To fix a flat you will need a 15 mm wrench, patches and tire irons. I have heard you can pull the tube without taking the wheel off, but i have never done that and that requires you know where the puncture is. Sometimes in the rain or snow it is easier to find the thorn or glass sticking through the tire,remove that and just use a new tube, fixing the bad one at home. I have,especially when trying out different handlebars or new brakes, found it good to be able to adjust those things with an allen wrench. I have also had a quiklink fail about ten miles out and it was nice to have another. However, where I live there is no public transportation, so the option of getting to the destination that way is not available.