When I moved up from a little TTR 125 to a full size 250, it was a shocker! My balance was bad and all I wanted to do was touch the ground. There are somethings a person can do to make it better but at my height 5’2, being able to touch flat footed on both sides is not going to happen. So, what do you do? ADAPT!
You can lower the bike. It is recommended to lower it through the suspension instead of other options. 1 inch seems to be the most common. My current race bike, 2018 Beta 250 Race Edition is lowered 1 inch and I am personally glad I did it. It does help me in technical areas where I absolutely need to dab a foot. That much lowered only allows me tippy toes. Another option that many riders do is buy a Seat Concepts low seat. It does make you feel lower to the ground.
BALANCE is key! The better your balance, the less you will have to rely on needing to touch the ground. I recommend doing balance drills on and off the bike often. It makes the difference.
Pay attention! Don’t just stop and put your foot down. That will bite you more times than not, I know from experience. Plus, when riding with a group and you randomly fall over from not being able to touch is embarrassing. Try to spot places that are more even ground when you want to stop.
Another thing that used to bite me often, not keeping my feet on the pegs when in motion! It was always in my head; I need to touch the ground for more balance but that is wrong. It led to many unnecessary wrecks. It took many times of being told, “Keep your feet on the pegs, your short little legs will not be able to touch anyway.”
Being short, a big bike might be intimating and seem heavy to balance. Use your legs! Ryan Hughes posted a great video the other day and explained this well! “The weight of the bike is low centered not up by the handlebars so that means your control of the bike should also be low, your legs.” There is a lot more strength in your legs than your upper body, use it as much as you can.
Lastly, be confident. Know you have the ability to ride a full-size bike. If you believe it, you can do it!