Are torque wrenches really necessary?
#1
Senior Member
Thread Starter
Join Date: Jul 2015
Posts: 90
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Are torque wrenches really necessary?
I've been getting into doing my own maintenance like drive train cleaning with chains, cassettes, and chainrings off the bike and soaking them in degreaser.
I've changed a few pedals and stems before and am in the process of switching to new cassettes and chainrings.
Is it essential that I follow all the torque specs closely? When I take my bike to LBS, I see the mechanics working on things without a torque wrench. It seems they just go with their feel. They've probably done it so many times that they probably know mostly what parts requires what Nm and how much force to put in their arms by feel.
I did buy a small 1/4" drive torque wrench set that only goes up to 25Nm so I use that for the more delicate parts with low torque specs. For example, my stem indicates not to exceed 4Nm so I torque it slightly below that. The lockring on the cassette however, indicates 40Nm. I don't have a socket bit big enough to fit a lockring tool so I just try to tighten enough without going too tight (just by feel). My crankarm indicates 48-53 Nm but I go up to 25Nm with my torque wrench and then use a regular hex wrench to go some more but I have no idea what actual torque it is ending up.
Are these torque specs all essential to follow and thus a bigger torque wrench necessary? How do you guys work on your bikes?
Thanks.
I've changed a few pedals and stems before and am in the process of switching to new cassettes and chainrings.
Is it essential that I follow all the torque specs closely? When I take my bike to LBS, I see the mechanics working on things without a torque wrench. It seems they just go with their feel. They've probably done it so many times that they probably know mostly what parts requires what Nm and how much force to put in their arms by feel.
I did buy a small 1/4" drive torque wrench set that only goes up to 25Nm so I use that for the more delicate parts with low torque specs. For example, my stem indicates not to exceed 4Nm so I torque it slightly below that. The lockring on the cassette however, indicates 40Nm. I don't have a socket bit big enough to fit a lockring tool so I just try to tighten enough without going too tight (just by feel). My crankarm indicates 48-53 Nm but I go up to 25Nm with my torque wrench and then use a regular hex wrench to go some more but I have no idea what actual torque it is ending up.
Are these torque specs all essential to follow and thus a bigger torque wrench necessary? How do you guys work on your bikes?
Thanks.
#2
On Your Left
Join Date: Nov 2011
Location: Long Island, New York, USA
Posts: 8,373
Bikes: Trek Emonda SLR, Sram eTap, Zipp 303
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 3004 Post(s)
Liked 2,433 Times
in
1,187 Posts
Unless your hand has been calibrated, i'd get a torque wrench.
The risk of over torquing and damaging a carbon frame is just not worth it... to me.
The risk of over torquing and damaging a carbon frame is just not worth it... to me.
#3
Super Moderator
Join Date: Jul 2004
Location: Ffld Cnty Connecticut
Posts: 21,843
Bikes: Old Steelies I made, Old Cannondales
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1173 Post(s)
Liked 927 Times
in
612 Posts
No they are not necessary. More useful for some people than others.
__________________
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.
FYI: https://www.bikeforums.net/forum-sugg...ad-please.html
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.
FYI: https://www.bikeforums.net/forum-sugg...ad-please.html
#4
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,716
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5788 Post(s)
Liked 2,580 Times
in
1,430 Posts
IMO, not necessary and there's no reason to design and build bikes an a way that they are.
Most of the torque specs published and heeded so strictly, miss the point. Most fasteners on bikes need to be tightened enough to do the job, and n o more. For example, the toque spec given for stem clamp bolts aren't truly relevant to the task. The required torque is more related to the fit and traction between the stem and fork than anything else. Since that varies so much, it's naive to believe that a published torque has any hope of being right.
Torque specs, are useful as guides for mechanics, but with any experience, and willingness to trust your hands, the screw itself will tell you when it's properly tight.
If having a torque wrench makes you more confident, then buy it, but don't consider it a substitute for being aware of what's happening.
Most of the torque specs published and heeded so strictly, miss the point. Most fasteners on bikes need to be tightened enough to do the job, and n o more. For example, the toque spec given for stem clamp bolts aren't truly relevant to the task. The required torque is more related to the fit and traction between the stem and fork than anything else. Since that varies so much, it's naive to believe that a published torque has any hope of being right.
Torque specs, are useful as guides for mechanics, but with any experience, and willingness to trust your hands, the screw itself will tell you when it's properly tight.
If having a torque wrench makes you more confident, then buy it, but don't consider it a substitute for being aware of what's happening.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#5
Senior Member
Join Date: Dec 2012
Location: Okefenokee Swamps.
Posts: 577
Bikes: Rockhopper, Azor Oma cruiser
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
When I started using a 3/8ths drive Snap On torque wrench on my vehicle and torqued all the bolts to spec on the short block, the vacuum at idle increased by five inches.
#6
Senior Member
Join Date: May 2008
Location: Zang's Spur, CO
Posts: 9,083
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3375 Post(s)
Liked 5,517 Times
in
2,859 Posts
I always use a torque wrench on tapered BB's and cassette lockrings.
I learned the hard way that my idea of "tight enough" was not accurate on either of these.
I learned the hard way that my idea of "tight enough" was not accurate on either of these.
#7
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
If you're not a hamfist, no.
#8
Senior Member
Join Date: Apr 2014
Location: SF Bay Area
Posts: 681
Bikes: the bikes own me
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 4 Times
in
3 Posts
I've wrenched on all kinds of stuff from bikes to cars to boats and snowmobiles and motorcycles to go karts and lawn mowers to paper converting equipment and GE gas turbine engine. My dad taught Diesel Mechanics at a tech school so every summer brought a new project. I think torque wrenches are valuable tools when you are first getting aquainted with being a mechanic but grow less necessary over time as you get the feel for fasteners. That said I wouldn't assemble an engine without one. One thing some people overlook is the importance of using good quality fasteners that are in good condition and knowing when you can re-use a fastener and when you should throw them away. A bunged up thread can seize a nut on a bolt and give you the torque spec you're looking for without actually doing the clamping work you need the fastener to do.
My favorite bit of advice to give new mechanics is "tighten the bolt until you feel it getting loose again then back off a quarter turn". Of course this is nonsense if you feel it getting loose then you've stripped the threads
My favorite bit of advice to give new mechanics is "tighten the bolt until you feel it getting loose again then back off a quarter turn". Of course this is nonsense if you feel it getting loose then you've stripped the threads
#9
Advocatus Diaboli
Join Date: Feb 2015
Location: Wherever I am
Posts: 8,636
Bikes: Merlin Cyrene, Nashbar steel CX
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Quoted: 4735 Post(s)
Liked 1,532 Times
in
1,003 Posts
My understanding is that many of the torque specs are for the screws themselves. Going above the spec risks damage to the threads. People talk about torque specs on their stems and seatpost clamps, etc.. and refer to these ratings as guidelines to avoid damage to the clamped items (ie. the handlebars and seatpost). However the obvious problem with this theory is that the seatpost clamp maker and stem maker, have no idea what model, material or make of item you're going to be clamping -- CF, Alloy, Stainless Steel, and build/wall thickness, etc..
The torque values are to prevent you irreparably damaging the actual threads of the screw/bolt itself.
The torque values are to prevent you irreparably damaging the actual threads of the screw/bolt itself.
#10
Bad example
Join Date: Nov 2015
Location: Seattle and Reims
Posts: 3,068
Bikes: Peugeot: AO-8 1973, PA-10 1971, PR-10 1973, Sante 1988; Masi Gran Criterium 1975, Stevenson Tourer 1980, Stevenson Criterium 1981, Schwinn Paramount 1972, Rodriguez 2006, Gitane Federal ~1975, Holdsworth Pro, Follis 172 ~1973, Bianchi '62
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 825 Post(s)
Liked 212 Times
in
96 Posts
I've never used one. However, years ago I learned that I could over-torque bolts enough to strip the threads in cheap aluminum parts. Since then, I have made sure to use only high-end, strongly made parts and I have not had any issues.
My confession is true. I am sure that since that time I have gotten much better at gauging torque when I tighten a bolt, but I still don't use a torque wrench. All that said, I wish I had gotten a small torque wrench ages ago, so that I would not have had to learn all this by trial and error (which means destroying components.)
My confession is true. I am sure that since that time I have gotten much better at gauging torque when I tighten a bolt, but I still don't use a torque wrench. All that said, I wish I had gotten a small torque wrench ages ago, so that I would not have had to learn all this by trial and error (which means destroying components.)
#12
On Your Left
Join Date: Nov 2011
Location: Long Island, New York, USA
Posts: 8,373
Bikes: Trek Emonda SLR, Sram eTap, Zipp 303
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 3004 Post(s)
Liked 2,433 Times
in
1,187 Posts
I thought it was "tighten it until it snaps then back it off a 1/4 turn".
#14
Senior Member
Join Date: Aug 2010
Location: NorCal
Posts: 120
Bikes: '17 Cannondale SuperSix Hi-Mod, '11 Cannondale Supersix, '13 Cannondale CAADX Disc, '13 Trek Superfly, '07 Cannondale System Six
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Yes, get a good ft/lb and in/lb torque wrench and no more guesswork.
#15
Senior Member
Join Date: Apr 2005
Location: Northern California
Posts: 10,879
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Likes: 0
Liked 5 Times
in
5 Posts
Lots of beginners over-tighten seatpost bolts and stem bolts, causing irreparable damage to seatposts and forks. If you use the smallest possible wrenches (for minimal leverage) and tend to under-tighten bolts, then maybe you don't need a torque wrench. If you're ham-fisted with lightweight components, then you do need it.
#16
Thread Killer
Join Date: Aug 2008
Location: Ann Arbor, MI
Posts: 12,446
Bikes: 15 Kinesis Racelight 4S, 76 Motebecane Gran Jubilée, 17 Dedacciai Gladiatore2, 12 Breezer Venturi, 09 Dahon Mariner, 12 Mercier Nano, 95 DeKerf Team SL, 19 Tern Rally, 21 Breezer Doppler Cafe+, 19 T-Lab X3, 91 Serotta CII, 23 3T Strada
Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 3144 Post(s)
Liked 1,708 Times
in
1,032 Posts
I've not put a torque wrench to a bike in my 30 years of maintaining my little stable of bikes. I got my first carbon fiber bars and seatposts in the early '90s, and often run a mix of bolt materials; my two main roadies now have Ti, aluminum and stainless bolts. Never had any troubles.
#17
Farmer tan
I got by for decades wrenching on stuff bikes with pliers and adjustable wrench.
#18
Senior Member
Join Date: Jun 2014
Location: California
Posts: 1,300
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
If you tend to build a bike from scratch, and do most of the work/repairs at home then it could be helpful. Especially with lightweight carbon pieces.
For the standard cyclist, probably not. I just use the Ritchey 5nm tool for adjusting seatpost/stem/steerer tube. Really just piece of mind for me, but I guess it also stops me from over torquing.
Next thing people will craze about is proper torque for a quick-release skewer. It is a carbon part, proper torque must be quantified!
For the standard cyclist, probably not. I just use the Ritchey 5nm tool for adjusting seatpost/stem/steerer tube. Really just piece of mind for me, but I guess it also stops me from over torquing.
Next thing people will craze about is proper torque for a quick-release skewer. It is a carbon part, proper torque must be quantified!
#19
Senior Member
Join Date: Jan 2013
Posts: 215
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Back in the days of tapered bb spindles, I would occasionally have my left crank fall off. I bought a torque wrench and found that I was only torque to 1/2 the recommended value. Problem solved.
You're not going to get any consistency if you just torque by feel. Different feels depending on handle shape and length.
That said, being ballpark close is close enough; you don't have to be exact. But if you need a torque wrench just be be close, why not use one as a matter of course.
You're not going to get any consistency if you just torque by feel. Different feels depending on handle shape and length.
That said, being ballpark close is close enough; you don't have to be exact. But if you need a torque wrench just be be close, why not use one as a matter of course.
#21
Zoom zoom zoom zoom bonk
Join Date: Sep 2006
Location: New Zealand
Posts: 4,624
Bikes: Giant Defy, Trek 1.7c, BMC GF02, Fuji Tahoe, Scott Sub 35, Kona Rove, Trek Verve+2
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 551 Post(s)
Liked 722 Times
in
366 Posts
If you use teeny tiny bolts on your handlebars and CF seatposts then yes.
#22
Senior Member
Join Date: Dec 2010
Location: Above ground, Walnut Creek, Ca
Posts: 6,681
Bikes: 8 ss bikes, 1 5-speed touring bike
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Likes: 0
Liked 4 Times
in
4 Posts
i thought it went... "tighten it until just before it snaps then back it off a 1/4 turn". but i'm prepared to be corrected on an international public forum, ...again.
Last edited by hueyhoolihan; 12-06-15 at 01:59 AM.
#23
Senior Member
Join Date: Apr 2010
Location: Mountain View, CA USA and Golden, CO USA
Posts: 6,341
Bikes: 97 Litespeed, 50-39-30x13-26 10 cogs, Campagnolo Ultrashift, retroreflective rims on SON28/PowerTap hubs
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 550 Post(s)
Liked 325 Times
in
226 Posts
Some do, or at least "appropriate length" departs from standard wrenches.
Lots of people (including some bike shop mechanics) don't get crank arms tight enough which can result in them getting loose at which point they move, open the taper they rely on for a press fit, and are ruined.
This still applies to splined cranks which don't have separate pinch bolts - they have a slight taper on the mating surfaces (ISIS used 1 degree) with installation stretching the crank arm until it bottoms against a shoulder on the spindle.
Last edited by Drew Eckhardt; 12-06-15 at 09:37 AM.
#24
Senior Member
Join Date: Apr 2010
Location: Mountain View, CA USA and Golden, CO USA
Posts: 6,341
Bikes: 97 Litespeed, 50-39-30x13-26 10 cogs, Campagnolo Ultrashift, retroreflective rims on SON28/PowerTap hubs
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 550 Post(s)
Liked 325 Times
in
226 Posts
#25
Senior Member
Join Date: May 2008
Location: Zang's Spur, CO
Posts: 9,083
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3375 Post(s)
Liked 5,517 Times
in
2,859 Posts