Bushwhacker Mesa Insulated Trunk Bag with Padded Interior – Rear Bike Rack Pannier, Grocery Cooler, Commuter Cargo Carrier, Touring Storage, and Accessories Behind Seat

I bought this bag to bring clothes to work. My ride is 20 miles each way. I have a seat post mounted rack. It is small in size, durable and man does it hold more than I thought. I pack a belt, pair of jeans (rolled), underwear (rolled with jeans), an undershirt, a folded golf shirt and a 12 x 18 small canvas bag in the main compartment. When I get to work I put everything in the canvas bag to bring into the office as I leave the bag mounted on the rack all the time. I pack a pair of socks, a padlock for my locker at work, a thin bike lock, chap stick, deodorate, small bottle of shampoo, wallet, protein bar and a small bag of trail mix in the two side pockets. There is still room for other small items if needed like keys, spare tube, etc if you really want to pack it. My cell phone and work badge go in the top pocket. Only downer is shoes or flip flips do not fit. I leave a pair of shoes at work over the summer, not a deal breaker for me. I have a small under the seat bag for flat repair items so I do not use this bag for those.I have crashed with this on an it did not move/fall off. I do have it attached with ties and a clip though. Someone would need to cut the heavy plastic ties which would be easy with scissors but I'm not worried about that at my office. When out, say a quick stop at 7-eleven to fill up water bottles, no one can just walk up and take the bag. They would need something to cut/clip the ties with. I will just buy another bag if someone really has to steal it from me. The ties do give me that added measure of security that I will never those tit while riding and I can leave it unattended if needed. Attach the ties/clip to the back of your rack from the back loop where you would hang a tail light from.It is also some what insullated. When I pack for the ride to work I have the bike in the house over night, in the A/C. When I get to work on those 80 degree plus mornings, my clothes are not "hot" in the bag which is nice. They are more like room temp. Have not traveled with cold items in there yet. Sides of main comparement are not flimsy.I would buy another one of these if I needed another bag for any reason.

At heart I'm a designer, so am always redesigning everything to improve it.This bag replaced a wood box with thin sides I built for the rack, thus savingone pound of weight.The bag has 4 velcro attachment points, and I added a small piece(3x4 inches) of 1/4-inch plywood in the center of the main compartment insidefastened with a 1/4 inch bolt and two lock nuts through my Avenir rack for security.(be careful when drilling through the bag as the fabric can bunch up on the bit;it would be better to cut that separately before drilling through the insulation)The main compartment is very insulated and its dimensions are: 12 x 5.5 x 5.5.It hinges at the front, the 2 zippers closing the other 3 sides.The two side compartments are 10 x 6 x 2, also zippered.It has a top flat zippered area that I've put a thin book and a map into.The bag comes to within 1/2 inch of the rear of the Avenir rack (which BTW is quite light),so I'd say its dimensions are compact and near perfect and looks nicely proportional on my bike. However it will hold only one gallon water bottle (my 14-inch wood box did 2),so I strapped a 2nd one on top with bungees.A detail is that my large Kryptonite lock does not fit into a side compartment exceptvertically, sticking out 4.5 inches. I imagine a 2-foot Kryptonite chain and small lock would fit.It has a 4-inch strap on the back for a taillight.This is a quality, well-designed bag which I'd say is near perfect. No complaints.Quality is fun.

To be clear, I returned this bag the day I got it, so I cannot speak to durability. I have a very narrow Axiom Streamliner Road DLS bike rack (~2 wide) and the velcro straps are not long enough to attach to it. Make sure you have a ~6 inch wide cargo rack before grabbing this guy.PROS:-In my opinion, it is the only good-looking rear mounted cargo bag on Amazon, especially if you prefer a more classic aesthetic.-Solid construction, not floppy likes some others I have tried.CONS:-Subjective con, the straps are designed to be hidden, and they make the bag very difficult to remove. This bag is not a good option if you want to regularly unstrap it and take it with you.-Related, due to the concealable straps, they are very short, offering no wiggle room for narrower cargo frames.BLURB:This bag is hard to remove and not waterproof at all. Even with those drawbacks I was desperate to make this bag work, solely due to the aesthetic of it. Most of the bags on here are going for a weird neon modern aesthetic, this one had an awesome classic 80s-90s look to it. My bike is an 85', so it seemed like a perfect fit. Alas, the straps are too short for my thin cargo rack... However I can confirm the structure is firm, nice solid base. Tons of room, wish it could have worked!