Please don't hate me for replying to an older thread?

My NuVinci requires the 15mm and a 21mm wrench. The manual says to also use an 11mm wrench, but I find it unnecessary as finger tight (for that part) works well. What is the hex key for? Did the older models have a different configuration with the axle hardware? Just curious.

I got my NuVinci to slap on my Surly 1x1 frame, but found out that the welded "hood" on the fork ends makes fitting the 21mm wrench impossible - and you can't use a socket, because of the large flange on that drive side hardware assembly. Technically, I could probably make it work, by micro-turning that 21mm nut, but it's really not practical. I guess I could also grind off the "hood" on that side, but I think I'll pass.

Here's a picture of that "hood" or "lip" or whatever it's called on the Surly Track Ends. It makes the NuVinci virtually incompatible because of that huge nut on the drive side.