Hello All,
There does not seem to be much info on the Primo Racer tires so I figured I would give a bit of a mini review.

The reason for me trying them is that one of my Right Runs suffered a case failure where I developed a pretty sizable bubble. I have always been a bit of a tire geek when it comes to my cars, bikes, RC cars, so I wanted to try something different than the Right Runs. Don't get me wrong, I liked the RR's a lot compared to the Marathons that came on my chair's stock wheels but figured I would change it up a bit.

I mounted these on Saturday and have put 4 days on them all of which were pretty active including 7+ miles of pushing on my walking/rolling route as well as going to a ball game and just being out and about.

-Weight- I did not have my scale when I changed out but holding them they feel very similar
-Quality- The Racers look and feel a bit nicer to me. The colored part of the tire is very uniform on the Racer whereas the RR was not terribly consistent. The Racers just look like they are better made.
-Mounting- Both the RR and Racer were pretty similar in mounting difficulty. Neither one of which is terribly difficult when compared to say the Marathons which are a bit of a bear.
-Rolling resistance- The Racers show a max PSI of 110psi, the RR's go to 145psi. I am running these tires on a set of Spinergy Carbon Blades which have a max PSI of 120PSI which is what I ran the RR's at. At 110PSI in the Racers I feel like they may be ever so slightly "slower" then the RR's. Keep in mind that this is totally subjective but what I feel but this may be that the Racers are running 10psi less. With that said I may try 120PSI in the racers and see how they feel.
-Grip- The Racers feel much more sticky then the RR's. This is true for both the traction they get with the rolling surface as well as on the sidewalls. The sidewall grip is interesting. I can get a better grip using either the hand rim (I use narrow spacing) or pushing on the tire. With that said I find that if I am pushing long distances I need to wear gloves as my hands get sore, right below my thumb from the rubbing on the sticky sidewall. This has only been an issue during my walk/roll with my wife which is about 2.5 miles long. I do wonder if the sidewalls will loose some of their grip with usage.
-Durability- I am not sure yet as they are so new. I have only been in the chair for 3 months but the RR's were already showing some pretty significant wear. To be honest I am not to concerned about tire wear as I am pretty handy and have no problem switching tires myself.
-Sizing- This is interesting, the RR are listed as a 23-559 and the Racers are listed as a 20-559 but in reality the Racers and slightly larger then the RR's. There was no need to adjust the brakes but they are most definitely a bit tighter.

All in all I like them, they are a much better looking tire then the RR's and seem to have a bit higher build quality.

Cheers,
Jim