View Poll Results: Do I need a torque wrench to install brake rotors
Yes
13
41.94%
No, a good guestimate of 3 to 6 Nm is good enough
18
58.06%
Voters: 31. You may not vote on this poll
Do I need a torque wrench to install rotors?
#1
Senior Member
Thread Starter
Join Date: Oct 2015
Location: San Diego, California
Posts: 4,077
Bikes: Velo Orange Piolet
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 2228 Post(s)
Liked 2,011 Times
in
972 Posts
Do I need a torque wrench to install rotors?
Yes.
No - a guestimate between 3 and 6 Nm is good enough, as long as it's consistent between the 6 bolts and sequenced in the proper star sequence.
No - a guestimate between 3 and 6 Nm is good enough, as long as it's consistent between the 6 bolts and sequenced in the proper star sequence.
#2
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,053
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4194 Post(s)
Liked 3,837 Times
in
2,295 Posts
Now I have no problem maintaining a false belief if it makes us pay more attention and take due care to insure a correct outcome. But in my eyes that is what is cross tightening is for bicycle disk brake rotor bolts. Andy
__________________
AndrewRStewart
AndrewRStewart
#3
Senior Member
Join Date: Oct 2007
Location: West Yorkshire, United Kingdom
Posts: 5,773
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 453 Post(s)
Liked 104 Times
in
87 Posts
Go by the rotors instructions, yes, when I worked in a LBS, we did it with a digital torque wrench, for personal use, no, have been using discs for pushing 20 years and not had any bolts come loose, I do with centerlocks, simply as they are the same setup torque wrench wise as a cassette install.
Likes For jimc101:
#5
Senior Member
Join Date: Jun 2009
Location: Land of Enchantment
Posts: 468
Bikes: Domane SLR7 Project One
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 152 Post(s)
Liked 173 Times
in
105 Posts
Haven't had to change out rotors yet but when the time comes I'll use a torque wrench. I've gotten to the point where I torque just about everything on the bike. I figure I've since spent the money on the torque wrenches I might as well use them.
#6
Occam's Rotor
Join Date: Jul 2013
Posts: 7,248
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 2,331 Times
in
1,164 Posts
It is easy to damage a soft aluminum thread in a hub if you over-tighten or mis-thread a bolt. The problems of too loose bolts should be obvious.
You could probably get away with having only three of the six bolts in, if they are symmetrically disposed. The point is to have some redundancy, and having each bolt torqued the same amount contributes to that.
You could probably get away with having only three of the six bolts in, if they are symmetrically disposed. The point is to have some redundancy, and having each bolt torqued the same amount contributes to that.
#7
Senior Member
Join Date: Feb 2017
Location: Northern Shenandoah Valley
Posts: 4,138
Bikes: More bikes than riders
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 1443 Post(s)
Liked 759 Times
in
568 Posts
I've experienced the effect of loose bolts, in the form of the disc rotating on the hub when rocking the bike back and forth. It seemed to be more than just the pads shifting in the caliper, and indeed discovered that the disc itself was shifting. Combining this with the unsavory possibility of stripping a hole in the hub, I've used a torque wrench to install discs ever since.
#8
Banned
I have access to a preset click torque wrench with a Torx bit in it.. for disc brakes .. in the LBS..
You can buy a preset torque key if you do a lot of them.. know what torque is specified?
but ... after decades of dealing with 5 mm bolts, on bikes in the shop,
You may need a torque wrench I do Not.
...
You can buy a preset torque key if you do a lot of them.. know what torque is specified?
but ... after decades of dealing with 5 mm bolts, on bikes in the shop,
You may need a torque wrench I do Not.
...
Last edited by fietsbob; 08-09-20 at 03:12 PM.
#9
Senior Member
Install it with a cordless drill, with the torque setting at some reasonable point and use a dab of loctite. At least then you know they are all torqued the same and wont fall out. I just made that up in my head. Never tried it ;-)
#10
Non omnino gravis
Well, I install mine with one of these,
A 12V Bosch Impactor, fitted with one of the countless 2" T25 bits I have from buying equally countless boxes of decking screws. I give each bolt a brrt-brrt-brrt from the impact driver, and tighten in criss-cross. Like on a car.
Never had a bolt loosen at all. Miles: lots.
A 12V Bosch Impactor, fitted with one of the countless 2" T25 bits I have from buying equally countless boxes of decking screws. I give each bolt a brrt-brrt-brrt from the impact driver, and tighten in criss-cross. Like on a car.
Never had a bolt loosen at all. Miles: lots.
#11
Advanced Slacker
Join Date: Feb 2017
Posts: 6,210
Bikes: Soma Fog Cutter, Surly Wednesday, Canfielld Tilt
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2761 Post(s)
Liked 2,534 Times
in
1,433 Posts
Been using discs since 2001. Never used a torque wrench for the rotor bolts, even though I have one that I use for other things. Never had one come loose or strip any threads.
Not making a recommendation for what others should do, as I don’t know how ham-fisted others are.
Not making a recommendation for what others should do, as I don’t know how ham-fisted others are.
#12
Senior Member
Thread Starter
Join Date: Oct 2015
Location: San Diego, California
Posts: 4,077
Bikes: Velo Orange Piolet
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 2228 Post(s)
Liked 2,011 Times
in
972 Posts
I was thinking just get a tool like this and crank it down almost as hard as I can with only 4 inches of leverage:
#13
Advanced Slacker
Join Date: Feb 2017
Posts: 6,210
Bikes: Soma Fog Cutter, Surly Wednesday, Canfielld Tilt
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2761 Post(s)
Liked 2,534 Times
in
1,433 Posts
Likes For Kapusta:
#14
Occam's Rotor
Join Date: Jul 2013
Posts: 7,248
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 2,331 Times
in
1,164 Posts
Well, I install mine with one of these,
A 12V Bosch Impactor, fitted with one of the countless 2" T25 bits I have from buying equally countless boxes of decking screws. I give each bolt a brrt-brrt-brrt from the impact driver, and tighten in criss-cross. Like on a car.
Never had a bolt loosen at all. Miles: lots.
A 12V Bosch Impactor, fitted with one of the countless 2" T25 bits I have from buying equally countless boxes of decking screws. I give each bolt a brrt-brrt-brrt from the impact driver, and tighten in criss-cross. Like on a car.
Never had a bolt loosen at all. Miles: lots.
#17
Heft On Wheels
Join Date: Nov 2014
Location: South Dakota
Posts: 3,123
Bikes: Specialized,Cannondale,Argon 18
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 887 Post(s)
Liked 560 Times
in
346 Posts
It is my very humble opinion that anyone who works on a bike should absolutely be using a torque wrench
#18
Senior Member
Yes. These are your brakes, not a seatpost bolt. The tightness of each bolt must be the same or the rotor can warp (bad) or work loose ("more badder"). Others will argue that you don't need to torque, but why? If you have a torque wrench or can borrow one, why wouldn't you torque them down?
..
..
Last edited by drlogik; 06-02-19 at 09:04 PM.
#19
Senior Member
No, you don't need one.
But buy one and use it anyway. You'll also use it on other stuff that has a specific torque requirement, like carbon parts.
But buy one and use it anyway. You'll also use it on other stuff that has a specific torque requirement, like carbon parts.
#20
Advanced Slacker
Join Date: Feb 2017
Posts: 6,210
Bikes: Soma Fog Cutter, Surly Wednesday, Canfielld Tilt
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2761 Post(s)
Liked 2,534 Times
in
1,433 Posts
#21
Advanced Slacker
Join Date: Feb 2017
Posts: 6,210
Bikes: Soma Fog Cutter, Surly Wednesday, Canfielld Tilt
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2761 Post(s)
Liked 2,534 Times
in
1,433 Posts
Rotor bolts are really not that hard to get right. Tight enough to not come loose, but not so tight that you strip the threads or break off the bolt heads. For people who wrench regularly, that is pretty simple. There is no risk of crushing the rotor or having it slip.
Things like seatpost clamps and stem face-plates are a different story. you need to get the torque high enough to keep the seatpost/bar from slipping, but not too high to crush/damage it, and it is really hard to know what that feels like when tightening.
But like someone else said, even if you don't use a torque wrench for rotor bolts, you should still get one for all the parts that you DO want one.
Things like seatpost clamps and stem face-plates are a different story. you need to get the torque high enough to keep the seatpost/bar from slipping, but not too high to crush/damage it, and it is really hard to know what that feels like when tightening.
But like someone else said, even if you don't use a torque wrench for rotor bolts, you should still get one for all the parts that you DO want one.
#22
Senior Member
Join Date: Aug 2009
Location: Minneapolis
Posts: 5,750
Bikes: 2022 Salsa Beargrease Carbon Deore 11, 2020 Salsa Warbird GRX 600, 2020 Canyon Ultimate CF SLX disc 9.0 Di2, 2020 Catrike Eola, 2016 Masi cxgr, 2011, Felt F3 Ltd, 2010 Trek 2.1, 2009 KHS Flite 220
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 4361 Post(s)
Liked 3,000 Times
in
1,853 Posts
How about for centerlock rotors? Recommendation is 40 Nm.
I have a torque wrench, but not one that goes to 40 Nm and I don't have a ratchet large enough to fit over the Lockring tool. Also, I don't see much other need for having a torque wrench that goes to such high torques. Certainly I've never felt the need for one in order to install a cassette. Is this different?
These seem less finicky than the rotors with multiple bolts. Seems I should be able to wrench it down tight without being in danger of making it too loose or damaging the threads?
No?
I have a torque wrench, but not one that goes to 40 Nm and I don't have a ratchet large enough to fit over the Lockring tool. Also, I don't see much other need for having a torque wrench that goes to such high torques. Certainly I've never felt the need for one in order to install a cassette. Is this different?
These seem less finicky than the rotors with multiple bolts. Seems I should be able to wrench it down tight without being in danger of making it too loose or damaging the threads?
No?
#23
Senior Member
Join Date: Jun 2002
Location: Montreal, Quebec
Posts: 5,920
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1814 Post(s)
Liked 1,692 Times
in
973 Posts
I have always felt this "cross tightening" method, which is what I was taught to do on car wheel studs/bolts, is nonsense for a bike rotor. The rotor will just bend and take to whatever surface flatness (or not) that the hub is faced off at. I don't think there's anyway a rotor could induce a warping to the hub, and since we gladly true a rotor any run out of it is easily dealt with (whether or not run out is hub induced or in the rotor before installing).
Now I have no problem maintaining a false belief if it makes us pay more attention and take due care to insure a correct outcome. But in my eyes that is what is cross tightening is for bicycle disk brake rotor bolts. Andy
Now I have no problem maintaining a false belief if it makes us pay more attention and take due care to insure a correct outcome. But in my eyes that is what is cross tightening is for bicycle disk brake rotor bolts. Andy
#24
FLIR Kitten to 0.05C
Join Date: Sep 2014
Location: Lincoln, Nebraska
Posts: 5,331
Bikes: Roadie: Seven Axiom Race Ti w/Chorus 11s. CX/Adventure: Carver Gravel Grinder w/ Di2
Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 2349 Post(s)
Liked 406 Times
in
254 Posts
How about for centerlock rotors? Recommendation is 40 Nm.
I have a torque wrench, but not one that goes to 40 Nm and I don't have a ratchet large enough to fit over the Lockring tool. Also, I don't see much other need for having a torque wrench that goes to such high torques. Certainly I've never felt the need for one in order to install a cassette. Is this different?
These seem less finicky than the rotors with multiple bolts. Seems I should be able to wrench it down tight without being in danger of making it too loose or damaging the threads?
No?
I have a torque wrench, but not one that goes to 40 Nm and I don't have a ratchet large enough to fit over the Lockring tool. Also, I don't see much other need for having a torque wrench that goes to such high torques. Certainly I've never felt the need for one in order to install a cassette. Is this different?
These seem less finicky than the rotors with multiple bolts. Seems I should be able to wrench it down tight without being in danger of making it too loose or damaging the threads?
No?
#25
Advanced Slacker
Join Date: Feb 2017
Posts: 6,210
Bikes: Soma Fog Cutter, Surly Wednesday, Canfielld Tilt
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2761 Post(s)
Liked 2,534 Times
in
1,433 Posts
This is not rocket science. Just tighten until the bolt head breaks free and back off 1/8 turn.