A 34 front and 11 back on a 29 is the same as a 32 front and what virtual size cog on the rear of a 26?

this is quite helpful;

http://www.bikecalc.com/gear_inches

[edit] you’ll be looking at about a 5 tooth cog on the back with a 32 at the front.

34×11 on a 29er gives you 88.8″ depending on tyre size. The closest you get with a 26er using a 32 chainring is a 10t sprocket that gets you 86.3″.

It’s simple maths !

(26 x 32) / (29 x 34 / 11) = 9.3 teeth.

Now, that assumes your 26″ wheel really is 26″ in diameter (nominally a 2″ tyre) and your 29″ wheel is 29″ (which nominally works out to a 2.25″ tyre). If they’re not then you need to adjust accordingly.

Thanks. I’ve always reckoned I’d go single chain ring if they did a 9 tooth cog.
On my 29 that’s a reality with a 34.