4

I'm looking for advice on the range of torque, bit pieces and any other features I might need for smaller to medium sized jobs.

From what I read I'd need a separate wrench for the bigger jobs like bottom bracket. I'm not sure about pedals: I'm running Shimano M520 and I haven't seen them installed with a torque-adjustable wrench before, just a pedal tool. Would a non-calibrated pedal tool be alright for installation + removal?

I'd like to be able to work on things like handlebars, headset, derailleurs, crankset, brakes, shifters, racks, seatpost, & similar sized jobs.

The only carbon parts are the forks and the seat post. The largest hex bolt I've found so far is 5mm. The bike is a 2019 Fastroad SL-1, details are here https://www.giant-bicycles.com/au/fastroad-sl-1-2019

Some examples of specs for reasonably priced wrenches that I've found so far are:

  • 2-15nm adjustable torque click type, Hex: 2/2.5/3/4/5/6mm, Torx: T10, T25, T30, one-way torque
  • 2-24nm adjustable torque click type, Hex: 3/4/5/6/8/10mm Torx: T20, T25 & T30, one-way torque

I'm leaning toward something click-type in the 2-15nm range: The bits seem to be more suited to bike component size, and I don't think any of the jobs that I could be doing with Hex / Torx ends require more than 15nm. I'm having a bit of trouble finding confirmation on that for all components though.

Some other considerations I'd like to nail down are:

  • Do I need two-direction measured torque for any of these jobs? Pedals probably won't be handled by this size wrench I'm guessing, BB seems way off.
  • Would a beam style wrench be just as good, or more suitable than a click-type?
  • Am I overlooking any bit adapters that I might need?
  • Do I actually need two wrenches for all the jobs I'd like to handle?
  • Am I overthinking things and will be fine without a calibrated tool?
  • 1
    Maybe not now, but your next bike may easily require larger than 5 mm bolts. Mine has 8mm 10 Nm one for the rear thru axle. At least at home I try to go with a torque wrench. Outside by feel, so I normally end up using much less. Theoretically also an 8mm 33Nm for the pedals, but I do not really have a torque wrench for that. I have to go by feel. – Vladimir F Mar 12 at 19:57
  • 1
    You don't need one capable of both directions. Pedals are the only ordinary situation you'd want a left-turning torque wrench, but in that situation "hella tight" is accurate enough, and you're not likely to overtighten unless you do something really elaborate. – whatsisname Mar 12 at 20:07
  • Only ever use my 2-20Nm on the bike, hardly ever over 10Nm. My bigger torque wrench (used for car maintenance) came out a couple of times but the novelty for using a torque wrench on the 'big bolts" wore off - "Good'n'tight' without being a Gorrilla with the spanner works fine. – mattnz Mar 13 at 4:11
  • @VladimirF what's the torque range on your bike wrench, and can you feel the clicks easily at lower torque settings? A reviewer of the 2-24nm wrench that came with 8/10mm bits said it was a bit hard to feel the clicks at the lower end of the torque range. – Scottmeup Mar 14 at 16:36
  • I have the beam type. Aren't the bits the standard size? You should be able to use any other standard bits swith your wrench if it is not something special. – Vladimir F Mar 14 at 16:57
3

I have only a 2-24 Nm click type torque wrench and coincidentally the main job I typically use it for is the pinch bolts on cranks, but also when attaching carbon parts like bars, less frequently. The 12-14 Nm required for Shimano pinch bolts is right in the middle of the tool's range and that gives me a warm feeling inside.

Of course carbon parts require care and having a torque wrench is useful. They will not require high torque values so either tool you have listed (2-15, 2-24) would be suitable.

For other jobs though I try to make it a habit of developing a feel for the tools that I use and what torque means. For example someone v experienced suggested to me that when using the Park Tool AWS-10, the tool will 'flex' in the hand just slightly when the right kind of torque is reached, for a lot of bolts in common usage. I would rather build up experience in using tools in this kind of way than inadvertently become reliant on torque wrenches.

You could look up torque values for various bicycle components, and note what range they fall in. Notice that for a given size of hex wrench, there will be a 'ceiling' value. eg you wouldn't normally exceed ~8 Nm for a 5 mm Allen bolt. Then you can adjust your thinking to the size of the bolt and turn the lever accordingly. Crank pinch bolts are an obvious exception - use the tool carefully to avoid rounding the bolt.

For high torques like 40 Nm, I have previously used a large torque wrench about 40cm long, and found that I still need to pull quite hard on the lever to achieve 40 Nm. So if I am using a tool that long, or shorter, I don't worry about over tightening! Nice and tight. You could borrow a tool like this to see how tight 40 Nm is for your own strength.

Don't worry about two way torque, you shouldn't need it. Even for left hand threaded parts, you could measure the torque on the RH one, then use your muscle memory to approximate this on the LH part (pedals, bb's).

So I would say, yes get one of those, selected best to suit how you think you'll use it in your own situation. If you're missing bits etc then you can add these later, it's not the end of the world. Then learn when you need to use it, but also try and find situations where you don't need to depend on it.

| improve this answer | |
  • Agree on the two way torque issue. I would argue that unless we are talking about power meter pedals, many riders should be able to hand tighten their pedals and leave them be - they will tend to thread themselves in even if not tight enough. For threaded bottom brackets on a relatively inexpensive frame, one could also just tighten by hand, keeping in mind you need to really tighten them hard. Alternatively, leave the BB to the shop. The OP didn’t list the BB as a use case anyway. – Weiwen Ng Mar 12 at 14:38
  • @WeiwenNg good points. I would always tighten pedals nice and tight with a good length lever. They should self tighten but we see a lot of damaged cranks where the pedal wasn't tight enough and destroyed the crank – Swifty Mar 12 at 14:41
  • The BB is normally done by a non-torque wrench like Park Tool BBT-9. I haven't seen an amature-level Hollowtech II torque wrench. I would be even worried whether a typical small bikeshop uses anything better although BBT-59.2 is not expensive at all. – Vladimir F Mar 12 at 20:02
  • Do you have any trouble feeling the clicks at the lower range of the torque settings? I think 6nm max is the lowest max torque rated bolt I've come across so far, I think if I can feel the 5nm setting that would be good. – Scottmeup Mar 14 at 16:41
4

Would a beam style wrench be just as good, or more suitable than a click-type?

Definitely not. With a beam-style wrench you have to accurately observe where the pointer is on the scale. That means you have to be looking straight-on at the scale. Bicycle bolts are at all angle and orientations, which means looking at the scale will be very awkward.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.