This from the Stumpy's page on the Specialized website:
"Steps were also taken to make this bike easy to live with. Threaded bottom brackets make a triumphant return, and we made room for up to a 3.0" tire."
I have yet to see one running 3.0 tires, either live or in any pictures. The ones running the stock 2.6 tires don't look like they have a lot more clearance, but I can't imaging Spesh putting this in print if it didn't meet minimum clearances with the bigger tires on them.
Rode a Trek Full Stache with the Bontrager 29 x 3.0's and loved the ride, so am very interested in clearances for the Stumpy.
Agreed, the ride of a plus tire is awesome. So, that is where I'm trying to get to with this bike. 2019 SJ Expert 29er with the stock Roval carbon 30mm id wheels.
As many of the tire manufacturers cannot seem to make a tire to match the labeled dimensions, and specialized made a frame that has the same loosely base tire-size-compatibility claims, it becomes a real project to find a tire that gets close to making this a plus bike.
Their claim on the 29er Stumpy home page; "...and we made room for up to a 3.0" tire." IS FLAT OUT WRONG!
The OEM 2.6 Butcher and Purgatory"s that came on it measure very close to 2.35.
I just mounted, and will be settling on, a 29 x 2.8 Terrene Cake Eater. After some helpful feedback here, and in a couple other forums, I also spoke with Terrene about the fit, and they confirmed that it would, but it it might be tight of the recommended clearances. Their website seems to be pitching it as a winter tire, but the in-house team says it is designed as a year round all mountain tire that can be studded for winter use.
The Cake Eater has a nice a/m tread and is definitely the biggest tire that will fit the rear triangle. Inflated it measures just about 2.6". The clearance at the seatstay brace is just under 4mm. Industry standard minimum is 6mm, so you cannot go bigger than this tire. The McFly' is built on the same casing, and has a faster rolling tread design, with center knobs 1.5mm shorter, so that should clear the seatstay brace better, with roughly 5.5mm.
Now to find something to fit the fork. Is anyone running a 29x3.0 Bontrager ZR or SE4 on this bike?