Tyre leavers x2	Some people suggest three, I find two is good enough. You can find these really cheap on eBay but if you fancy spending a few pounds the Motion pro tyre levers are very good, very light weight and double up as spanners.	Essential
Sockets that fit your bike - (6mm, 8mm, 9mm, 10mm, 11mm, 12mm, 14mm, 27mm)	The ones people often overlook are the wheel nuts. Double check these. For example, KTM tends to use a 27mm front and rear, but Yamaha can use 27mm front and 22mm rear.  A great little tool for sockets is the MotionPro Trail tool, which has most of those sockets in it and doubles up as a screwdriver. If not, the small 3/8" kits often have a good combination that you can get what you need from.	Essential
Wrench (or alternative to drive your sockets)	Something as small and light as you can get. I have a small adaptor that changes one of my tyre levers into a 3/8" wrench and the Trail Tool has both 1/4" and 3/8" drives.	Essential
Hex/Allen Keys that fit your bike	You can use any allen keys as long as they fit and they are often small enough to easily fit into any pack. One to watch out for is that some bikes have a large allen key to remove the front wheel, check yours. E.g. 14mm on XTZ. I use my Trail Tool for this job.	Essential
Screwdriver	It's a screwdriver, what more can I say. I again use the Trail Tool for this job.	Essential
Multitool (Pliers and knife could be used instead)	Lots of people highly recommend these but to be honest, mine only gets used as a glorified set of pliers and a knife. None the less, plies and a knife are both useful and the multi tools pack down well.	Essential
Small adjustable spanner	There are simply places that sockets don't reach and this is the ideal option for adjusting those nuts and bolts.	Essential
Sparkplug socket	Make sure you get one that fits your wrench, or you have a way to drive it.	Essential
Bike pump	Something small enough to go in your kit bag. I use a small Moskito pump with a gas canister assist, it isn't the best pump in the world but it works and it is small.	Essential
Tyre valve repairer/remover	Small tool that can re-seat and re-thread a damaged tyre valve. I bought it as a valve remover and the other bits were a bonus. Tip: if you have to take your tyre off, it's easier to take the valve out to push out any remaining air. Tyres can often stop going down when the pressure out and leave you battling against it.	Recommended
Valve puller	A tiny little tool that make easy work of threading your valve through your rim. I know, sounds like it should be a simple task. But try it in the cold and damp at the side of a trail, all the help you can get is good.	Recommended
Chain breaker	If your chain snaps this is what you'll need to get the broken link out.	Recommended
Towing strap	Might get you out of a pickle if all else fails. I've only had to use one to bump start a larger bike, but I was glad one of the lads had one when I needed it.	Recommended
Jump leads	Many trails bikes have kick starts but there are increasing numbers of people taking larger adventure class bikes off road for an explore. You will likely find that especially when learning the ropes you will stop and start more often which can take it out of your battery. If that happens, these will help. You can buy motorcycle/scooter leads quite cheap on eBay.	Tip
Third leg	More for the adventure bikes. If your bike doesn't have a centre stand these can be useful. The work with your side stand to lift the front or back wheel off the ground.	Tip
Tyre pressure gauge	Depending on what pump you use, you may have one. I carry a small simple pen type gauge with me to quickly check pressures.	Tip

So you have the tool kit, but what else comes in handy?

21" front tube or one to fit your bike.	You can get away with using a 21" front in your rear so no need for two if you do it this way.	Recommended
Puncture repair kit	If you're unlucky enough to have two punctures you'll need this.	Essential
Zip/Cable ties	These things can get you around a multitude of problems.	Recommended
Spare spark plug	Not something that I have ever needed to date but they can fail and this is something that is small and easy enough to carry.	Recommended
Electrical tape	Small roll and will double up for other tape duties in a 'sticky' situation. Sorry, I'll get my coat.	Recommended
Spare fuses	Just make sure they fit your bike.	Recommended
Radweld or Ce-lit	If you suffer from a broken radiator this will fix it to get you home.	Recommended
Chemical Metal	Incredible stuff this, mix it together into a putty and use to to repair all manner of things including engine cases. We've used this to fix a water pump housing with great success.	Recommended
Split link	If you've used your chain breaker, you'll need one of these to put your chain back together.	Recommended
Some threads of wire	You never know.	Recommended
First aid kit	This one can be a bit of a how long is a piece of string, but some basics like plasters can come in handy. It might not be for anything serious, you may simply slip with a spanner and cut your hand.	Recommended
Surgical gloves	Stuff some in your bag to save your hands getting dirty when working on the bike. (I've been meaning to get around to this one for sometime myself)	Tip

Not everyone has the spare cash lying around to go out and buy all of this stuff but many of us have a lot of this gear hanging around in a toolbox somewhere. So to get you started, go and have a rummage. Lots of people have a little 1/4" socket set that is often not used in favour of a larger 1/2" set, raid the little one for bits. Don't have a spare adjustable spanner, use the one you have, you can always go and get it off the bike when you need it.

However, if you are buying new tools, there is a handy rule to keep in mind. Make sure everything you put in your bag has more than one use. E.g. My trail tool = sockets, screwdriver, allen keys. Tyre levers are spanners also. Multi tool = knife and pliers. This will help you keep weight down and save space.

However, even without the latest space saving tools, you'd be surprised how much you can fit in a small bag. Don't forget, your bike has lots of places to strap smaller bags with bits and pieces in it, for example: under your seat, strapped to the bar pad, strapped to your seat. Many people stick things in a backpack or hydration pack but I personally don't like this, as I don't like the idea of falling off and landing on my tools (I don't like the idea of falling off either). 

My personal favourite combination for carrying things:

• Tail pack carrying my tools and a spare tube, I presently use a Kriega US10 which is a little large for the job but on cold days has enough room for me to stuff a spare fleece and a dry pair of gloves. 
• Hydration pack holds my water (obviously), small plastic bag with puncture kit, tubes of stuff, little bits and bobs and the every important... Snickers and a couple of packets of Haribo.  

Depending on who you ride with, there is a good chance you can spread this kit around. However, I like the peace of mind in knowing I have what I need to sort it out. I still think I have a few too many bits with me, but something niggles me that I'll need them so they stay in there. One day I'll probably conclude I don't need them.

Recommendations

I've mentioned a few brands in the article above. These are only personal recommendations but you may find them useful.

I really rate all of Kriega's gear and I have yet to find anyone with a bad word to say about them. Why do I rate them? Thekit is just really well thought out. The strapping system makes them easy to remove and you can also attach them to other Kriega gear like their larger packs and backpacks to make combo bags. There are extremely water tight as I found out first hand dropping my bike in a river with my phone in one. The Kriega US5 is a great little bag for strapping your tools to your bike.

Motion Pro Trail Tool

      

As with the Kriega gear, I like the Motion Pro stuff because it is innovative and most importantly works well. Furthermore the build quality is second to none. I debated the trail tool for a long time before getting one, but when I finally did I have to admit it is money well spent. 

Very compact when packed away. When assembled it provides a full length screw and allan driver. Alternatively, you can flip the end 90 degrees which allows you to get some real leverage on tuff to budge screws. Then there is the 3/8" socket driver, which combined with the sockets supplied and a couple of supplements makes for a very nice to use socket set. You can also flip the socket attachment to change it to a 1/4" socket, useful if you have a couple of small sockets hanging around. And finally, you've got to rate a company that remembers to put the ever important bottle opener on a tool!  

Motion Pro Combo Levers

For long enough I got by without my own set of levers and eventually I decided enough was enough and I needed to get myself some for my own kit bag. The levers were recommended to me by a number of people so I took the plunge. When you first open them your reaction will be towards the weight, these are so light it is quite unbelievable that they would ever be strong enough to change a tyre. But when using them, they don't flex an inch. I bought one with the small spanner, this is actually a 12mm on one side and 13mm on the other. It's actually nice and handy for removing the valve nut, especially as you have them out anyway. The 12/13 Combo also has a little lip on the tyre lever end which does seem to help grab the tyre for those first couple of lever pulls. My second is a 22mm which I bought because the bike I used at the time had a 22mm rear nut. Complimenting these, I also added their 3/8" socket adaptor which provides you with a nice long lever for removing wheel nuts. I may still yet buy a 3rd leaver, if I do, would get another one of these with a 27mm spanner to fit my current bike which will let me ditch the quite heavy 27mm socket I carry.