A multi-tool is a small and compact collection of tools that allow you to work on your bike when you’re on the go. They range in size from the simplest collection of Allen keys to those that include almost everything you’ll need to work on your bike. Usually, more tools mean more weight, but you'll be glad you have what you need for every eventuality.
What to Look For
The classic Swiss army knife style is most popular as it keeps all the tools neatly together without the need for an extra case. Socket set style tools are handy for those hard-to-reach bolts. Tools designed to fit in your steerer tube, chainset or handlebar ends mean that they’re easy to reach and you don’t have to keep them in a pocket or bag.
Each multitool will have a different combination of tools and the best one for you will depend on your bike and the type of cycling you do.
Basic Tools
These are the tools that every cyclist is likely to find useful.
Allen Keys / Hex Keys
Most bike components can be tightened or undone with a 4mm or 5mm Allen key, so these are essential for every multi-tool. Smaller 3mm, 2.5mm and 2mm keys are useful for smaller adjustments on brakes and drivetrains and a 6mm can be handy too. Larger 8mm or 10mm bits often aren’t much use as the tool doesn’t have enough leverage to loosen bolts that size.
Look for chamfered tips, these are a sign of quality and help prevent the rounding of bolts and the keys. Removable Allen keys can be useful for reaching those small hard to get to bolts like brake reach adjusters.
Torx Keys
Torx bolts are becoming increasingly common on bikes especially those with disc brakes. T20 and T25 bits are most common, but some brands use Torx bolts instead of Allen bolts on components like stems and seat clamps. If you have a Scott or Bergamont bike, then you will need a larger T30 and maybe a smaller T10 bit.
Screwdriver bits
A Crosshead screwdriver is useful for adjusting derailleur stops and brake tension springs. Most tools also include a flat head screwdriver. While most modern bikes don’t have any flat head screw this can always be used for prising things apart.
Chain Tool
If you’ve ever snapped a chain mid-ride or tangled it behind the cassette, you’ll know how handy a chain splitter tool can be. If you also carry a spare split link – some multi-tools have space to carry these – then you be back up and pedalling in a matter of minutes. Chain hooks are useful, especially if you don’t have a derailleur with a cage lock, as they help to keep the chain in place while you work.
Tyre Levers
Unless you are a time served bike mechanic with hands like a gorilla then you’ll need tyre levers to fix a puncture in your inner tube. Most cyclists tend to carry separate tyre levers with a spare tube and/or puncture repair kit but getting a multitool with tyre levers included means you have one less thing to carry.
Specialist tools
While you might not need these tools as often as the ones above, they may be the tools that save your day when you’re out on a big ride.
Spoke keys
If you bend your wheel riding over a pothole mid ride or buckle it in a crash, then you’ll be glad you’ve got spoke keys to help you get your wheel back into shape. These are often incorporated into the chain splitter or one of the other keys, so they don’t add much in the way of weight.
Valve core remover
If you’re running tubeless tyres, then your valve is likely to get blocked up with sealant at some point making it difficult to pump the tyre up. A valve core remover is helpful as it is easy to unblock the valve once it’s removed. Like spoke keys valve core removers are small and can easily be incorporated into other tools.
Tyre plugs
Puncture in tubeless tyres can be fixed by inserting a plug into the hole. This is easy to do and works very effectively, as you don’t need to remove the wheel or tyre. Some multi-tools include tyre plugs and an insertion tool so you don’t need to carry a separate tubeless tyre puncture repair kit.
Other tools
If you’ve ever tried to remove a split link from a well-used chain by hand you’ll appreciate how useful a small set of pliers can be. Pliers are also very useful for loosening stubborn valve screws. A disc brake pad spreader tool is useful when changing brake pads. Most adult bikes don’t have bolts with nuts, but spanners can be useful for kids’ bikes.