Revelate Designs  Mag-Tank Top Tube Bag

I've had this bag for over a year and love it. I really like the magnetic closure which takes no effort and is easy to do in-ride. It seems to be designed for the front of the top tube, not the rear (under the saddle). If you need a small bag at the rear of the top tube look at the Jerrycan, which is slightly narrower (and smaller). I use it mostly for credit cards/cash and an iPhone 6s, which fits with plenty of room to spare. As Revelate notes on their website, this was not intended to be a waterproof bag -- look at a zippered bag for that, or put your phone in a zip lock baggie and then inside the MagTank. All in all, this is a great high quality bag.

Have only had this bag a few weeks but it’s exactly what I needed. Stays put and out of the way, barely notice it’s there till I need it. I have been using it to store 6-8 energy gels, Alien bike tool, and a couple protein bars. Definitely going to look into getting more products from Revelate Designs because they make high quality gear. The highlight of this bag is the magnetic opening clasp. It’s super easy one handed opening and closing while still being secure, very smart design! Only wish my bike had eyelets on the top tube so I could get the bolt on option for extra stability. Still works great on my Salsa Vaya!

Great bag. Large enough to hold bars, gels, phone, keys, etc., but not too large to get in the way. Easy to open and close while riding. Straps hold it tight to top bar.

I was looking for a toptube bag that wouldn't get in the way and was easily openable. I like to keep my snacks and phone in this bag while I ride so my pockets are empty. It does its job very well. Opening and closing is easy and secure. I can do them both one handed! The waterproofing is also nice. I don't get to take much advantage being in sunny California, but I do pour water on it for fun occasionally and it works well. I was also very surprised by how well this bag stays in place. It doesn't rotate around the top tube while riding. My only complaint is that the lower strap is a little long, so there is a bit that doesn't "hug" the bag and hangs out a bit. My left leg often hits this strap. This can probably be solved by simply cutting the strap, however.

Roomy, big enough for 3 candy bars, the magnetic latch is genius. Does wobble a bit on the top tube.

I love how easy this bag is to open and close! And it holds a surprising amount of stuff (wallet, phone, keys, ID badge, hand sanitizer). My commute involves two toddlers and drop-off at two different preschools, so I'm constantly juggling things. My only problem was that the Velcro strap wasn't long enough for the mighty head tube on my cargo bike, but that was easily Macgyver'd.

I use it to hold a 1300 w front light battery plus spare...as if it were custom made for these batteries, changing batteries is now a snap. And all the extra cable is neatly out of sight. At first it was flopping over and got in the way when standing, but I saw a second position (higher) for the stem velcro, stays perfectly upright using this position. Goes from bike to bike in just seconds...it's the perfect little bike bag

I ordered one for Salsa Beargrease with top mount bolts. Loved it so bought another for my trail bike which does. It have bolts. Seems like the design is slightly different as this one the flap gap is bigger. May just be manufacturing tolerance? Regardless the gap ia rather large and seems like contents will spill out. I got some magnets and glued them in to give additional security on the part of flap furthest away from clasp. Shouldn’t have to fix their design but it’s still a good bag. Just with flaws.

I bought the Mag Tank Top Tube Bag specifically to use as a secure place to put my glasses, sunglasses, and gloves any time that I took them off rather than leaving them behind on a picnic table or bench during my trip, a 600 mile off-road bikepacking trip in Florida. Opening the bag is a one handed operation, and the top with its magnetic, hooked latch closes securely by just by flipping it closed with the fingers. Somtimes other things found their way into the bag ( toothbrush, phone charging cord, floss, a wrapper . . .), but no item was lost. The bag's position just aft of the stem is perfectly out of the way and conveniently in the way when you need it. This is a bag that has no unfavorable points and belongs on every bike.

I've been using this for two types of rides: 1) bike-packing, and 2) shorter local rides where I don't want to take a Camelbak, but want to securely hold my phone and a few other bits. It works great for both (and fits both my phone and mini-pump, whereas the Jerrycan does not). My only complaint is that the bottom portion of the latch is only connected at the bottom, and thus can "fall down" after you've opened the bag. This means that when you then go to close it again, it won't just latch nice and easily as designed. If the bottom part stays up against the bag, then this all works great, but it doesn't often enough for me, that the benefit of this cool one-handed, magnetic closure is often lost. I see no reason that the bottom latch shouldn't be attached to the bag (I suppose it allows a little more flexibility if you really fill this thing to the brim? but still).