I've been using HED Jet 6+ with GP4000SII 25mm tires and have had zero issues with mounting them or getting flats. Coming from a FLO 90/Disc setup, I found mounting tires on the HED wheels to be stupid easy. I absolutely LOVE these wheels and tires!

What PSI are you inflating to?

I agree with the others regarding the videos to mount the tire. The flats could be either your tire pressure and/or road conditions.

If you're going to do this, I would recommend using a spare rim that is easier to mount the tire, and using a tube to inflate the tire to full shape. That will give you better stretch in the tire than if you put a the same tire on a hard to mount rim with no tube.

After the tip to make sure both beads are moved to the center of the rim before trying to get the tube out, I'm able to get the tube out with one lever and then change it and get the tire back over the rim. Thanks everyone who chimed in.

The second trick is that if you're still having a hard time getting the last section over the rim (when installing the tire/tube), instead of using a lever, put the opposite side of the wheel/tire against your waist and pull it into your waist. Effectively what you're doing is pushing the opposite side of the tire closer to the rim, which then should give you slightly more slack on the side you're trying to finish up. After you start pushing the wheel/tire to your waist, you may have to use one hand to keep applying the pressure and the other hand to slowly pull the the slack you just created from your waist area and work it up to the last section you're trying to finish. All you're really looking for is just 1-2 mm more slack so it makes sense to pay attention to the details.