I have a HUTCH frame that measures 18 3/4" from center head tube to center seatpost, and 20" from center headtube to center bottom bracket. Pro Racer is 19 1/4" and 20", and Expert Racer is 18 1/2" and 19". So is what I have a Pro Raider? I am pretty sure but can't find the measurements for a Pro Raider? Pat.

Is serial # under bottom bracket and start with M, that would be a raider

That is what I thought, but the SN was ground off. Thank you Vader!! Pat.

Can't you also tell by the way the brake bridge is stamped? I thought the Raiders had the HUtch letters touching.

A Pro Raider will have holes under the chainstay right behind the BB, and under the seatstay behind the seat tube. Also the vent holes in the loop will be punched, not drilled. And if you have the fork, the bottom caps will be spot welded, rather than welded all around.

i've seen (and had, BITD) original decal US Pro Racers that measured 18 3/4". don't know what the deals was - using up tubing? intentional change? F*up? - but they're around.

i actually have a later US Hutchins Pro in that size, right now

tubing diameter will determine a "racer" from a "raider":

Racer = 1" toptube, 1 3/8" downtube.

Raider = 1 1/8" TT, 1 1/4" DT.