Changing tires

[HamptonT]

I apologize for the rookie questions but I'm new at this. My 1980 ATC185 has Carlisle tires in the rear and the original ohtsu tire on the front. The front tire is worn. It still has some knobs but not much. It does not steer well in the snow or ice. I think it's partly because the tire is worn and partly because the original ohtsu is much larger than the carlisles. The size difference throws off the steering geometry and the center of gravity. I want to put a new tire on the front that is similar in size to the rears. Most likely just go with another Carlisle.
Is changing the front tire a do it yourself job or should I bring it to a shop? I believe the rims are split rims with a large o ring gasket.
Tubes or no tubes?
Thanks.

[RIDE-RED 250r]

Changing any tire can either be a do it yourself job or a shop job. Being an original tire that very possibly could have been mounted for 35 straight years at this point, I am going to say you might want to just take it to a shop. When they have been on a rim for so long the beads can be extremely stubborn to break unless you have a god bead breaker.

I would go tubeless if the split rim doesn't leak and allows you to.

[briano]

Here's how I do them when saving the tire is not important. Remove tire and wheel from the machine. Get a good sharp utility knife and cut the tire cross ways from rim edge to rim edge, cut out a section a couple inches wide, a bit of soapy water helps the knife glide across the tire. Take a cutoff wheel or dremel tool and cut down through the steel cords in the bead, don't cut all the way to the rim. Take a chisel or old flat blade screwdriver and whack the rest of the way through the last bit of rubber, now you can just pull the tire off the rim.

For the split rims, I take them apart and clean up the bead area and the o-ring surface with a wire wheel, make sure to get the o-ring groove nice and clean. Put one half of the rim down on a workbench and place the new tire over it. I use a little bit of black rtv in the o-ring grooves, now put the other half of the wheel in place. You should be able to reach through the center hole of the wheel to put the bolts back in from the bottom side so you can start the nuts From the top. Tighten the nuts evenly, air your tire up, and put it back on, go ride.