No. The Rebel speedometer is notoriously overly optimistic about speed. When it indicates say 65 mph, actual speed is several mph slower. Had a 2004 Tundra with oversize tires and it was spot on at 70 mph as verified by several roadside radar displays. Current 2006 Tundra, with standard size tires, is about two-three mph slower at the same indicated speed.
That’s what I figured you were trying to say. But what you wrote seemed to say the opposite, i.e. your indicated speed (on the speedometer) was less than actual. (Although with the double negative in the bolded statement below it’s a little unclear to me.)
We have many permanent radar speed monitors in our community, which display vehicle speed as you pass. So far on my bike at speeds up to about 40 mph the Rebel speedo and the radar are in exact agreement.
I don't have a bike that indicated speed isn't lower than actual speed when fitted with the recommended size tires. Pretty much the same for every cage I've had...