I know this thread hasn’t been active for a while, but in case someone like me is looking for a unicycle backpack and stumbles across it, I’d like to share my experience to help out. Here is my experience with unicycle backpacks:
So far, I’ve tried two different unicycle backpacks: one from QU-AX and one from AJATA. Both were tested with my 20" unicycle, and both are wide enough to also fit my training shoes, clothes, and a bottle of water.
Personally, I prefer the AJATA backpack. The fabric seems better padded and feels more comfortable overall. The unicycle sits very securely inside the backpack and doesn’t wobble enough to bother me. Yes, it can sometimes be a bit annoying to get the unicycle in or out of the backpack, but for me it’s definitely worth it. I use it regularly to travel to my training sessions by bicycle. It feels safe and doesn’t strain me.
In my opinion, the QU-AX backpack has some downsides. The backpack itself is designed for both 20" and 24" unicycles, which makes it feel wobbly when there’s only a 20" unicycle inside. To be fair, I do like the additional space, but I wish the unicycle would moved less inside the bag. Even when using all the internal and external straps, I can still feel the backpack shaking while I am walking. This only stops when I tighten every external strap as much as possible for me, but then the unicycle fork presses against my back, which feels painful after a while.
The cushioned shoulder straps are also very wide and rub against my neck, becoming uncomfortable really quickly. There is no possibility to move them away from my neck because they are sewed immovable to the shoulder strap. I worked around this by folding them and sewing them to reduce their width by half. This helped, but I would still expect better design from a commercial backpack. Additionally, since my legs are relatively long compared to my upper body, the unicycle barely fits into the backpack when the seatpost is extended to my preferred length. The AJATA backpack, on the other hand, has enough space to fit unicycles with seatposts for slightly taller riders.
Lastly, I tried a DIY approach and made my own backpack. I bought a cheap guitar backpack from AliExpress and spent about two hours on the sewing machine attaching pedal pockets similar to those on the commercial models (pictures attached). It fits my 16" unicycle perfectly (with either 72 mm or 45 mm cranks), but there’s definitely not enough space for a 20" wheel. The tip of the seatpost and the saddle stick out of the top of the bag, but that’s no problem for my use case. Fortunately, this solution worked brilliantly, and I use it regularly.
I’d only recommend this DIY approach to people who are comfortable with a sewing machine, as it takes some time and effort, but it’s still much cheaper than commercial products. As a bonus, the guitar backpack even has a nice side handle, which I really like.
