 inlbs for brake rotors (at least my Avids) to about 50
ftlbs for the fixed cup of a bottom bracket and lots in between.
Google torque wrench on this ng for a recent thread. You may need two
wrenches to cover the range.
FWIW, for most applications I use the "It shouldn't hurt to tighten
it." rule. The way this works is: With a normal sized wrench for
the nut or bolt my hand shouldn't hurt after pushing on the wrench. No
dents in the skin of my palm either (at least after a few
seconds). And no extra long allen wrenches, recipe for a stripped or
broken bolt.


I would say extra long allen wrenches (2.5mm - 6mm) are a recipe for a
twisted wrench... bolts those sizes never yield, and 8-10mm wrenches torque
down no problem.

Never yield? Never's a long time. I've seen plenty break, right at the
base of the head. And not *all* my fault. :-)
Usually though, what I've seen is that either the bolt head or the
wrench strips. Maybe it's the bolt/wrench tolerance, but to me it seems
like 5mm bolts can snap or strip easily, but 8 mm can handle more torque
than I can give. Go figger.

Shawn

"cc" wrote in message
...

What's the appropriate range for a torque wrench for bike adjustments?

Slack, slack-ish, medium, tight-ish, and snap - HTH, HAVVND.




Shaun aRe

I would say extra long allen wrenches (2.5mm - 6mm) are a recipe for a
twisted wrench... bolts those sizes never yield, and 8-10mm wrenches
torque down no problem.

Never yield? Never's a long time. I've seen plenty break, right at the
base of the head. And not *all* my fault. :-)
Usually though, what I've seen is that either the bolt head or the wrench
strips. Maybe it's the bolt/wrench tolerance, but to me it seems like 5mm
bolts can snap or strip easily, but 8 mm can handle more torque than I can
give. Go figger.

It's the effective force at each facet of the wrench. If you give 1Nm of
torque on a 1m wrench, the flats of a 5mm wrench will experience a little
less than 200N at the wrench/bolt interface, whereas the flats of a 8mm
wrench will experience only a little less than 125N. That's a reduction of
almost 40% with only a 3mm size difference.

I've broken cheap 5s that consist of metal bonded together with a seam
running down the middle... a poor excuse for a real tool. Forged tools are
the only way to go.

What kinds of bolt heads have you snapped, and on what specific part?

--
Phil, Squid-in-Training

Phil, Squid-in-Training wrote:
I would say extra long allen wrenches (2.5mm - 6mm) are a recipe for a
twisted wrench... bolts those sizes never yield, and 8-10mm wrenches
torque down no problem.


Never yield? Never's a long time. I've seen plenty break, right at the
base of the head. And not *all* my fault. :-)
Usually though, what I've seen is that either the bolt head or the wrench
strips. Maybe it's the bolt/wrench tolerance, but to me it seems like 5mm
bolts can snap or strip easily, but 8 mm can handle more torque than I can
give. Go figger.


It's the effective force at each facet of the wrench. If you give 1Nm of
torque on a 1m wrench, the flats of a 5mm wrench will experience a little
less than 200N at the wrench/bolt interface, whereas the flats of a 8mm
wrench will experience only a little less than 125N. That's a reduction of
almost 40% with only a 3mm size difference.

That 'splains it then, thanks.

I've broken cheap 5s that consist of metal bonded together with a seam
running down the middle... a poor excuse for a real tool. Forged tools are
the only way to go.

What kinds of bolt heads have you snapped, and on what specific part?

Brake cable binder bolts (SunTour road as well as cheapy ones in the
shops I've worked in).

Shawn