Most tire manufacturers offer tubes for radial tires.... We used to use radial truck tubes in our drag slicks .... and we ran Z rated radial tires (with the tread "shaved") for 2 years on our Vega away back when... the owner of the local tire shop, who has helped me since forever it seems, gave me thw "low-down", if you will on the use of tubes.... the biggest concern is that, in usual street/road applications, tubes tend to be responsible for extra heat build up..... at Bonneville, though, with our air pressure in those radial tires being in the 65psi range, it was his opinion that the tire will not really be acting like a radial tire as the extra air pressure will tend to "stiffen" the tire and, since the tire is not being subjected to cornering, there is little, if any concern about the flexing usually associated with a radial tire and the resultant friction between the tire and tube actually causing any real amount of excess heat in a LSR application.