I needed a Garmin mount to discreetly fit my Edge 25 to my track bike. You're not allowed to see it while riding and I didn't want it distracting others, I searched but found no good options avaliable shop decided to design my own! It is held in place on the back of the seat rails by a couple of sturdy cable ties, the Garmin is then neatly out of the way under the back of your saddle. A few have been in use for a while by myself and some friends and we've had no problems.
Most Garmin computers should fit, a friend uses his 800 with my mount and my 1000 will fit. This particular model fits the Cinelli saddle on my bike and also a Barrelli on my friend's Moda.
I have other mounts that will fit other saddles. Please check my shop.
The angle of the rails is the main deciding factor in if one of these will fit your saddle. If you look at the picture below with arows marke A and B you can see how to find out which one will fit. Wrap 24mm wide masking tape aroundthe rails where the mount would be and draw a line along the highest points to mark the centre. Measure A and B as shown, the difference between the numbers needs to be close to those quoted for each mount. The actual dimensions of A and B don't need to be exact, the mount will just sit slightly higher or lower.
Mount 1: A=61.5mm B=44.5mm Difference=17mm
I have included a template in the images. Just copy it and size it to the width written on it, print it out, fold it and see how close a fit it is.
You will need to source two 5mm wide cable or zip ties to fit the mount.