ROCKBROS Bike Frame Bag Waterproof Bike Triangle Frame Bag Reflective Top Tube Bag Large Capacity Black Bike Accessories for MTB, Road Bike

I’ve bought this to prevent me fitting a rack while I go out for loooong rides.....I’m going cycling for a few days and I’m able to carry spare kit and the essentials in this bag. I’ve opted for the 4L version, although initially it fouled on my water bottles, after a bit of tweaking and moving my holders it was a job done good! There’s plenty of room! It’s built really well and fits my bike (XL) great with no obstruction to the legs while cycling. I cant comment on the waterproofing yet but I’m confident it’ll be fine.I’ll update if there’s any issues.So far, A***

Great accessory. Fits neatly within the bike frame. It has plenty of storage

Generally like it, didn’t need the separate compartment on the other side zip but fits well and seems sturdy.

Brilliant product

I bought this bag to carry my e bike battery after converting my bike . A 14Ah battery fits in here perfectly and the 5 straps make it easy to fit . I got it so I could remove the battery from the bike and take in to charge but I've had it attached to the bike on the roof rack at 60mph and it stays secure. This is the 4L bag

For £30 I was expecting something of better quality--the zips in particular seem cheap and very stiff. I don't expect this to be very durable, and is expensive for what it is.

Good bit of kit this. Can hold a surprising amount of stuff (shackle lock, sandwich, flask, jacket, keys and wallet comfortably), doesn’t move about once attached. Easy to install. One side gives you access to the bulk of the bag, the other side is a slip pocket for keys, wallet etc. Haven’t had it out in the rain but you can tell it’ll hold up well in even the most determined downpours. You’d probably get away with submerging it if you had to! Put it on and forget about it.

Good for keeping all your bits and bobs in