The main purpose of handlebar tape is to provide an easily grippable surface and comfort for your hands. Bar tape is made from a variety of different materials ranging from thin to thick, firm to cushy, and smooth to tacky. Without bar tape, your hands would take a lot more punishment, and control over the bike would be sketchy at best.
Bar tape comes in many colors, so in addition to aiding control and comfort, new tape is an easy way to add some style to your bike. Be aware, white tape gets dirty easily. Luckily, Windex cleans it up nicely.
Cotton tape is very thin, light, and is only slightly better than a bare set of bars when it comes to comfort. Classically, the end of a cotton tape wrap is secured with twine and the tape covered with shellac. There are cyclists who still like cloth tape, but it’s mostly used on older bikes to keep a vintage look intact.
If you’re looking for a more practical retro tape option, you might want to go with leather. The most durable of all bar tapes, leather tape will last for years, though it offers very little in the way of padding.
Cork tape is cushy and dampens vibrations, but loses traction when wet. It absorbs sweat well but will get overwhelmed quickly in the rain. Not the most durable option, cork tape must be wrapped perfectly or it will tear. Cork was the original “high-tech” bar tape, replacing leather and thin cotton tape. Modern cork tape is actually a cork/foam blend. These days, cork is usually the most affordable option.
Foam, both EVA and silicone, is commonly used in place of cork for a little more longevity. Foam tapes can be topped with a cover layer, or textured for extra grip, or left with a “raw” surface. Raw and textured surface foam tape has a better grip than cork and is more durable. It also performs a little better when damp or wet, but not as well as foam tape with a microfiber cover.
Microfiber covered foam generally provides the best grip, with effectiveness varying between different types of microfiber. Some microfiber cover surfaces are very tacky, maintaining high grip even in wet weather or when riding without gloves. Suede-style microfiber surfaces are less grippy than the microfiber with a more rubbery appearance. Microfiber-covered foam tapes are also the most durable style of grip other than leather.
To increase vibration damping and provide some extra hand relief, gel inserts are a common addition to bar tape; Gel is either attached to the top or bottom of the foam, or sandwiched between layers. Separate gel pads are sometimes placed directly onto the handlebar before wrapping the bar with tape.
Double wrapping bars with two layers of tape is another way to get extra cushioning. Double-wrapped bars are also good for riders who want a larger grip, or have big hands.