Originally Posted by
sweetspot
I think that the very interesting case is with new giant revolt 2019. It can take 45 mm 700c tire but only 47mm 650b according to what Giant has told me on their FB profile. It is a proof that not necessary all of 40c bikes can acommodate 47mm with smaller wheels.
Because in keeping a shorter chainstay, Giant (2019 Revolt) unlike........... Open cycle , Norco with the Search XR, 3T exploro, Salsa Warbird V4 (maybe more, brain isn't awake yet) Ibis Hakka MX, have all dropped the drive side chain stay to allow for the 650x2.1 (wider) tire size.
on the Flip side...... there are a large number of bikes that can take a 40c and also fit the 650x47..... but the 650 isn't by design. So take a bike with a lower BB drop for the 40c tire, and then by running a 650x47 the BB is another 12-13 mm lower to the ground. If my checkbook was larger, I'd try some of them bikes that have a lower BB with 160 crank arms and a 650x47 swap. yet a 650x47 on a longer chainstay, higher trail, Lower BB... doesn't seem like a very good combination for my spirited style of riding. Especially when it comes to riding the fatter tires Moto style and getting everything out of them they have to offer.
The the bike that was 'Designed' around 650x47 has a 65mm BB drop and shorter chain stay 425. The Midnight Special.
none the less, if WTB doesn't have your 700x40 Bike listed as fitting their 650x47 tire, a Longer chainstay might be a clue as to if it will fit or not.