In a typical trail ride or enduro race there are several types of terrain: gravel roads, fire roads (two-track), and tight woods (single-track). Each are handled differently, so you're riding, and thus setup, has to be a compromise between them. For example, in single-track, you want low tire pressure for traction. But, if it's too low then you'll risk pinch-flats in the faster two-track or gravel roads. You need to consider the needs of all three when making setup decisions.
So, first things first:
- Get your suspension set up as best you can. Read here for more information on that while understanding that you want to keep things on the soft side for single-track. Stiff suspension may make it easier to take big hits in the fast stuff but it will kill traction when things get tight, when you really need it. You'll lose more time bouncing off a rock and into a tree on a single-track section than you will slowing down for some cross-ditch on a fast section of two-track.
- Adjust your fork hight in the triple-clamps. Some people like to raise the forks up an inch, or whatever they can get away with, in the triple-clamps. This means loosening off the triple-clamp bolts that grip the fork tubs and sliding the tubs up so they project above the top of the triple-clamps. Raising the forks this way will effectively lower the bike slightly, but it will also change the handling. Personally, I prefer to keep the forks flush with the triple-clamps, but then I'm tall and I like a light front-end. This really depends on the bike and rider; there's no right way for everyone.
- Adjust your handlebars. It amazes me how many people just ride their bikes with the handlebars set to where the dealer assembled them. Dealers just stick them on; they're not setup for you. So, put the bike on a crate, with the wheels about level, loosen the bars and sit on the bike. Adjust the bars so they're comfortable, then stand up on the pegs. Adjust the bars so they're comfortable. Now you know the range, low to high, where the bars should be. From there, it's just a matter of finding the best compromise between comfort sitting and comfort standing. If you do most of your riding on gravel roads, while just sitting like a lump on the seat, then adjust the bars towards the sitting-comfort zone, while making sure you can still stand up well enough to ride if you need to. If you're always standing up on the pegs while off single-tracking, then adjust the bars to the high side of things. So many people have told me they have trouble riding while up on the pegs when it's obvious that their bars are too low to ride that way. You can't ride properly if you're not comfortable. Don't forget to tighten the bar clamps when you're done.
- Adjust your hand levers. Loosen them off and adjust them so they are pointing a little bit downwards. The idea is that they should be neutral to your hand angle while you are in the "attack position." The attack position is when you are standing up on the pegs in a crouch with your head a little forward, somewhat over the bars. Your legs are bent, along with you're arms, so they can absorb any impacts that come along and your weight is balanced over the bike's centre of balance. This is the way you should ride when you're going fast on two-track. With single-track, try to stay in the attack position as much as possible, but reality might say otherwise. Usually, you're just trying to stay on the bike. Anyway, your levers, both hand and feet, should be the most comfortable in the attack position, so that you tend to stay there as much as possible. Now, tighten up you hand levers until you can just move them around by hand. That's right, don't torque them down so that they'll never move. When you fall over and your levers bite into mother-earth, something will have to give. It's much better for your levers to just move out of the way rather than bend out of the way. You can always move them back. Keep them a little loose and you'll save a lot of money on replacements.
- Adjust your rear brake lever. There should be a bolt the adjusts the high-point, where the lever normally sits waiting for you to use it. It should be accessible when you are in the attack position. Most people like it to be about level with the footpeg. Depending on your bike, you may have to re-adjust your rear brake after doing this.
- Adjust your shift lever. Sometimes, it's about right from stock just by adjusting it up or down on the shaft splines. Other times, you have to get more creative. This is where a shop with a welder gets handy. I've beat and bent my shifter all over the place to get it at the right hight for me, while still clearing everything on both up and down shifts. Some people lengthen their shift levers. I've used a torch to heat it up to make it more bendable (after removing the rubber tip), and I've welded up the cracks that inevitably appear. Don't start this unless you're prepared to deal with the consequences. However, getting the shift lever right can make a big difference while riding. Oh, and don't hammer or torque your lever when it's mounted on the bike; you really don't want to bend the shaft that goes into your transmission. Take the lever off, make your adjustment, and then fit it back on the bike for testing. When you're done, make sure you tighten up the mounting bolt as a loose shifter is hard on the splines.
- Adjust your tire pressure. Now, this one really depends on a lot of factors: how fast you ride, how heavy is the bike with you on it, what terrain you ride on, do you have wheel locks, what kind of tires... Lots of variability here. On my old XR250 dirtbike, with wheel locks, I used to run 12-15 psi in the rear and about 16-18 psi in the front. On my KLR650, I usually run about 18 psi in the rear and 19 psi in the front, unless I'm doing a highway run; these kinds of pressures will tear off knobbies with too much road riding. I'll also bump up the pressure significantly if I'm riding two-up. Also, these pressures are what I run with MT-21s, I ran higher with the Kendas. More on that here. Anyway, pressure is a very personal thing; everyone will give you a different answer. Basically, unless you run wheel locks, don't go below about 16 psi unless you have a really solid bead or you might spin the wheel in the tire. That will tear off the tire stem and give you an instant irreparable flat. Other than that, the lower the pressure, the better your single-track traction will be. The lower the pressure, the more likely you'll get a pinch-flat at higher speeds. And, the lower the pressure, the more likely things will get squirrelly at high speeds on pavement. So, like most things, it's a compromise.