Top Tube Bag:
The top tube bags are for extra carrying capacity for longer rides or FS bikes with small frame bags. These aren't feed bags! In some cases, they hold more than the frame bag as pictured on the Specialized Enduro. I think they are a good option if you don't want to resort to a backpack for extra food/gear for multiday trips.
Weight 5-8 ounces. These weigh less than two small top tube bags combined.
These also work well for use with a Dynamo hub. the hydration port is sealed with velcro, which makes running wires in and out painless and relatively water resistant.
these bags have a thin, 1/4", layer of closed cell foam sewn in the bottom.
The fabric is Xpac packcloth, Cordura or Dimension Polyant D40 fabric in silver. Custom colors are available, just email me for options and possible extra wait time. Zippers are #10 YKK water resistant zips.
full rain flaps available, but they do make using the zipper while riding a bit more difficult.
customers have requested other custom details: lash tabs & elastic cord for holding gear/water bottle on the top. zippered mesh or xpac top pockets, lash tabs for SPOT devices.
All are custom built. I will need a tracing of the top area of your bike, with a line drawn showing how tall you want the frame bag to be.