If you have spoke wheels the tires have tubes.Does a inner tube change the speed rating,as in lower?
No, and tubeless can run with tubes. However there is a requirement if they are rubber stemed
Copied from the rule book:
7.B.8 Valve Stems and Caps:
All tire valve stems must be fitted with metal valve caps. Over 175 MPH, tubeless tires must use metal valve stems. Tube type tires with rubber valve stems that are angled relative to the rotational plane of the wheel must have those valve stems secured to resist centrifugal force deflection. Safety wire or other approved restraining device is required.
A: All motorcycle entries, must use tires with an appropriate speed rating.
B: The required speed rating is governed by the record speed in the class.
C: All competitors going over 187 MPH must sign the tire waiver form.
D: IT IS THE RESPONSIBILITY OF THE ENTRANT TO CHECK INFLATION PRESSURES AND TIRE AND WHEEL FOR DETERIORATION OR DAMAGE IMMEDIATELY BEFORE AND AFTER EVERY RUN.
E: Tires rated H CANNOT be used beyond the speed rating.
F: All production tires rated H, V, Z or ZR must have been produced within the last ten years as of the date of the current event.
G: Sidewall date coding will be checked.
H: Tubeless, bias ply type tires may be run with tubes.
I: Tires designed for use on the drive wheel in drag bikes are not be allowed.