Just out of curiosity and while thinking about a good winter bike with decent tyre space:
does anyone have experiences with mixing wheel sizes (apart from 69ers)?

E.g.:
– Cotic Soul with 650B front wheel / 26 rear wheel
– Cotic Solaris with 29 front wheel / 650B rear wheel
– Cotic Solaris with 650B wheels on both ends

Here’s an example for the latter:
http://bikemarkt.mtb-news.de/article/274523-cotic-solaris-stahlrahmen-27-5-650b

The guy claims that he’s finally got decent tyre space, BB meant to be OK, steering still round despite longish fork.

Registering interest for curiosity reasons

Slightly OT but ….with a 2.25 Ardent in the back of my Solaris I never experienced clearance problems.

with a 2.25 Ardent in the back of my Solaris I never experienced clearance problems

Good for you! I’ve heard of people who like to ride 2.35 or even 2.4 tyres… 😯

Liteville are also big advocates of this:
http://www.bikerumor.com/2012/09/13/2013-liteville-mountain-bikes-updates-frames-w-scaled-sizing-mix-n-match-wheel-combos/

XL on order will come with a 26″ rear and 650B front.