Bike Condition:
Tuned/jetted for altitude – There isn’t much air up here in Colorado, so jet accordingly. All bikes are different and each will need a little fine tuning in this regard. Most of our rides are in the 8,000 to 9,500 feet range, but some rides, like Taylor Park are up around 10,000 – 11,500 feet. There is a long stretch of the Gunnison spur trail that runs right along the 11,500 foot contour line.
Chain and Sprockets - Your chain and sprockets should be in good condition. If the teeth on the sprockets start to get a little hook in them, it’s time to change them. Change the chain with the sprockets as a set. If you don’t have an “O” or “X” ring chain, then get one. These type of chains only need enough lubrication, such as chain wax, to keep superficial rust off of them. The internals are lubed with grease that is sealed in by the “O” or “X” rings. So don’t waste your time and money on those really nasty gooey chain lubes. Check the chain slack before each ride for the correct amount (your owner’s manual will tell you how to do this). From time to time, go through each link and work them back and forth through their range of movement and look for any binding or unusual stiffness.
Air Filter – Keep in clean. It’s that simple. Some people clean theirs after every ride. Personally, I look at mine and if it looks brown, I clean it. It depends upon how dusty the riding conditions are and how close you follow the guy in front of you and how many miles you ride. I recommend cleaning after every third ride or so, ranging from 1 to 5. One neat trick I have adopted is to use filter skins. They come in packets of 3. Clean them with a non-flammable solvent and treat them with filter oil along with your filter. You put these over your filter. When the skin gets dirty, replace it with a clean one. When the third one is dirty, remove it and run with just your filter (no filter skin) and when the filter gets dirty, then clean and treat the filter and all 3 skins and start over. I go about every 1-2 rides between skins.
Coolant – All you air cooled engine guys go take a break right now. However, most dirtbikes now-a-days are water cooled. Use a mixture of 50 % coolant-antifreeze and 50% clean water. Your coolant should be compatible with aluminium for sure. I use regular Prestone antifreeze and distilled water and change it every year.
Engine/transmission oil – Change it frequently. Check your owners manual for type of oil and change frequency. I personally change my 2-stroke oil after every 3rd ride. I change more frequently if I have gone through a lot of deep water crossings or have been riding in really dusty conditions. The older 4-strokes that hold a lot oil (XRs) can go longer between changes, but the newer 4-strokes hold smaller quantities and need more frequent changes similar to a 2-stroke.
Bearings – Check these frequently. Every time you change a tire, check your wheel bearings by holding the wheel with just your fingers in the bearings and spin the wheel while listening and feeling for any catches or grinding. The wheel should spin smoothly and freely. When your rear wheel is off, also check the swingarm bearing by moving the swingarm up and down and again listening and feeling for any catching or grinding. While your bike is on a stand and the front wheel in the air, move the front wheel back and forth through its entire movement. It should be smooth and easy.
Washed – Say what? When you wash your bike, you will notice if any damage has occurred and it’s much easier to see problems on a clean bike than a dirty one. Do not use power washers, unless of course, you don’t mind replacing lots of bearings! Use a gentle spray from your garden hose and never focus a strong jet of water towards the wheel bearings.
Shock and fork – Make sure your fork seals are not leaking. Set the rear shock sag for your riding weight. This is the amount the bike sags down in its suspension with you on it. Check it with all the gear on that you normally ride with.
Spark plug – Check this frequently and replace if it is looking grungy.
Your dirtbike should be wearing the following:
Spark arrestor and quiet muffler – A spark arrester prevents sparks from coming out of your engine and starting a fire along the trail and is required by law on public lands. The muffler keeps your bike from unduly annoying your fellow riders and other trail users. Colorado state law requires 99 decibels or less. If you come to one of our sound test sessions you will note that bikes under 94-97 are not too objectionable and the ones in the eighties or low 90’s are down right quiet. 100 and above are really obnoxious. If you have a high performance muffler, you are probably in the 100’s and not suitable for trail riding.
Brush guards (aluminum re-enforced type) – Protects your hands from brush and trees while riding and keeps your brake and clutch lever from breaking off when (not if, but when) you drop your bike.
Skid plate – protects your engine and frame when the bottom of your bike hits a rock. Bottoming out on a rock doesn’t happen very often; maybe once a year if that. However, if you do this without a skidplate, you can, and likely will, flatten the frame member at the point of impact, thereby drastically weakening the frame.
Heavy duty tubes. No, make that “Ultra” heavy duty tubes as the MSR variety that I like are referred to. Also, run adequate air pressure so you don’t get a flat from the rim pinching the tube when you hit a rock or log really hard. A good rule of thumb is to run between 12 and 14 lbs. I personally run 14 pounds both in front and rear. This really depends upon your riding style and how much you and your bike weigh. The more aggressive your style and/or the heavier you and your bike are, the more pressure you need.
Gas tank for carrying enough fuel to ride a minimum of 60-80 miles . Generally, this means a 3 + gallon tank. Lots of enduro style bikes have 3.2 gallon tanks (as opposed to motocross bikes that only have 2-2.5 gallons.
There are lots of other things good for trail riding that don’t come stock on dirt bikes as well, but the items above are bare minimums. Check out your fellow rider’s bikes for more ideas.