Like some of you I also had a problem with the mains not going up because rotation wasn't smooth. After partially disassembling them and rotating them by hand a while with little improvement, somewhere in the comments here on RCU somebody said to compress the struts... As soon as I tried that, the mechanism became silky smooth, very recommended!
The geometry on this landing gear is not the best and the last bit of movement has basically no stroke left from the piston to work with, so it needs to be as smooth as possible...
Just posting in the hope anybody else with the same problem can see this and spend less time than I did figuring it out!
Thanks to the RCU contributor who originally gave this advice, whoever you are~