Because of it is not always possible to call for assistance there are several tools that should always be carried with one while bicycling.
Bicycling is a popular means of exercise and recreation. But because the bicycle is a mechanical device there are many small accidents that can occur to put one’s bicycle out of service. With a little foresight, the prepared rider can repair these on the road, and be able to get home without having to find some way to call for help.
In broad terms the kinds of things to put your bicycle out of service come in three general categories.
First, and easiest to fix, are the cases where something has gone out of alignment: the handlebars, the seat, the brake calipers, or the derailers. If something has gone out of alignment it’s usually easy enough to realign, but without proper tools it is difficult to be sure that they will stay realigned. And riding a bicycle without handlebars that can be trusted to stay in the proper alignment is foolhardy. Fortunately, the tension clamps for the seat and handlebars are usually tightened by a nut. Carrying a suitable wrench is easy enough. Many bike manufacturers have put a little thought to user servicing, as well, so that the only nuts that the rider will likely have to adjust during a ride are all the same size. Check your bicycle, if your tension clamps are tightened by, say, a 9/16 wrench it’s better on your nuts to carry one (or two) non-adjustable wrench that fits the nuts you may need to adjust. Adjustable wrenches are very useful, of course, but they have a distressing tendency to strip nuts as well. And clamp-lock wrenches add compression distortion to that.
To adjust tension on your brake calipers and derailers you’ll need a smallish screwdriver. Again, most bicycle manufacturers now use only one standard kind of screw for the adjustment screws now, so you’ll only need one screwdriver for all your adjustment screws. Check your adjustment screws and your technical manual’s recommendations for a proper sized screwdriver.
The second kind of problem is flat tires. To fix these you need to carry a spare inner tube with you, and have a hand pump on your bike. The advent of the small hand pumps that clip onto bikes make this an easy requirement to carry, with little extra mass. And the spare inner tube is not much more weight. Getting the tire back on over the new inner tube can be a challenge but patience and a little effort it can be done in the field.
Finally, the third kind of problem is structural damage: warped or broken wheel spokes, warped wheels, and bent frames are all out of the ability of the rider to fix with small and simple tools. So, there’s no point in trying to carry tools to deal with those eventualities.
So, to reiterate, a mobile repair kit for your bicycle should contain the following:
- One or two wrenches, sized for the nuts on your bike. Preferably box wrenches, not adjustable ones.
- One screwdriver suitable for making adjustments to your set screws.
- A spare inner tube for your bike’s tires.
- A hand air pump.
- An air gauge, to check pressure in your tires.
- Spare batteries and bulbs for your lights.
You may find other items useful, but this is a good beginning kit.