[Hanno Spoelstra]

As long as you make sure to fit 10.00-20 tyres, as a 10" x 20" tyre could be a different one altogether (look them up).

10.50-20 or 11.00-20 tyres were standard fitment for 20" wheels, so a 10.00-20 tyre will be a bit smaller than standard, so your road speed will decrease, pulling power will increase.