Hi all. Thought I'd share my build since I've been really happy with the result. There is a TL;DR at the bottom.
Firstly, my commute to work involves walking from my house to the train station, catching a train and then riding my bike that I store at the station to work. Same in reverse for the way back obvs. The bike lives in the station lock up box and at work only. It never goes on the train.
There are 3 things I need to carry on my commute: Laptop,a nice shirt for work and my battery for what I call my town ebike.
I picked a hard shell box off the shelf that would fit all of those items from an automotive store that is full of foam and stuck one of topeaks quick release mtx track thinggys as well and 3d printed an extra bit of slide track.
The whole thing when loaded does weigh a fair bit when I'm walking to the station with the battery but once I'm on the bike, the laptop has a great amount of foam support from the box foam. I've been doing this commute now for about 2 years and the Laptop is still working fine.
I'm only making this post now after 2 years because I've just had to remake my shoulder strap. I used cheap ali express clasps the first time round which was a huge mistake. A strap clasp broke and the box dropped from my waist height onto concrete with the battery and laptop both inside. Both survived the drop without issue. You can see the impact zone of the box in one of the pics.
I made the new bag strap out of cheap paracord because that held up fine but used some clasps from a boating store made from ss316. There are also ss316 lashings on the box to secure the strap.
The topeak quick release slide track system works really well and I haven't had a single issue with it over the last 2 years. Super chuffed with how quick and easy it is to attach and detach the box to the rear bike rack.
The whole thing has gone really well until the strap breaking but now it should last longer with the new one. Took so long to weave it though lol.
TL;DR I retrofitted a box with some extra bits, it holds all my stuff and attaches to the bike really well. I'm super chuffed with it.
by timorpatty