even at 56mm it still gives you a couple of Suzuki oversizes or even more overbore options if you use the 0.25mm increment CR/MT125 pistons, set the lower locating pin to match the RM pistons and it's all go
I'm in the process of seeing if I can go to 61mm safely as I have alternatives starting at this size which theoreticaly bumps capacity to around 163cc. May need some headwork tho.... both the bike and for me to even consider trying it
