Corsair grabbing her water bottle and facing them is good advice if you have no chance to get away.

Once you are facing it/them, keep facing them, do not turn your back - if there is more than one and they separate from each other, then make sure you have something at your back - even if is just your bike.

The water bottle is a good idea cause if it charges at you, don't throw it, offer the water bottle and dont let go, while the dog has a hold of the bottle, it cant bite you

Wishing you all dog-free roads
RR