what am I doing wrong?
 

I have a giant MTB and for the first time Replacing the tires but I cant get the tire to bead right on the wheel. I rode to work and found out a whoop whoop any ways I came home a and see the tire is not on the wheel straight. I let out air a rolled the tire but it wont sit right. Help please

The most common newbie mistake is trapping some tube under the bead.

Start by using the reference line molded into the tire along the rim line, to see where the tire is high or low in the rim.

High spots are almost always trapped tube. You can usually see it if you push he tire away from the rim and look in. The easiest place to free trapped tube is at the valve because you can push the valve in pulling any trapped tube out from under the bead. This is one reason I finish mounts at the valve. Elsewhere freeing trapped tube is harder. You can try dropping the pressure until the tire is limp, then bringing it up slowly to about 5psi and seeing if it pops free when you massage the tire.

Otherwise unmount and remount the tire, ending at the valve, keeping just enough air in the tube to keep it round (bleeding out the air out as you finish makes it easier).

If your tire is low in the rim in some places, which often happens on rims with inside shoulders requires lowering pressure to minimum to keep shape, and massaging the tire toward the low spot and pulling it up by rolling the tire away from the rim at the spot. Sometimes if you get it close, it pops up on it's own as you inflate.

BTW- before mounting, check the tire for any bent bead wire. Straighten it as best you can before mounting.

If your tire is low in the rim in some places, which often happens on rims with inside shoulders requires lowering pressure to minimum to keep shape, and massaging the tire toward the low spot and pulling it up by rolling the tire away from the rim at the spot. Sometimes if you get it close, it pops up on it's own as you inflate.

Tried this I can't get it rool up on the lip

This used to be a common problem, and we hear less of it these days because most modern rims are hook edge, not "Endrich" pattern with shoulders. Many years ago both Park, and Bicycle research made tools which were essentially big dull pliers for grabbing low spots and pulling them up. I don't know if the tools are still made, but you can DIY your own with something to protect the tire, such as thin blocks of wood, or flat metal, section of old leather belt, or maybe even popcycle sticks. Use a pair of Channellocks, to grab the tire through the protection and roll it up and out.

BTW- some modern tires are made for hook edge rims and less attention is paid to the ID at the bead. These can be a bit undersized and may never seat properly by the shoulders.

What usually works for me is to check what the max pressure is on the tire and inflate slowly until that level is reached(if it doesn't pop up before) and wait until it sets with a definite "ping" sound. Sometimes it can take a few moments for it to happen, so bounce it a couple times and let it set until it does. When it has settled, reduce pressure to operating settings.

Some rims have fairly shallow channels which makes mounting a tire a challenge when the bead fits deep in the channel. The best fix for this I have found is to replace the rim tape with a high quality plastic HP rim tape, ie Velox, Vittoria or Continental. The plastic rim tape allows the bead to slide easier to the inside of the side wall. When I ran into your problem I tried everything like you; it was only when I replaced the Velox cloth rim tape I had used with some Velox plastic tape that the the tires finally seated correctly. I changed the rim tape and the tires centered themselves and popped into place when I inflated them.

If somebody hasn't mentioned it already, you can try lubing the tire beads with soapy water or talc. I use the latter.

I got er fixed a little soap and water and about 80 psi and the both beaded right. Thanks for all the help.

Also check that you are not pulling the valve stem to tight into the rim hole. This will cause the tube to not seat into the tire once inflated.