Face it, triathlon training is a gear-intensive pursuit, so just head on over to the bike shop with your credit card handy. Number one on your list is the helmet, and chisel the following in stone if you have to, but don't forget it: never, ever, ride without your helmet.
If you head out for a ride and find you left your helmet at home, turn around and go back for it or cancel the ride. Obviously, the key issue is safety, but your triathlon will require you to wear a helmet during the race, so you might as well get used to it. Always ride with a helmet.
The triathlon rules about helmet wear are so strict that you will be disqualified if an official sees you with so much as a loose chin strap. Triathlon organizers take safety very seriously. So should you.
An adequate helmet will set you back about $50. Used helmets are available, but be careful. Before you buy, check inside to make sure the foam isn't cracked. If it is, the helmet will not provide protection in the event of a spill.
Next on your shopping list is a good pair of bike shorts. They come with padding in just the right place to stave off major discomfort that you would inevitably feel from the pressure on the sit-bones of your backside. Don't skimp on this item.
Also consider a good riding jersey. Most come in very bright colors and wild designs, no doubt in part to make it easier for drivers of cars and trucks to see cyclists, but jerseys have another important function. Bike shorts don't have pockets, so where are you supposed to keep your identification (always take that), a bit of cash, or whatever else you might want to carry? Most riding jerseys have a zippered pocket in the back with plenty of room for your driver's license, some folding money, and a cell phone.
Hand in Glove
Riding gloves are also important. They, too, are padded. Remember that you will be leaning forward on your bicycle as you ride, and there will be a lot of pressure on the palms of your hands. The padding in the gloves can help with that.
The gloves will also come in handy should you crash. If you topple over, your natural tendency as you hit the ground will be to put out your hands to take the fall. The gloves will protect your hands from cuts and scrapes.
If you ride enough, and you will be doing lots of it in your triathlon training, you will eventually get a flat. Spend about $30 for a flat change kit. You will also need oil for your bike's chain, and don't forget the lights for riding at dusk, dawn, or even in the dark. Some states require lights for bicycle use after the sun has gone down. Lights in the rear should be red, and they should flash. In front, the light is used to help you see where you are going.