I would not want to try riding a bicycle with 80+lbs on my back a full load of ammo and a rifle. Forget firing back I'd be lucky to stay balanced long enough to get down the road without something dropping or falling over.
I'd rather be on a bike carrying heavy stuff than on my feet. If you're moving over a certain speed, you have to actively try and fall in order to topple a bike.
Also of note, that's the 25th ID, Light Infantry. That means that's how they get everywhere. Good old Leather Personell Carriers.
We should like...donate bikes or something.
https://en.m.wikipedia.org/wiki/Bicycle_infantry