I've been biking a good bit lately.
I find the Peak Design Everyday Sling bags in both 5L and 10L sizes work very well to carry a reasonable load. The way they're designed, once cinched up for riding, they sit on my back without moving about and make carrying a camera easy. The 5L size fits the Leica M (two lenses, although I usually carry with just one) or the Light L16 easily, with tons of space to spare for a rolled up middleweight cycling jersey, sunglasses in case, iPad Pro 9x7 inch, wallet, keys, AirPods, iPhone, and cycling gloves.
The 10L size fits the Leica SL, I would more usually carry it with one or two Leica R lenses—that's about X1D size for both body and lenses—and similarly has enough room for the other junk as well. I know it can also carry my Hasselblad 500CM with A12 back and 80+50 lenses, but that gets too bulky/heavy for my druthers. (The 10L is big enough to fit the Light L16, my 6x6 pinhole camera, Voigtländer Perkeo II 6x6 film camera, AND my little Sirui tripod if I so desired, although I haven't done that yet.
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I was a little skeptical of these bags at first but have come to appreciate their design quite a lot. The 5L bag has rapidly become my real every-day carry, even when I'm not carrying any camera. The 10L has a better strap design, but I find I can fit the 10L strap on the 5L so I'm thinking of ordering another 10L strap.
(Similarly, the Light L16 is very nice for biking. Small, light, and handy, with a slim/narrow form factor, it runs a long time on a charge, and has enough storage space for many, many photos. It has 256G storage in it; I have 400 shots taken with mine, and it still has over 160G of free space. You can also charge it with one of those USB backup batteries ... I have a small one which will almost bring it back to a full charge from being at 25% power, which usually takes me a week or two to reach from fully charged. Add a light, small tripod like the Sirui T-025X for best stability and it's a pretty sweet photo making machine.)
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