That's good to know. What size tyres? I definitely had rub issues with 60mm GBs on my Kuwahara, but that was with a reasonable amount of clearance over 2 1/8" semi slick tyres. Could go closer on this.
Tires are 26x2.15 Schwalbe Big Bens.
I use a problem solvers adaptor for the front mudguard, but the rear is just fine.
It's on a late 90's Kona Lava Dome.
FYI, I run regular deore V's with 65mm bluemels mudguards and it is just fine.