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All 650's What torque wrench to get?

Jerry

2016
CBR650F ABS
May 18, 2017
The Netherlands
I've been looking to buy my own torque wrench which I'll mostly be using on the rear axle nut and the lock nuts. The first requires 98Nm and the latter requires 27Nm. I've been looking at which wrenches are available and for some reason, all wrenches seem to either allow for really low torques (4 - 30 Nm or so) or starting at 28Nm and going up into the range of ~200Nm.
Would it be ok for me to use a 28Nm torque wrench to tighten bolts listed as 27Nm? Actually, the oil drain bolt is listed as 26Nm. Would 28Nm be a problem? I must admit I don't really know how big of a difference 1 or 2 Nm makes. But it also feels a bit silly to having to buy two separate wrenches for such a small difference.
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Some facts that go into a torque wrench, my dad was the head of mechanical calibration for a major welder manufacturer for 20+ years and tested and calibrated things like gauges and torque wrenches:

- You'll never find one torque wrench that will cover all the bolts and fasteners on a motorcycle so you need to plan for at least two if you are going to service your bike.

- The smaller the fastener, the more precise you need to be with its setting, so things like drain pans bolts, engine covers, fork clamps, etc. are easier to overtighten than say your rear axle.

- Another thing to note is a torque wrench is a calibrated device with a “useable” range, as you said, some start at 28Nm, but know they are less accurate at their extremes (top and bottom of their range). The only ones that are not that way are the beam type units.

- Fasteners normally have a 10% tolerance to them

- You generally have 3 drive sizes of socket wrenches, 1/4”, 3/8” and 1/2” (at least that’s what they are in the US) for different sizes sockets, so you’ll find 3 sizes of torque wrench drives.

So having said all of that, I’d suggest starting with a smaller, more precise 1/4” torque wrench for the smaller bolts that need a good, accurate setting, then get a “general” 3/8” one that will cover most fasteners. After you have those, then get a larger, 1/2” one and you’ll be covered on all levels. Be sure to store them without any pressure on the internal spring so at a zero setting and they’ll stay accurate much longer.

My personal torque wrench setup is an SK Tools 1/4”, a Craftsman lighter-setting 3/8”, a general Harbor Freight 3/8” (most fasteners have a 10% tolerance, and HF wrenches are usually within 7% of settings, this one tested at under 4%), and a 1/2” beam-type Craftsman. Again, more accurate and better quality the more precise I need to be.

BTW, I don’t normally use a torque wrench for rear axles, it needs to be damn-tight. So to answer your question, I’d personally hesitate to use a 28Nm and up wrench on a 26Nm spec fastener.

Hope this helps!!!
 

Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
I've got calibrated wrenches from Silverline or Draper (from amazon) in the 3 drive sizes MIke mentioned for the reasons MIke mentioned :)

My 1/2" wrench is only used for rear axle and rear sprocket bolts because so far, all the other settings are well within the 3/8" drive wrench's range.

J
 

baugustine

2014
CBR650F
Staff
May 21, 2016
Ventura, CA
Just an addendum to the good info above. I worked for Mac Tools for 3 years back in the 90s, we sold high-end torque wrenches. We recommended that once a year they were sent in to be calibrated. The biggest surprise I got from the experience was the calibration center recommended the 3/8” version we sold be set at 30 ft/lbs when stored in the case, as opposed to completely unloaded at 0. Got into lots of arguments with technicians over this, so just be advised.
 

Pete J

2017
CBR650F ABS
Nov 20, 2018
I think that Mike has given very valid advice.
I have a Teng 3892AG-E3 which covers the range 20-110 Nm. I also have a Teng 3892AG-E1 for the range 5-25 Nm. Both are 3/8 inch drive, and both came with calibration certificates. The drive size is irrelevant, because you can get converters to change in any direction between 1/4, 3/8 and 1/2 inch, and they cost little. What little I know was taught to me by my father, who was a Jaguar-trained mechanic. His mantra was that there was much more damage caused by things being over-tightened than there ever was by being under-tightened. I have tightened the rear wheel spindle to 98 Nm, and that was tighter than I would have gone, had I I been using a spanner. The -E3 is also suitable for the oil drain plug (30 Nm) and filter (26 Nm). Smaller, less critical bolts and screws, such as for the fairings and chain guard, I tighten using a spanner or socket wrench as necessary, because the specs seem too high to me, especially when screwing into aluminium alloy. So truth be told, I have not yet used the -E1. But it does look nice when I open the case. All shiny red!
 
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Kevin

2020
CBR650R ABS
Sep 21, 2020
Ontario, Canada
Riding Since
2004
I’m a mechanic and have snap on, Mac, gearwrench and SK torque wrenches and I tell my apprentice to get the Gearwrench, Unless buying a digital but that is only used for engine rebuilds when torquing to yield. Gearwrench are well priced and make a good product and carry a warranty. I check the calibration on all of mine once a year and usually every year I’ll have to send one sometimes two of them out for a recal. For what it’s worth I keep them stored in their cases at the lowest torque setting (NOT 0!).
 

Rafe

2019
CBR650R ABS
Oct 1, 2019
United Kingdom
For what it’s worth I keep them stored in their cases at the lowest torque setting (NOT 0!).
That's interesting to know. I haven't had my torque wrenches very long and read slackening them off while in storage was the thing to do. I shall make that change based on your recommendation.
 

Kevin

2020
CBR650R ABS
Sep 21, 2020
Ontario, Canada
Riding Since
2004
Take the load off but never go below the lowest rating (eg. a 50-250 ft/lb torque wrench should be stored at 50 ft/lb).

An old vendor of mine used to work in industrial torquing and he was the one who educated me on it and I’ve never had an issue.
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
An old vendor of mine used to work in industrial torquing and he was the one who educated me on it and I’ve never had an issue.
Interesting. As I said, my dad handled all mechanical calibrations for a major manufacturer for over 20 years, and spent a lot of time talking to companies such as SK, MAC, Snap On, etc. about how to properly care for their products and keep them calibrated the longest. I go by his recommendations, and have never had an issue either.
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Can the axle bolt be managed with a 3/8" drive, or do you need a 1/2?
As Brammers @Brammers said your difficulty will be finding a 3/8” torque wrench with that high of a setting, and if you do it will probably not go very low so will be kind of a limited use device. That’s why I suggest you plan for 2 or 3 wrenches, not just because of the size drive, there are adaptors that can adjust that, but because of their useable range.
 

RedLeader

2020
CB650R ABS
Aug 10, 2020
Riding Since
2007
3/8" that go to 100 ft-lbs seem reasonably easy to find. I've seen ones with ranges as wide as 20-100 ft-lbs but they only claim stated accuracy in the upper 80% of the range.
 

Dankotaru

2019
CBR650R ABS
Jul 5, 2019
7000' ASL, USA
I've got some 20-25 year old Craftsman USA click types in 1/4 and 3/8 drive, and a calibrated CDI 1/2 drive that I typically use for lugs and whatnot, but I get it checked before I work on anything really sensitive to torque, like heads. I also have a digital torque angle gauge for TTA bolts and studs.

Interesting discussion about the different storage techniques. My dad was an aircraft mechanic for many years, and taught me to store clicker wrenches at 0. So, that's what I do out of habit, but some of the machinery techs I've worked with said they were told by Proto and CDI to just store it in the lower 1/3 of the certified range.
 
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