Bicycle Roller Trainer

You can also practice by placing them in a hallway. If you start to fall off, all you have to do is put either of your arms out and brace against the wall. Once you get it down you will be able to ride them comfortably anywhere... I'm not anywhere this comfortable yet! Haha

 

You did not watch the demo video. This set has built in resistance, slides fore and aft so you can stand on them without jumping off.
The kid in the video was doing amazing stuff trying to mess up but the rollers kept him on.
Pricey like I said but if I did not live here in SoCal and had to ride indoors for fitness then it's worth it to me. YMMV.

 

I watched the demo video, sorry, I guess I didn't get that out of it... Still don't think it's worth the money. I've never used rollers before in my life and am not a strong cyclist but I was able to get the hang of the set I bought after a few tries. $850 is ridiculous, if you want to stand up, jump around and do crazy stuff on a bike, go outdoors.

 

The site looks different than when I first book marked it and can't see the video I saw before. Not for you but there are plenty of people buying them.
Like I said I have plenty of time and great weather to ride outdoors but for some serious friends this is just what they want for an agressive workout with some safety features for when you mess up just alittle to keep you upright. When you spend $8000 for a bike what's another $800 anyways.