I really like this bag! It's nice to be able to just use the top portion for small items, but when you need to carry more stuff, the sides fold out, offering a ton of storage. Being able to remove the bag with the push of a button is great as well. I had originally ordered the strap on version, but it didn't work for my application. The crew at thebikesmiths.com answered all of my questions and made the return/exchange very easy. I highly recommend this bag and thebikesmiths.com