Installing new grips
Don't think grips are important? Try experiencing one coming loose when you're flying off a jump at a motocross track. Or try having a grip start to rotate as you hunch down behind skimpy fairing in the pouring rain. Those two pieces of rubbery stuff are every bit as essential in controlling your bike as your brakes and tires. Lose a grip (literally) or have one start twisting on its own, and you've lost your best link to steering the bike.
Installing different grips is also a way to customize your bike to fit you and make it more comfortable. Have small hands? Thinner grips will give you a reassuring handle on the bike. Vibrations giving you numb fingers? Mount either a pair of air-cell foam grips or ones with gel inserts to help tame the vibe monsters. Ride in the mud? Then get grips with ribs and ridges. Got big mitts? Grips run from 4-1/4" to over 5-1/2" long, so look for these XXL versions.
When you buy grips, grab some grip glue that's compatible. If you're a dirt biker, snag a roll of stainless steel safety wire. In addition, dirt bikers should think about purchasing a pair of grip end protectors (hard plastic inserts that minimize grip damage from falls). If your street bike has separate metal bar ends, remember they are there for a reason-anti-vibration. You can replace them with something more decorative, just be sure you find the right type. Some are intended for threaded fittings, while others have an expanding rubber anchor.
Grips are available in many different styles and colors. Foam and gel insert grips absorb vibration. For riding/racing in muddy conditions, install grips with lots of ridges. If you have small hands, there are slim grips available so you won't feel like you're wearing mittens. Finally, some grips are all about making a fashion statement. Whichever grips you buy, here's how to install them.
Step 1: Remove the old grips. It's usually not worth the hassle to try and save them, so just cut them away with a razor knife.
Step 2: Clean off any adhesive residue with mineral spirits and a clean rag. Make sure your throttle is working properly, and if you notice any binding or grinding, remove it and clean the throttle assembly and handlebar. Note that some brands of dirt bikes have a throttle tube with large ribs that will prevent you from adding new grips. You can shave the ribs with a razor knife, or replace the throttle tube with a smooth plastic or machined tube, which has the added advantage of being more crash resistant.
Step 3: Check the grip and its packaging for marks indicating whether it's meant to be installed in a certain direction, as some are.
Step 4: Install the clutch (left) side first. Dribble beads of grip glue on the bar, then a bit more inside the grip. Immediately slide and rotate the grip onto the bar, aligning any directional marks as per Step 3. Use a paper towel to wipe any glue away that oozes out. (By the way, some street bike grip instructions talk about using soapy water to install them. Me, I sometimes ride in the rain and don't consider soap an adhesive. If it's raining and I'm on a bike, I figure I have enough things to worry about without wondering whether or not the grips are going to come loose.
Step 5: The biggest headache when installing the throttle side comes from excess grip glue getting into the housing and gumming things up. Prevent this problem by sealing the hole (if there is one) at the end of the throttle tube with a piece of duct tape. Then apply grip glue as per Step 4 and install. If you can't get the grip on the last few inches because of built-up air pressure inside the bar, prick a small hole in the end of the grip with a needle to release the pressure.
Step 6: For dirt bikes, while the grip glue is still wet, cut four pieces of safety wire and wrap them around the grips in the shallow grooves that most dirt bike grips offer for exactly this purpose. Loop it twice around the grip, and then twist it tight with a pair of pliers at the bottom of the grip. You want the safety wire just slightly cutting into the grip.
Step 7: Cut off the excess and fold the sharp metal end over and into the grip, burying the wire's ends in the grip itself. Generally you use two pieces of safety wire per grip, but some grips have a third groove for a wire in the middle as well.
Step 8: Resist the temptation to immediately try out your new bike modification and let the grips dry overnight. The next day, before riding, check the throttle to be sure it is working properly and no grip adhesive has gotten inside. If it hangs up or seems even a little sticky, take the housing apart and clean any excess adhesive on the bar or inside the throttle tube.