REI Co-op  Junction Seat Bag

The quality of the materials and construction of the REI Junction Seat Bag appear to be quite good, which was expected for an REI-branded product. However, the Junction Seat Bag is almost too big. I transferred everything from my old Specialized seat bag to the REI Junction Seat Bag and there was still a lot of unused space. As a result, the REI Junction Seat Bag was somewhat floppy and the items inside the bag can move around. I would have preferred the items fit more snugly in the seat bag. If I put more items in the seat bag, they would fit more snugly, but I already have a “burrito” bag on the front of my bike where I keep my wallet, keys, snacks, etc. I don’t want to carry additional items just to fill my seat bag. Inside the REI Junction Seat Bag, there is a large mesh pocket sewn on the left side and a smaller zippered mesh pocket that covers the entire inside of the lid. Those two mesh pockets alone hold pretty much everything I carried in my old, Specialized seat bag, except for my spare innertube, which is now the only item in the main compartment of the REI Junction Seat Bag. I considered purchasing the smaller REI Junction Seat Wedge, but it is too small for my needs. The large size of the REI Junction Seat Bag might make it a bad choice for smaller bikes or full suspension mountain bikes. Compression of the rear shock on a full suspension mount bike might result in the bottom of the seat bag hitting the rear tire. I have a 29-inch hardtail mountain bike with an XL frame. When the REI Junction Seat Bag is mounted on my bike, there is approximately 3.5" of clearance between the bottom of the seat bag and the rear tire (see attached photo). My girlfriend has the same bike as me, except with a size Medium frame. On her bike, there is only 1.5" to 2” of clearance between the bottom of the REIJunction Seat Bag and her rear tire (see attached photo). And that’s without the seat bag being close to full. We suspect clearance between the bottom of the seat bag and her rear tire would be even less if she put additional items in the bag. My old, Specialized seat bag has separate top and bottom storage compartments, each with their own zipper. It also has a third zipper that, when unzipped, expands the volume of the lower compartment. I really like those features and wish I could find another seat bag that has them. Unfortunately, Specialized no longer makes the model of seat bag I have. It would have been nice if the REI Junction Seat Bag had a divider inside the bag, dividing it into two storage compartments -- i.e., top and bottom or left and right. That way, items could be organized somewhat and you wouldn't have to remove everything to get to an item at the back of the seat bag. The ability to expand/reduce the volume of the REI Junction Seat Bag, like my old, Specialized seat bag, would have been nice as well. That said, adding those features would presumably have added to the cost and weight of the seat bag. In the end we decided to keep the REI Junction Seat Bag for my XL mountain bike, even though it is larger than I need at this time. We will be returning the second bag because, in our view, it is too big for smaller bikes (in our case a 29-inch hardtail mountain bike with Medium size frame).

I purchased 2 sets of these for myself and my girlfriend (Junction saddle, top tube and bar bag for myself and saddle/bar bag for her) to use on a biking/camping trip. The Good: This bag is an excellent volume for carrying just a little more than most saddle bags without being in 'bikepacking' territory. The light clip and reflective materials are a nice touch and I expected to give it great remarks. The Bad: The construction of this bag is a thin nylon with what feels like foam between the inner and outer layers. Because there is no internal structure to the bag it sags down on the seatpost and the webbing hangers slide forward on the seat rails. During riding it flops around unless it's completely filled with something like a jersey or jacket. Summary: I think the whole Junction line should have the material switched for rip stop which would both look great and add some more stiffness to the bags. The Junction seat bag really needs have some internal structure built into the walls. REI - I'll trade you mine for a V2.0 when this gets updated.

I was looking for something bigger than a saddle wedge to hold phone, airpods, wallet and all my tubeless repair kit I ride with. This bag is a lot bigger than most saddle bags but it isn't bulky. the charcoal color looks clean and it seems to hold up to being water repellant. I squeezed in a pound of coffee beans too on a 20 mile ride and stuffed it in this bag as well. I will keep an eye on the straps as they are cotton thread but as another review said here that can be repaired easily if they are fraying.

I've had this bag for about a year. The size is perfect for me and the body of the bag is quite strong. Its weak point is the attachment of the strap to the top of the bag. It is sewn on with cotton. The cotton has recently begun to fail (see photo). This is not the death of the bag because I can sew it back on again. But it is a warning that I need to keep a close eye on it in future to make sure that the stitching is not failing again. In fairness to the bag, I use it to carry about 1.7kg / 3.5 pounds of tools. I ride my bike way out into the desert and I need to be confident that I can fix most things that could go wrong with the bike. If you carry a more reasonable load perhaps you would not run into this problem. I am only deducting one star because I like the bag very much, because I am asking a lot of it, and because it is, ultimately, repairable.

The bag is spacious, fits well under the seat (my bike frame size is a small, 50CM) and my iPhone ProMax fits in it with a lot of other gear. I ride in very dusty conditions and so the bag gets removed a couple times a week to get hosed off and then reinstalled. There have been no problems with all of this on and off. The overall construction is durable, zippers work well and there are internal pockets; although I do not use them. I would recommend this to anyone looking for a larger under the saddle bag that does not excessively protrude out the back of the saddle.

The pros: I love the size of the bag. I kept tools/patch kit, extra water bottle, back-up glasses, a windbreaker, and back-up mask in this bag for longer trail rides. I liked the color. I like how easy it was to remove/add this bag to my seat. The cons: If you have larger thigh girth, this is NOT the bag for you. The seat post attachment ate thru 3 pairs of leggings & pants. Since cycling/work out clothing is expensive, this is not acceptable. The 3rd time this happened, it ended up not only chaffing my inner thigh but quite literally ripping & shredding the skin. This part should be re-designed so that the end affixes to the bottom of the bag after looping around the seat post.

At $50 I expected this product to last more than 1 yr 2 months and was disappointed when during a ride it broke free (strap frayed, as pictured).

I love this bag. I commute, mountain, and joy ride a fattie. I like the zipper entry. It’s easier than messing with a roll top especially when it’s 10 degrees. It fits my tools, pump, lock, and K9 and human treats. I’ve had problems not clearing the tire because I’m 5’6”. If REI puts out an XL I’m on it.

I love how big this bag is, however, while riding the backs of my legs tend to hit the bag on every stroke.

When I was looking for a 4L-ish underseat bag, I initially took a pass on this because someone else panned the construction. When the same-sized, more expensive Ortlieb bag's mount wouldn't fit my saddle & seatpost, I gave this a try. Not only does it fit, it is way better. The cloth is thick enough, and padding helps it hold its shape when empty. The dual straps for the seat rails make it easier to install/remove than traditional designs using a single strap. A long pocket inside the left wall is big enought to hold a 3-1/4" x 6-3/2" cellphone or -- my favorite -- a hardshell eyeglass case. In addition to the eyeglass case, I was able to insert a 700x32 tube, a patch kit, a handful of tools, and a cycling raincoat (thicker than a shell). The only fault I have found is that the loop for a tail light is placed too low, and my LED light points down about 15°. I may have to resort to using my old Belt Beacon® in low light conditions.