Altering and adding zips to gore tex jackets!

[MM-on-POINT]

Has any one ever tailored their jacket or cycle clothes to there needs Before and what happened success or doom?
I have a gore tex jacket (as I'm sure most of us do) which I find fits great but I'm a very hot person and when zipped up it's boil in a bag time, so my intentions is to put underarm waterproof zips in.
I will properly have a local tailor cut and sew for me (unless this can be done by hand) on my chalked in lines and I will seem seal it myself.
I was thinking of undoing the seam that runs under the arm and cutting a slit down the side of the jacket
To have the zip start on the under arm for vent controll
I could put some pics up so you can see and provide comments on, if you have done something similar maybe put a pic up for ideas.
:D

[MM-on-POINT]

Untitled by MM-on-POINT, on Flickr


Untitled by MM-on-POINT, on Flickr


Untitled by MM-on-POINT, on Flickr

My intention is to run a zip along left side where the tape measure is from the top to bottom possibly 60 cm may less. top pic.
Unstitch the seem in pic 2 to attach zip and make a cut from 34cm in pic 3 to 60cm and sew in zip.

it seem simple in theory any suggestion are again welcome

[Ian]

Never done it, but if I was going to try I would study another jacket with some pit zips already installed to see how they've stitched them in. In theory, if you're adding a zip you should have a couple of cm's to play with by the time you've unpicked your other seam.