Camera in your tank bag?

I'm retiring at the end of the month and heading south for a 3 month meander across North America. I've got a fill sized Canon DSLR, but am thinking about getting something smaller that takes up less space in the tank bag. What have folks had good experience with?

build your own?

I put my camera bag (D750/70-200/2X converter/and a mid-range zoom (camera side up) in the side bag of my '16 R1200RT. Prior to that I would put a backpack on that had a custom piece of foam to hold the prior Nikon and the zoom in place. I would also strap a monopod to the side of the backpack.
I would not recommend that for long rides - so I'm stuck without a monopod when I take the two wheels.

The custom foam was bought from 'Building 19' and was, I suspect, for making pillows. I used a carpet cutter to cut in into shape - first getting it to fit into the backpack snugly then to cut out areas for the camera and spare lens.

I imagine a tank bag of the right size, you would be able to do the same type of thing.

I have several Canon DSLRs but I carry a Panasonic GX8 in my tank bag. I like the m4/3 size for travel.

I bought a Panasonic lumix DMC-FT5 so I wouldn't have to carry my Nikon DSLR. It has become my go to camera.

Panasonic Lumix DMC- ZS series. My old one is a ZS9. Voni has the much newer ZS50

Sony RX100. This camera gets high marks from photography enthusiasts. I also have a little 4 ounce Lumix ZR1 that I just carry in my chest pocket. Pretty convenient.

Mike Oughton, the author of many excellent trip reports on ADVrider, (MikeO), really likes the Canon S100.

Have a look at the dpreview site if you want detailed reviews of any cameras.

I have carried a Canon 7D Mark II and medium zoom or 70-200mm in the tank bag on my GSA with extra lenses easily accessible in my top box many time. Trying to figure out what to do on my K1600 now since the tank bag is smaller. Maybe a 24-70mm. If I want to go smaller, I have a new Canon mirrorless, a M5. It has a 17-150mm on it and packs small and I have an adapter to use my full sized lenses. This trip I want the 7D though, but will be using the M5 for many other trips.

Every day camera.

When I leave my DSLRs at home, I carry a Canon G1X MkII with a Canon 270 II flash, a GoPro Hero 5, and my iPhone 6+. Don't take up much room or weigh much. Works good. My great granddaughter and my dog, straight from the G1X MkII with a little flash.