I want to put some mini v brakes on a cyclo cross bike to replace the cantilevers that don’t currently stop me at all.

I’ve converted the front with a full length outer.

Is there an elegant solution, other than running a full length outer to the rear brake, for a frame that has no cable stops?

When I did this, back in the day, for a Kona MTB you could buy a collar that went round the top of the seat post. This I think formed a stop

All I can find is this

the thing I had did the same job looked less of a mess and went on the seat post

have you a pic of the current cable run for the canti ?
Used to be a few different designs

Not to hand but it’s similar to the above in that there is a cable stop on the top tube then the inner cable runs to a pipe thqt curves round the seat tube.

You might be able to use a stepped ferrels like this
https://www.sjscycles.co.uk/cables/jtek-stepped-chrome-ferrules-37-mm-insert-for-5-mm-gear-outer-pack-of-4/
With the small end pushed into the small pipe that’s round the seat tube

Or look on the problem solvers website , Ison supply the PS stuff in the uk

Looks like problem solvers backstop is what I need.

Thanks

Full length outer. Drill out the cable guides.