1oz in the front, 2 oz in the rear. I have tubes in my tires. Yes the applicator works with tubes or tubeless. I use the valve cores that came with the tubes, no problems. In my van the plain cores didn't work as well. Needed the filtered cores.
If you look on the site Click tire charts on the left, then motorcycles. This leads you to a chart that tells the amount you need for the size tire. Front 80-120 mm use 1 oz, bigger gets 2. Rear 130-240 is 2 oz. They don't list rears smaller than 130 but I think that the 1 oz should be fine if you use smaller tires. Like most of the 18 inch.
If you click Products and prices scroll down to Motorcycles and scooters, Item DBS-BP2 is the ones I ordered. If I had the 18 inch rear tire I would use DBS-BP1.
The only thing is the hose they send works to install the beads but a longer hose works better. I went to the hardware store and bought two feet of some cheap clear hose the same size. As you pour them in, if you go two fast they plug up where they go into the valve stem. Then you have to rotate the wheel so they run back into the bottle, then rotate back so they pour in. With the short hose this is hard to do. With the lonmger hose you can see better and control the speed better so you get less clogging, and rotoating is back and forth is easier.
The price is good compared to regular balancing and they can't fall off and mess things up. When you replace the tire you can take them out of the old and put in the new. So you never need to pay for balancing again.
Leo