Which bike multitool should I get for a cannondale trail 3 2019? Which other tools will I need?

Check what type of fasteners you have on your bike. Usually its bolts with allen key heads or torx heads. Most multitools have both but you could choose only allen/torx after you've checked that your bike only has 1 of the 2.

From some brief googling it looks to me like you have (mostly) allen head bolts (six sided).

here's a comparison of what they look like :

A flathead and philips heads screwdriver will also be very useful (for derailleur adjustment for example).

Some multitools come with a built in chain tool, which I find is a must. If you don't get a multitool with this built in you could always take a seperate chain tool but there will be more bulk and weight.

For 20-30 euro you should definitely be able to get a multitool that meets all these requirements, probably you can find it cheaper if you look around a bit.

Here is the multitool I'm currently using. https://www.belgafietsen.nl/specialized-emt-12-minitool.html?gclid=EAIaIQobChMIt8O-4N7u5wIVUud3Ch2pgAZqEAQYBiABEgLIZfD_BwE

a similar alternative: https://www.internet-bikes.com/195523-sigma-multitool-pocket-tool-medium-16-functies-zwart/?tt=10107_12_290797&gclid=EAIaIQobChMIt8O-4N7u5wIVUud3Ch2pgAZqEAQYBSABEgIxO_D_BwE

One more thing to check is the length of the multitool itself since when you're using it and you've got one of the tools extended you're using the body of the multitool as leverage so the longer it is the better (in terms of leverage).

I wouldn’t get a multi tool.

All the tools you need for a modern bicycle (if you are not replacing bearings, crankset or cassette) are:

• 4mm hex key for:
  • seat post clamp
  • stem+handlebars
  • bottle holders
  • racks
• 5mm hex key for:
  • rim brakes brake lever clamps
  • derailleurs
  • saddle rail clamps
• T25 torx for:
  • disc brake rotors
• 8mm hex key for:
  • pedals
• screwdriver for:
  • derailleur limit screws
• spoke key for wheel spokes
• tire levers
• pump
• chain tool

Get a set of proper hex keys and the T25 torx if you have disc brakes. Get tire levers, a small pump for the ride and a large pump for the workshop.

But on single day rides it doesn’t make sense to bring any of keys. You really only need the small pump, tire levers and a spare tube.

When I’m making saddle adjustments I take a 4mm hex key (and maybe a 5mm key if I’m also adjusting the fore-aft position) for the ride.

On multi-day travel I bring the 4mm and 5mm keys plus spare shifter cables and spare bottle holder screws. I also bring the spoke key and spare spokes (only makes sense if you know how to use it). A multi tool would have too many tools on it (which makes it heavier than the two dedicated keys) and they are usually short and fiddly.

If you have disc brakes and need/want a T25 Torx key I’d get this T25 Torx bit from Topeak which turns a 4mm allen key into a fully functional T25 Torx key.

It's not a great idea to assemble the bike with a multitool. Multitools are short, which means you can't exert as much leverage as with a regular tool; and have a joint between the handle and tool heads, which means they are not as stiff. Multitools are a compromise to allow you to carry them while riding and be able to make adjustments if you need to. If you plan to do adjustments and servicing yourself, buy the proper tools. They will be far easier and effective to use. The list that Michael provided is a great start.

Do you need a multitool to carry with you on a ride? That's personal preference. A spare tube and a mini pump or CO2 inflater are probably more important.

In my experience it's difficult at best to find individual hex and torx wrenches. They all seem to come in sets, and when I can find an individual wrench it's usually really expensive compared to just buying a set.

For outfitting a new workbench/shop I'd definitely advise a set of individual wrenches. But for on a bike I prefer a multitool. Note that no multitool will fit everything as bicycles require a number of unique tools for things like bottom brackets.

My preference is for the Lezyne stainless steel multitools. The Stainless 20 will have everything you'll need for basic fixes. (Hex, Torx, screw drivers, chain tool)

The Crank Brothers M19 is similar in the collection of tools, but it is carbon steel that is harder and less likely to deform (round). But it'll rust and is a bit heavier than the Lezyne. The M19 has Torx T10 & T25 while the Lezyne only has the T25. The chain tool on the M19 is rated for 8 thru 12 speed while the Lezyne is only rated for 8-11 speed.

Your Cannondale dealer should be able to guide you through the complete list of bolt sizes on your new bike. Wheels for example may require a unique spoke wrench. You may be able to get a smaller tool and save a bit of $$$ and weight.

I own both the Lezyne and M19 and they've worked well when needed. Get a good quality tool and it'll never disappoint. Cheap tools generally fail at the worst possible time.

If the bike has been pre-assembled before shipping, there should be minimal work for you to do in the first instance. This should include turning the handlebars, attaching the pedals, adjusting the saddle and checking the tyres are inflated. You might also adjust the position of the controls (i.e. brake lever angle). These tasks require Allen keys in 4, 5, 6 mm, and either a 8 mm Allen key or 15 mm pedal spanner for the pedals, depending on your design - normally a 15 mm pedal spanner for included (basic) pedals.

So that's it, Allen keys, pedal spanner and pump. All of these Allen key sizes will be included on any multitool so you can choose freely, considering other advice and what maintenance you plan or expect to do. Other answers suggesting Torx keys and chain tools etc - these features will be useful at some point in the future and you should buy a quality, long-lasting tool when you do purchase one.

Remember that the left pedal is left hand threaded. Many new bike owners have had to head to the LBS for a repair or replacement of the left crank, reducing that mail order bargain effect. Do ensure the pedals are fixed tightly to the cranks.

You may find that the bike ships with a small Allen key multitool and pedal spanner, as some mail order bikes will come with these and instructions, you could contact the seller to ask or wait and see if it is included.