I had picked this up as a gift for my friend and here's his review of the same:

"The Viaterra Fly Magnetic Tank Bag is a reliable and versatile accessory for motorcycle enthusiasts. Its sturdy build quality and magnetic mounting system ensure a secure fit even during high speeds and rough terrains. IMO, this tank bag is a must-have for both daily commuters and long-distance riders. Overall, the Viaterra Fly Tank Bag is a top-notch storage solution that enhances the riding experience and keeps belongings organized and protected, and I am very happy using it for both city and highway purposes. "

Been using this on my MOJO 300. Very solid build quality. Magnets are like Monitor Lizard hold (உடும்பு புடி). Satisfied with the purchase.

The magnets are solid as it mounts in 4 places. Even on the off-roads the tank bag doesn't move a bit. With a fully loaded bag or partially loaded - the bag maintains its integrity. Side zipper pockets are small when compared to its competitors. EBC net is beneficial for holding onto gloves, paper tissues, and snack packs. The part I love the most about the tank bag is the shoulder straps and the inner mesh pockets. External Rain liner does its job of protecting the contents of the bag.

Review – ViaTerra Fly Magnetic Tank Bag
Bike: Honda CBR 250R
Order No. #31888

I Bought this bag for the tank mounting as well as to use maps while riding my CBR. Quality of the bag is superb and I have used it in several trips. Its convertible to be used as a backpack too. Capacity is great for carrying daily office stuff or a long weekend ride. For longer rides I used this tank bag along with my Claw (72L). Highly recommended to all bike lovers. I have been using this bag for daily commute as well. I would say VIATERRA is good when it comes to quality. I am very happy with the purchase, I really liked the quality of this bag and material used is too good. It’s really worth for our money. The build quality of fly magnetic tank bag is very good and has various other compartments so that I can keep and manage my all important documents safely. It’s stable in high speeds more than 120 Kmph and it's does the job very well.

I would suggest VIATERRA would provide GREEN color rain cover for more visibility.

Sathish,
Chennai

I have been using the fly for quite a few months now and I personally feel this is the right time for me to provide a user review.

To be frank I haven’t really used Fly as my main luggage carrier. It has always been the secondary and with that it works really fine.

Mostly the stuff that I have in the Fly would be my rain liners both top and bottom, basic tools of my bike, chain lubes, micro fiber cloth and a portable tyre inflator and my wallet in the side pocket Ofcourse and a plethora of first aid kit in the mesh compartment. So, I guess now you understand how handy it becomes as a secondary luggage.

Will list out the pros and cons 1st and will elaborate on each of them shall we.

Pros:
1. Build quality
2. Sturdiness
3. Magnets
4. Size
5. Reliability

Cons:
1. Size
2. Pullers
3. No dedicated rain liner compartment

Build quality:
Have to say this is really a well built tank bag. The moment you touch it you can feel the fabric as a sturdy one that’s ready to take quite a lot of bashing.

No doubts that this bag will serve you many many years.

Sturdiness:
In this new iteration the addition of that plastic sheet to maintain the form is a simple yet brilliant idea.

Having that as a detachable item is classy. I generally keep it inserted though. Really helps to pack things in an organised way. And also helps to use the zippers in one hand easily.

Magnets:
The 5 magnet design is a charm and I have no complaints with them. Once fixed on the tank, the bag stays that way even after a 500km ride.

Its a worry free bag and you can confidently keep it on your tank and forget about it.

Size:
18L capacity feels right on my CBR250R. Not more not less. Helps me grab my clip ons without intrusion and due to the size and form factor, the bag really doesn’t intrude when am having fun at the corners.

Reliability:
As i had quoted before, the material feels really sturdy and as a overall package, this bag oozes quality.

With proper wash and maintenance am sure you can use this bag daily even over 5+ years. Plus Via’s excellent customer service and option to repair the bag for damages is something remarkable.

Now, time for the cons.

Size:
Surprised? You should be. As i said, the size feels adequate. No more no less.

But if you see the items that i had listed, they’re not much and for that itself the bag feels full.

May be that’s also another reason why I don’t feel like using the fly as my main luggage. May be Via could have used the option to increase the storage a bit by loosening the zippers like they have in their non magnetic model.

Pullers:
Come on via. You and Rynox are like the Apple and Samsung of the travel gears segments.

You can get inspired from them when they do something right. Right?

Adding pullers to the zippers would have helped using fly even easier while wearing gloves.

Rain liner compartment:
You have 2 side pockets and you fill one with the bag’s rain liner? Seriously? Come on. Even bags that cost lesser than Fly has a dedicated rain liner compartment so it doesn’t eat up space.

You could have followed the same and could have intelligently used the bag’s top layer for rain liner storage.

Overview and verdict:
If you have read this much from the beginning, then i would say you’re pretty serious with your purchase and you’re at the right place.

All the cons mentioned are nit picks and they’re not gonna hamper your user experience in any way.

But the pros, they’re gonna be with you for a long time. If you wanna buy a tank bag and don’t wanna have second thoughts after purchase then this is the bag to go.