Hello There.
I am reviewing the specs for the new impacts and i found the twin bearing improvement, i just would like to understand what is the difference? is it smoother riding or has to do with something more technical…
thanks for the comments.
Thanks a lot, I fail to see that post from them.!
Thanks from here too 
32mm bearing review after 3 years:
Three years ago I built a 24" with an Impact Frame (discontinued, I think). The frame takes the 32mm double-wide bearings. The other day, some neighbors helped me put a second set of bearings on. The bearings had a shorter life than any other unicycle bearings I’ve used. But three years / lots of miles is not bad.
The old bearings were still technically working, but the wheel had a crunchy feel / sound while spinning it. And clunking sounds started to happen every few seconds while riding.
Turns out, one of the two bearings was in really bad shape, the other was okay. I am wondering if that uneven wear might have been caused by some uneven element in my riding.
We had to stack coins inside the crank puller to clear the distance the bearings needed to be pulled off the axle. My neighbors had a tool, a short metal tube with one rounded end. They used it, with a rubber mallet, to hammer on the new bearings.
I was pretty shocked by the difference in performance after installing the new bearings. The wheel turned really smoothly. I felt somewhat off-balance at the beginning of yesterday’s ride, due to, I think, the missing resistance of the wheel right at the weak part of the pedal stroke. The clunking sounds I mentioned above went away (with noises, it can be heard to tell where they’re coming from, but this confirmed that it was, in fact, the bearings).
Anyway, I am not disappointed in these bearings. Three years is pretty good for the weight savings I’ve gotten. I’m not sure the 32mm bearings would hold up well in conditions where more sudden or sideways force was placed on them, such as trials or street.
UDC, I think, ended their experiment building unicycles with these bearings. I had a bit of trouble finding them in stock. UDC was very helpful and found me a pair.
After the introduction of the 32 mm Twin Bearings, Impact offered a free replacement to 32 mm single bearings. I`m not sure but I think it was early in 2016. Now they offer their unicycles alternatively with 32 and 42 mm bearings, promoting the 32 mm bearings as pro version. This is what their webside says:
"– 32mm bearings are Impact’s performance bearing, providing a dramatic decrease in weight, as well as added stiffness. As a performance product, these bearings require maintenance and have a shorter life than 42mm bearings.
– 42mm bearings are used on almost all mid-professional tier unicycles. Although heavier than 32mm bearings, these bearings offer reliability and increased compatibility for other brand’s frames."
Thanks for finding that info. I am not sure what they mean by “require maintenance.” Does that mean they need replacing?
“require maintenance” is checking for damage and potentially replacing.