Review on ROCKBROS Resistant Bicycle Mountain Accessories by Tim Larsen

I use this bag on my Trek FX-2 and am generally happy with it. Three Velcro straps keep it very secure on the top tube and stem. Big enough for your phone, keys and wallet. Because the body is hinged at the leading edge, which fits snugly against the stem, lifting the stem somewhat prevents it from fully opening. Depending on the stem geometry, this may or may not be an issue on other bikes. The only other thing to consider is how a long body like this on your top tube will affect your clearance. If you have a small bike with a short top tube, you may find that a bag like this hits you in a pretty awkward spot as you dismount from the saddle and get on the bike. I have an XL frame with a fairly long top tube and I barely have enough space between the seat and my body to stand on the bike.