I think on a 29er rim its about a 2.25. Someone said they tried a 2.35 WTB Vigilante and it rubbed when cornerning...Basically that sounds like the same issue I have with my 650B Switchback frame. I can't run a Schwalbe 2.35 as it rubs when standing up and peddling, so I had to use a 2.25.

 There is no 2.35 Vigilante

 Ok it was a 2.35 WTB something..let me see if I can find the post..

 Oh yes my mistake..it doesn't say what model it was on the rear, just a 2.35 WTB of some sort:

singletrackworld.com/forum/topic/stanton-sherpa-riders-your-choice-of-rear-tyre-please

 Yeah I realised after posting it that it was also posted in the sexiest hardtail thread a few days ago but it didn't mention about the tyres.

 Looks at this picture like five times since you posted it there and only just realised today that it isn't a Switchback!

 Yeah lol those tyres wouldn't fit a Switchback..It does look similar though..

 Stanton Bikes are offering the Sherpa frame with 2 wheel build options now. Regular 29er and 650B+.

 Although that bike in the pic is using a standard Hope 29er rim...not a fancy rim designed for plus sized 650B tyres...so make of that what you like.

 Had look further into this and I think not. It does say something about a Rocket Ron or a Trailblazer though.

2'.8" Nobby Nic on WTB i45 will fit and spin in a Stanton Sherpa but mud or out of true rims are definitely going to cause rub on the stays, not recommended.'

singletrackworld.com/forum/topic/650b-and-other-plus-sizes-if-you-like-rim-tyre-frame-fork-combinations/page/17

 @silverfish1974: i was looking on that forum aswell, thanks for the answer though!
Beautiful bike nonetheless