Is there an easy way for a third party to confirm whether a used kayak is an RPM or the larger volume RPM Max? Other than the seller’s word, registration, decal, is there a code letter/number in the hull number, or a specific differentiating dimension between the two?
Length And Beam Difference
RPM 9’x 24.5"
RPM Max 9’2"x25.5"
sing
LOA?
Thanks. I’m assuming that those are length-overall measurements, not “around the bend.” Not a big difference, suspect there must be a little in the height as well, and the volume adds up.
Hmmmm
According to the Dagger website:
Max 9’2" by 25.75"
RPM 8’11" by 24"
But then there is a lot a variation between boats with the same official measurements.
I gather you have some reason to question the I.D. Can you sit in the boat? The difference is quite striking. If you are large you will not fit the RPM.
yep
I am 6 feet, but with 33 inch inseam–had to get the RPM Max as the RPM didn’t allow sufficient leg room. Needed a lot of padding out to handle wallowing around in the cockpit, but it rolls well. Still, it is easier to roll a Pintail or an OI. If I wanted a specialized rolling “cheater” boat, I’d buy or build a SOF before I’d rely on a whitewater boat.
Huh?
an RPM as a “cheater rolling boat?”
I guess it could be. Goes back to how one sees rolling. Is it “end” in and of itself, or just a “means” to something else?
RPM is a good starting river runner. Does some intro surfing as well (using shore side stern rudders). That’s what I would consider the RPM for as opposed to rolling. How easy/hard a boat roll is not part of my consideration as opposed to what the boat is designed to do in a specific venue. If rolling ease is the primary consideration, never sit on a HP waveski!
However, it goes to show, that this kayaking has so many facets and can be a bit of something for different folks. 
sing
I agree
I don’t find the RPM any easier to roll than my OI or Pintail, and no where as easy as a SOF cheater rolling boat. I bought it to use in winter pool sessions, but wouldn’t buy one just to learn to roll.
The RPM Max also has a flatter bottom
though the difference would be seen only to the practiced eye.
The BIG fact is that Dagger molded the identity of these boats into the plastic. If you buy a boat “said” to be an RPM Max, and it doesn’t say “Max” on the hull, then it is not an RPM Max, no matter what the seller claims. There are >absolutely no exceptions< to this, and anyone who says otherwise is a liar.