Campa 11spd in 126mm Spaced Frame?

Quick query here:

Simply, given a 126mm spaced rear end, can I, even if it involves cold-setting to 130mm, comfortably fit an 11spd campy set-up in there?

Yes but only if you move the dropouts farther apart.

126mm = no hubs made that take 11 cogs

Okay cool - I was pretty much accepted on the fact ill cold set the dropouts at 130mm, but wondered whether clearance on the inside of the chain stay was at all a problem, but evidently not.

Cheers Señor Bear!

It very well might be. Your question didn't ask that.

Quite: 130mm has been the standard since 8 speed, but squeezing increasing numbers of sprockets into the same space has required an increasing amount of inventiveness.

I believe the bottom 11 speed sprocket is now cantilevered over the hub, so I wouldn't be surprised if there has been some jiggery-pokey at the other end.

An 11 tooth top sprocket would be more likely to clear the stays, but even then you might not be able to use the full length of the dropout, ie it might only work with the wheel set all the way back.

No need to cold set immediately, if at all: just wrangle it in and see what's what.

Let us know how you get on.