I'm the guy who wrote that the tucking excess under works well, but I guess I should have asked directly, how long do you think you need for your use?
Its a bit unclear to me, kinda why I pushed the view that tucking the excess under is ok.
Want to show a photo of your bag on a bike, so its more clear of where you'd be using the straps?
Sure:
The strapping point would be the d-rings on the flap, so nothing too huge, but maybe bulky. Heavy things go in the basket up front. (Not shown above)
And I'm not anti-tuck... more like anti-spending-money-on-length-I'll-never-use.
--Shannon