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An orbea carbon road bike has 20Nm marked on both front and rear thru axles (6mm hex) for the wheels. This is fine in most cases, however impossible to remove with a multitool when getting a puncture out on the road. The only solution I can see for this is to carry a large Allen key, but it is quite unfeasible and doesn't seem right. Most other bikes I have worked on have 10Nm 6mm hex thu axle.

My question is, do you think leaving them at 10Nm would be suitable? Which would then enable removing the wheel a lot more feasible on the road.

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    This is really a lot of torque. The only one who could approve tightening less is the manufacturer. If the number were just an unexceedable maximum, instead of a target value. I must admit I do not use a torque wrench when unmounting my rear TA. And the front one is operated by a handle so the torq wrench cannot even be attached at all. However, they state only some 10 N.m.
    – Vladimir F Героям слава
    Aug 1, 2021 at 10:49
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    What’s the thread pitch? Even the ultra-coarse M12x1.75mm on my MTB has a torque rating of only 10-12Nm. Not sure why yours would need much more.
    – MaplePanda
    Aug 1, 2021 at 16:32
  • +1 to Vladimir F. My torque wrench only goes as high as 20 Nm, and has a handle of about 40 cm long. Some multitools are more ergonomic than others, fwiw.
    – Adam Rice
    Aug 1, 2021 at 19:14
  • 20 nm is too much if I recall it correctly, I have the same bike and I can easily get the axle in and out with a multi tool. I will check the required torque in the manual when I get home.
    – Odyssee
    Aug 4, 2021 at 9:46
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    I glanced at torque specs for thru axles in general, and a bunch of Google hits are more in the 10-12 Nm range. So yes, 20 Nm seems like it is higher than average, and it is quite a lot of torque. So, on one hand, the manufacturer put that recommendation there - did they actually test and find that actually, this bike really needs 20 Nm? Or are they being too conservative?
    – Weiwen Ng
    Aug 5, 2021 at 13:26

3 Answers 3

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If the marking says 20 newton metres, then that's what the manufacturer has resolved as the correct torque. If you're looking for permission to undertighten your through-axle, then that's your personal decision.

Instead, consider getting a single longer 6mm hex tool and stowing that with your spare tube on the bike. If weight is an issue, trim off unnecessary bits, or look for a titanium tool.

There also might be multitools that provide more leverage, by folding out tools at the opposite end of the 6mm bit to give you more length thus leverage.

Lastly, adding a short length of pipe as a cheater bar to your toolkit could also provide that leverage. Light aluminium or even plastic PVC pipe can be sufficient, and it probably doesn't need to be more than 15~20 cm long.

I suggest you get/borrow a torque wrench and tighten this bolt to 20 Nm. Then use your hand tool to make sure it can be undone and done up again. You're trying to get a muscle-memory for how tight the bolt has to be.

You might be surprised how much or how little effort it takes - getting a "well calibrated elbow" is a useful skill.

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    I've just put a 'long' 6mm hex key on the scales: It weighs 42g and is 14cm long, quite easy to stow in a saddle pouch.
    – Carel
    Aug 1, 2021 at 7:05
  • 40g for a 6mm Birzman hex key, also 14cm length. Add the 4mm and 2.5mm hex keys and you are at 56g for a full set of tools.
    – Michael
    Aug 1, 2021 at 8:45
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    @Carel 14 cm does not fit into any of my saddle bags.
    – Vladimir F Героям слава
    Aug 1, 2021 at 10:50
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    @VladimirF: Just tape it to the frame then …
    – Michael
    Aug 1, 2021 at 13:55
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    @VladimirF : Or get a different saddle bag!
    – Carel
    Aug 1, 2021 at 20:22
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Lack of torque/leverage when operating a multitool in field conditions is typical for the situation when loosening/tightening the pedals, not the wheels.

Ironically, an extracted through-axle can be used as such a lever when attached to the multitool:

Axle as lever

Image source

In your situation, it is only applicable if you've managed to unscrew at least one of the through axles. It does not have to come from the same bicycle if you are traveling with someone else.

In general, your travel toolbox should suite your requirements, as no multitool is truly universal. Some multitools are just larger than others, so getting a bigger one is one way.

Adding a separate long 6 mm key to your toolbox is the easiest solution, I think. I do carry such a key when I know in advance that I'll be taking the pedals off and on.

If you have nowhere to put it, tape it to your pump, or to the frame. You do carry a pump with you, right?

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    When performing roadside repairs imagination and lateral thinking are two very important factors for success.
    – Carel
    Aug 1, 2021 at 20:28
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    heh I was looking at image, wondering how you get the crank off to get the through-axle out of the fork.
    – Criggie ♦
    Aug 2, 2021 at 1:11
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I heavily recommend not carrying a multitool, but rather a set of shortish Allen and Torx keys that are the exact sizes that you need for your bike.

I have weighed a number of multitools and found that usually they are not only more cumbersome to use than individual Allen/Torx keys, but also often surprisingly heavy as well. I don't believe I have any weight penalty by choosing to carry individual keys. Of course carrying the longest keys I can find would have a weight penalty, but I choose to carry short keys instead.

The only "multitool" I carry (if it can be called as such) is a chain breaker that happens to have cut-outs that can be used as a spoke wrench. The chain breaker is operated by an external Allen key.

Here's a list of what I carry. My 6mm Allen key only weighs 29 grams. The full set of Allen keys (including 8mm which you may not need, 56 grams), two Torx keys, a Philips/slotted wrench and chaintool-spokewrench weighs 220 grams. The weight of a typical multitool having the same is around 200 grams, and doesn't give you enough leverage on the largest sized Allen keys as you have found. Plus, with a multitool you are forced to use what the multitool manufacturer has decided to give you, whereas with individual tools you choose what you carry. One example of a multitool (Crankbrothers M20) weighs 203 grams and lacks T30 Torx key (17 grams to carry the T30 key separately), so not really a single gram saved.

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  • A multitool does not just come with some weight saving, but with even more important weight saving. A typical saddle bag is hard to fit with the necessary safety equipment and two spare tubes are often already impossible (if not small road-bike ones). A set of individual tools will require a larger bag while a multitool fits into the jersey pocket if necessary. That way, each bike can have its multitool permanently stowed in a small saddle bag.
    – Vladimir F Героям слава
    Aug 1, 2021 at 10:11
  • @VladimirF: 3 hex keys + tire levers + road bike tube + patches should fit into any saddle bag. Otherwise what is the bag for? Just your door keys?
    – Michael
    Aug 1, 2021 at 13:57
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    I don’t know why everyone is so worried about weight saving ? The heaviest thing on my bike is the water bottle when full, most of you wouldn’t notice the difference an extra hex key makes. There’s really no reason not to carry one.
    – Dan K
    Aug 1, 2021 at 15:31
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    I know people who carry individual hex keys instead of a multitool. I myself do that on one of bikes whenever I do not plan to wander too far away from home. Individual hex keys, besides being light and more configurable, are also more ergonomic to use (trying to stick a bulky multitool under the seatpost head to tighten the saddle is pain)
    – Grigory Rechistov
    Aug 1, 2021 at 15:52
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    @DanK: Please not the discussion about weight again. Of course you wouldn’t notice a single hex key, but it all adds up.
    – Michael
    Aug 2, 2021 at 7:21

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