When I was young and poor I would wear whatever clothes I had while riding the bike. As I grew older and had more money I was resistant to change. The first thing I tried was the shoes. I tried thick rubber soled Bata Biker shoes. I liked them because they slid in and out of the toe clips without getting snagged. Later I got some beautiful Detto leather cycling shoes that had a sort of cleat that would keep your foot from sliding out off the back of the pedal. I loved the feel of the leather. I tried a pair of wool riding shorts and they didn't have a small enough size at the shop I went to. The guy at the shop said I would 'grow into' them as I rode more. I laughed. If I hadn't grown enough by 20 years of riding to fit the shorts, I would never grow enough. Finally after 35 or so, I tried some clothes that actually fit. There are advantages and disadvantages to the special clothing and I'm thinking mostly of the shirt/jersey. Typically the special clothing is a synthetic material that clings tightly to your body. They tend to cost upwards of $40 per item. Non-synthetic wool and leather (chamois) short portions options are vastly more expensive.

Advantages

• the pants don't get caught in the pedals/chain.
• the shirt doesn't flap in the wind at speed
• shirt pocket is handy and well-placed for carrying various things
• wool doesn't stink
• unzip the shirt/jersey all the way down your belly

Disadvantages

• expensive
• stench of synthetics
• they can be difficult to remove as you 'grow into them'
• wool must be washed carefully

I am much more partial to the shoes. I had graduated to clipless racing shoes and now SPD shoes I can almost walk comfortably in. These tend to be expensive for a single use type of shoe, but they are worth it in my book. On long rides your footwork gets sloppy and if you fall of the pedal it can be disastrous. On sportier rides the cleat allows for pulling up and pushing down and even allows for full circle locomotion.

I also use sunglasses/eyeglasses to protect my eyes from wind and bugs. When a bug gets in your eye at any speed you're in critical danger. I highly recommend eyewear.

Helmets have changed so much since I began riding. At first they were very heavy and poorly ventilated. I didn't use a helmet for my first 20 years of riding. After I started wearing a helmet I had a few wrecks where I was very glad to have the skid lid. I've seen folks with skater (non-vented) helmets riding bicycles. Altho they are adequate protection in my book, the lack of ventiliation is a huge problem.

I have been annoyed lately by my shorts riding to work. There is a little binding after the downstroke so that the pants (short) leg stresses against my leg. Am I getting picky in my old age? Bike specific shorts are stretchy and don't bind unless they are too small.