But a basic grasp of geometry is not what you're suggesting, you're suggesting highly specialist knowledge. My winter bike can easily fit 650b x 42 and has a standard road chainset so it's obviously possible.
Also stating the clearances a bike can take is not really dubious marketing, its a fundamental part of the bike specs. Something black and white that is or isn't true. If they'd have said 'the frame fits rad gravel tyres' but not specified the sizes and I'd not checked (4 times) then yeah maybe some blame would lie with me.
But a basic grasp of geometry is not what you're suggesting, you're suggesting highly specialist knowledge. My winter bike can easily fit 650b x 42 and has a standard road chainset so it's obviously possible.
Also stating the clearances a bike can take is not really dubious marketing, its a fundamental part of the bike specs. Something black and white that is or isn't true. If they'd have said 'the frame fits rad gravel tyres' but not specified the sizes and I'd not checked (4 times) then yeah maybe some blame would lie with me.