Hi. I have recently just built up a MetaAM29 and have a set of 27+ wheels to go on it. The chainstay on the AM29 is quite generous and wide at exactly the right point for 27+, however the seat-stays are a little narrower. Ive not ridden it with them yet but ive tried a few of the available options in the back to see how much room there is.
On a 45mm WTB Scraper a 3″ nobby nic has barely a few mm each side, too tight. A 3″ WTB bridger is equally close. A 2.8″ trailblazer has plenty of room.
On a 35mm Velocity rim a 3″ nobby nic has a little more room, but still looks likely to rub. A 2.8″ trailblazer has plenty of room.
I will hopefully receive a set of 2.8″ Nobby nic tomorrow I plan to try for fit at the weekend so will post back how that goes.
Having just built the bike up with 29er wheels Im still setting it up but found the back really plush even with a lot of air in, to the point I was getting pedal strike a bit. Maybe I need more air but im still playing with it so fitted 3 red bands to my monarch shock which seems to give it some good progression. Im not going to ride the 27+ till ive got this sorted (as id be selling them if they will lead to pedal strike, and ill get more ££ if they are unused :0) ) but will give feedback if I do, seems like shock tuning will work out so hopefully soon.
Here is mine with its 29er boots
[url=https://flic.kr/p/E2E4dh]Untitled[/url]