I have decided that I will try 29+ in both ends and see how this feels. The main reason is that I have a 6-inch trail bike with 27,5 wheels and this will be replaced with a 29+ FS when I can find a bike I like (maybe next season). Then I will have only 29er wheels except for the rear wheel on this accutal bike... Right now I have too many wheel (26, 27,5, 29) and tires (city, commuting, winther, trail, downhill) in my garage and I will narrow it down to only 29er.

Regarding chainring: I think I will follow your advice with a 34t chainring. Start with a 11-42 cassette and if this is to heavy i will boost this to 50t.

I can't decide if I should go for Sram or shimano drivetrain... Pricewise shimano is much better and the possibility to boost the cassette to 50t is also a point. Sram eagle is way out of my budget... How is the performance with Sram GX?

Given the drive side high chain stay, I would think a 34T chain ring would fit easily.

Also with 50t cassette in combination? If I do boost the cassette I will need even bigger chainring...

One more thing:
Does anyone know how big chainring and cassette combo is possible before the chain hits the driveside CS? I would like to go e13 9-44 and maybe a 34 in the front...

Enter!

I´m wondering if I should buy this frame and use different wheelsizes front and rear (27.5+ rear and 29+ in rigid fork). What do you think?