Torque keys. Not the most exciting thing, but probably the most useful tool I own.
Almost every bolt on your handlebar attachments (brake levers, gears, dropper remote), stem & actually most bolts on your bike need tightening to 5nm. This is very important on handlebars, where over tightening can crush & damage the handlebars. So in comes this little gadget – I use the Ritchey one, but others are available 😉 comes with every bit you'll need (Allen keys & torx) and is preset to 5nm – just tighten till it clicks & you know you've done it right 😊
