A few words before we get started on installing the new rubber.
Your primary task in installing a new tire is protecting the tube from damage. You want to make sure the tube is lying straight throughout the tire, so that it won't chafe on itself and cause a flat. You want to make sure not to damage the tube with the end of your tire iron. You want to make sure that the valve stem is nicely aligned with the hole in the rim, so that it doesn't rip the stem from the tube upon shifting.
New KTM's often locate the valve stem hole relatively close to the rim lock hole, which is very convenient for tire changes as we are about to see, although it does not help the balance any. However, many other makes will have the valve stem and rim lock opposite- I'll cover that eventuality in a moment.
Some dual-sporters like to run 2 rim-locks, to improve tire balance. I've done this, and it does help with balance, but it's a bitch to install, and no way around it. We'll save that for the advanced class. Personally, I never bother anymore. I really can't feel the difference when push comes to shove.
As above, if doing the rear wheel, it is nice to work on the side opposite the sprocket. Plan accordingly.
I do not use any soap or water- I prefer the tire to be a little sticky, so that it holds position as I work on it. Others disagree with me. Experiment and make up your own mind.
Step 1: install the valve stem and add some air to the tube. The goal is to give the tube enough body to roll itself out of the way of the tire iron or etc, without making it hard to get the bead into the dish of the rim. Another important function of adding air before you start is that it will ensure the tube lies flat, with no twists or kinks, inside the tire.
You will be hard pressed to flat the tube with your tire iron if you have added some air first.
Step 2: Install the tube in the tire (I cheated here and put the tube in the tire before adding air).
Step 3: Align tire/tube combo with rim/rimlock combo, so that valve stem is ready to pass through the hole.
Step 4: If the valve stem and rimlock are in the same quadrant of the wheel, you've got it easy, because you can pass the valvestem through the hole in the rim, and align the rimlock all at the same time.
If they are opposite, just worry about aligning the rimlock for now. I'll show pics of how to deal with the valvestem in a moment.
Aligning the rimlock- you want to push the rimlock down, so that it is between both beads of the tire and when the time comes, can suck the beads up and into the rim as it is designed to do. Trust me- if the rimlock is not inside the beads, you will not pass go, and you will not collect $200 no matter how hard you try.
Here the valve stem has passed through;
And here the rimlock has been pushed between the beads and the tire is ready to be pulled on.
Step 5: Pull the first side of the tire down onto the rim, taking care as always to keep the bead in the dish of the rim.
If you could not slide the valve stem in at the outset, here's where you do so:
Note that the valve stem is aligned with the hole it will pass through.
This picture sucks, but all I'm doing is shoving the valvestem inside the tire.
And this picture sucks too, but I'm lifting up the tire from the opposite side (the one that is already on) so that I can move the valve stem into the hole.
So, now we've got one side of the tire on, the valve stem and rim lock positioned correctly, and the second side completely off. We're in the home stretch.
Step 6: The second side of the tire. You want to start with the portion of the tire immediately adjacent to the valve stem, so that the bead of the tire won't trap the tube adjacent to the valve stem.
From there, you want to work the shortest route toward the rimlock. If the rimlock and valve stem are exactly opposite each other, whichever direction will be fine.
And finally, you want to finish the tire off 90 degrees from the valvestem and rimlock, so that they are not in the way of getting the bead into the dish of the rim. As always, take care that the opposite bead is down in the dishâ€¦
Step 7: Air the tire up. Always fill tubes slowly- not from a 120 psi compressor that's all charged up. Filling the tube too quickly can result in a twist that does not resolve itself. Bicycle floor pumps are best, but if you must use a compressor (I do), just switch it off once it hits 40 psi or so.
Step 8: tighten the rimlock- this should always be done after adding air to the tire, so that the tube has no chance of being caught between the rimlock and the tire bead, AND so that the tire has the best chance to seat evenly.
Mmmm... Fresh Meat...