In order to save weight I would like to put a carbon road fork on my hard tail MTB frame (which I ride on roads). I reckon if I were to use a fork designed for 650 wheels (triathlon/TT style) but fitted with my existing 26 inch MTB wheels and 26 x 1 inch slick tyres my front end will be lower (too low I think at about 2 inches?).
If I fit a fork for 700 sized-wheels and use a 700c wheel, I think my front end will be about an inch higher.
Can anybody advise which option would give good results and how my steering will be affected? Am I right in thinking the 700 forks will make steering more stable and the 650 forks will make steering more twitchy?
Another related question - I would also have to fit a road brake - would this work with my V-brake lever?
I didn't find the right solution from the internet.
As you already said, a longer fork will slacken your head angle with that slow down the steering. That can feel beneficial but can also feel a little strange. You probably want to check with the maker of the frame if fitting a new and potentially longer fork will affect the warranty.
If you stick to an MTB carbon fork, then (depending on model) you will be able to keep your V-brakes (so no leaver issue) which will outperform road style calliper brakes.