Mountain bikers need to carry gear- there’s no doubt.
After about 10 years with a gear bag that finally went to pieces I decided to do a bit of research and found the Ogio Endurance 9.0 bag. I couldn’t find this bag anywhere locally so I opted to buy it online. It is a bit pricey with a list price of $160, but you can find it less expensively online through various retailers.
The bag has a wet-pouch zipper compartment on the bottm for your smelly or wet item. It has a zipper end pouch for your helmet. On one end is a zipper compartment which can hold even two pairs of shoes. The center compartment is fairly generous but note that the side compartments do intrude into this area. Each side of the long side also have zipper areas. One of them has a hard compartment to install your phone or Ipod and protect it. The helmet end pouch also includes a hard section to protect other less rugged items when trasnporting.
Finally, one other feature? The carry straps are actually “backpack” straps and you can carry the whole bag like a backpack.
I first used this for travel to the Louisville Worlds Cyclocross weekend. It is NOT a suitecase and if you needed it for several days travel with regular clothes AND bike gear you’d be a bit cramped for space, but for weekend travel it works well so long as you are judicious with your packing and choice of items to pack. But definitely if JUST for bike gear it is a perfect option.