Hang the wheel up, so there is nothing pushing on the tire. We hang it from an old handlebar we put in a vise, but you could hang it from a hook, or a bike stand. Position it so the valve stem is at roughly 12 o’clock. Main thing here is: the tire should not be touching anything like the ground, that would deform the tire.
Seat the tire. Lightly massage (push down on) the tire so that the bead is sorta near the hook of the rim. If the bead is say, letting the back of the valve stem be exposed, you will just blast air into the room, not into the tire. Hide that valve stem inside the tire. For fat bike tires, this is critical, you can run a tire lever along either tire bead to pull it closer to the rim.
Blast air into the tire.
Things get weird here.
- The tire could quickly seat. That’s ideal. When it does, the tire will sort of snap into place with a series of loud and startling bangs. The noise sounds like your tire is exploding. Fun! Clean out your pants, and carry on. Inflate it till it’s barely firm. That’s good enough for this first seating.
The tire is almost seating, but not quite. It’s getting some shape, but it keeps spitting soap around the room. You can sense you are close, but the tire is mocking you like that kid in gym class used to. Damn him. If this happens, you have to stop, take the tire off, take the valve stem out, and clean the tape. We use degreaser like simple green, then some denatured alcohol to get it really clean. Wrap another layer of tape over your existing tape. Poke another hole in it and try again. The almost, but not quite, seating tire situation is almost always caused by needing another layer of tape to tighten up the interface between the tire and rim. Easily solved, even if it’s a pain in the tookus. Assuming that’s how you spell tookus. You don’t want to add too much tape right off the bat. The bead seat tolerance on contemporary rims is pretty tight, and over-doing the tape can make mounting difficult.
The tire isn’t even close to seating, it’s just a floppy bag on the rim, and it’s very existence is chaffing your soul. Schwalbe ‘tubeless easy’ tires tend to have this issue, ironically. If you are using a Schwalbe, do this next step before you try to add any air at all. Big, really light, fat-bike tires need this step, as well. Take one side of the tire off. Pull out the valve stem. Stick a tube in there, reset the tire and inflate it. Get the tire fully seated, just like ya done did when you had tubes back in the dark ages. Put at least 30 psi in there on a mountain bike tube, 20 for a fat bike, and 60 for a narrower tire. Drain the air, and just open up ONE side of the tire, being careful not to muck up the seated bead on the other side. Pull out the tube, put the valve stem back in, remount the unseated side of the tire and try inflating again. If it’s still recalcitrant, massage the tire where ever you feel air blowing out while you are inflating it. This is easier with a air compressor and a friend. Cats don’t count. The tire should seat. If it doesn’t, add another layer of tape. If that doesn’t work, try adding one more layer of tape. If that doesn’t work, something is seriously wrong, and you should take up speed walking. Really, the rim might be damaged, or your tape job was terrible, or the tire has a massive hole in it
Take the air compressor hose off the valve, and let all the air drain out. Because the wheel is hanging in the air, and the tire isn’t touching anything that will cause it to deform, but it should hold all or most of its seal.
Shake your sealant like you are demonstrating a shake weight. Take your Orange Seal sealant and use the applicator hose to shoot 2-4 ounces of sealant into the tire. 2 oz for tires up to 35mm. 4 for bigger stuff. It’s light, and more isn’t bad. Eyeball this. Don’t get out the graduated cylinder.