At first I needed a smaller bag which would replace my pannier during one day trips. I have a rack mounted in my vintage Gazelle Randonneur Trophy all the time – in this case I see transverse saddlebag as superior over saddlebag in classical shape.
I thought about buying Carriadice bag, but they use cotton duck which is to heavy for my taste
My cycling setup would gain weight instead of loosing it, because pannier in same size is lighter.
I decided to make my own bag of Cordura which saved 400 grams without sacrificing functionality. Finally I also added few useful features as additional bottom strap with buckle (yes, I am using buckles wherever it's possible), which makes attaching my bag to rack very fast and makes luggage more stable. I added a handle, now there is a way to catch the bag in less than a second – no need to attach shoulder strap every time...
I also made a QR mount which works with all my saddles. It has adjustable mounting width and added some “distance” (some saddles have their rails hidden you need some kind of a spacer).
As I made my new MTB bike with dirt drop I thought about getting some cages for front fork. The problem is when you have suspension front fork /or you don't want to carry them all the time (and make our bike heavier ~400 grams forever ;((( ). For these reasons I designed my QR polycarbonate cage, which can work with suspension front forks or forks with eyelets.
HERE you can see my stuff in action:
https://www.youtube.com/watch?v=4bljg1glyzg
Feel free to share your thoughts about it and ask any questions.
I am planning to start a crowdfunding campaign with saddlebags in two sizes and the cargo cage and if you like my bag you'll be able to get it.
If you want to learn more about bag you can visit Indiegogo webpage by 
