Bike Adjustments
bar ends
brake lever
seat adjustment
tire pressure
I have noticed many beginner and novice riders have their bar ends pointing nearly straight up. This is interesting to see, as it isn't overly helpful on the road or trail. Usually you -- depending upon preference of course -- want your bar ends to be a less than 45 degrees from parell to the ground. This is for two reasons:
1) when your seat is adjusted properly (see below) it usually gives you a natural wrist placement
2) it gives you a comfortable postion to climb with
Brake Lever
Generally you want your brake levers to fall naturally where your hands are (when your seat is adjusted). This usually ends up being between 30 and 40 degrees below parell (to the ground).
Seat Adjustment
Having a properly adjusted bike is key to having an enjoyable experience. This is much like having a perfectly reliable vehicle, that is fast, good on gas, but does not idle well and dies at every readlight. The car is just fine, but driving to work quickely becomes annoying. So too is an improperly adjusted bike integral to having an enjoyable time riding.
Seat Selection
Choose a seat that is right for your needs. Many beginners automatically go for the widest / softest seat avaiable. This isn't a bad idea if you only plan on riding short distances; however, as you ride more you will soon realize this seat isn't the best all around. Most expirenced rides opt for a narrow or medium width seat. Ths provides good stability with long ride comfort. I usually choose a somewhat firm seat that has decent flex (from the body of the seat). Test ride a few bikes at the bike shop to see which seat will be your best match.
note: you don't have to pay huge amounts either... watch the sales and pick one up for $10 - 15.
Seat height
The "ideal" seat height takes a little measuring and patience for a beginner. Here goes:
1) If you have your bike stationary with you sitting on it
2) Put one pedal as far down as it can go
3) your thigh and the bottom of your leg should create a 30 degree angle with each other.
(this can be measured with a plumbob or with a protractor and some creativivity -- I choose the latter).
Seat Angle
The seat angle should be slightly less than parell to flat ground. Don't put the front of the seat higher than the back... it will hurt.
For guys, put the front of the seat a little "more" lower to the ground.
Lastly, if you are going off road, you should generally be able to be close to touching your feet (on your tip toes) to the ground. I generally adjust my seat up or down depending on mood and how tough the trail is.
Tire pressure
Tire Pressure usually varies between 35 and 100 pounds of pressure (psi). For most trail riding 35 to 40 psi usually works pretty well. More pressure and you start to lose traction, less you start hitting your rim on jumps and are more prone to "snakebites" (where your rim pinches your tube).