Everyone should have a mini tool with them when they are out riding, as it's easy to find something has come loose or you want to adjust something on the bike. We have been using this Topeak Mini 20 Pro tool for around 3 years, so here's a brief review of it.
With tools that you either have to keep on your person, in your bag or on your bike there is always a balance between having enough tools on them that cover every common eventuality, but not being so big and heavy you end up not bothering carrying it. The Mini 20 Pro comes in a nice tidy neoprene bag and is slim, small and light at only 150g. This means its easy to strap onto a frame or keep in a short pocket and you don't notice it's there.
For such a small tool, it really packs in the features:
Chain breaker tool
Allen keys : 2-L / 2.5 / 3 / 4 / 5 / 6 / 8 / 10 mm
Torx : T10 / T25
These cover most things that you'd need to adjust on most parts of the bike, including stem/bars , brake levers, shock/fork setting and pedals/cranks. We've not really come across an occasion where the tool didn't have what we needed when out and about, with one exception.
The tyre level is REALLY small and not shaped quite as well as other levers we've used. For an emergency it might possibly do the job, but if we are going out on a big day in the alps we always carry a separate dedicated large lever with a tube.
The chain breaker works well, and whilst it does need a little more force to use than a bigger tool, does the job.
We've had this tool now for a long time, and it's done many many thousands of miles with us. It's been strapped to the bike and got soaking wet and covered in mud on more occasions than we can think of and aside from a few spots of surface rust the Topeak is working as well as the day we got it. With cheaper tools the allen keys can start to round off, but these have all remained true.
At around £30 (although you can find it cheaper), the Topeak Mini 20 Pro is pretty expensive for a mini tool. It's not hard to find tools of a similar size for under a tenner, and we've even bought one from Tesco for £3.99 before. Unlike the cheap ones though, the tools haven't rounded off or broken and Topeak is of a much higher standard than others we've used. Personally we'd rather buy something like this once and then not have to think about it again for years and years, the quality combined with the micro size and weight means the Mini 20 Pro gets a big thumbs up from us.