The larger tires of the RR and RW remind me of the high school experiment of how a gyroscope works when you spin a bike wheel in a swivel chair and tilt it left or right to go in a circle. I'm thinking the same thing is happening a little bit with our ebikes with plus and fat tires.
You could try the process of elimination like:
- Spokes: a few of my spokes were loose out the box and I re-tighten them after I ordered a spoke tool from Amazon.
- PSI: my old Kenda felt consistent from 12-22 PSI. Switch to Vee8 a few months ago and experimented with PSI from the 15 to 25 range. The Vee8 pull harder to the right the lower the PSI. I have to keep the PSI above 20 to lessen/eliminate the feeling. I would play with the PSI in the upper range to see if that helps.
- Fork damage: my disk brakes were out of true from shipping damage and other Rad Power Bike owners had bent forks on their Radwagons replaced under warranty. Hard to figure this one out unless you take to a shop or have another Radrover to compare. I was lucky to have my wife's RR as a reference. I wasn't able to bend the brake disk back 100% true; but, zero rubbing after I switched front tires between the two RR.
- Tires: maybe the tires are mounted backwards or an issue with the tires itself? I would try and switch the front and rear tires to see if that makes a difference. Might have to upgrade your tires to Hookworms or Vee8?
- Too light on front end?: The Radrover is already tail heavy and a very upright riding position. My wife commented on how the Radrover doesn't feel as stable at +22 mph when pedaling in top gear to her (4'11" 125lbs). I've gone as fast as 25 mph in top gear downhill and Radrover still feels good to me (6'3" 270lbs). It could be just the amount of weight on the front wheels making the RR feel more or less stable? I now add the extra gear in the rack bag on her bike when we are riding together (water, locks, spare battery, etc...).
- Balance out the bike: maybe having more weight up front (using both bottle cages for water/locks) or even on the left side might help (always filling the left pannier first with the heaviest stuff).