as a trainer and student of dog behavior...I would suggest:

Directly confronting a dog who is genuinely aggressive can be risky and
unless you feel pretty sure that you're able to "own the space" with a calm, and certain "knock it off" it might be a better idea to--as most of you already know-- get off, keep the bike between you, stay very calm, keep your SIDE to the dog, fake a yawn and move away slowly.

In other words, send calming signals and refuse to play chase me, or who can yell the loudest.

You guys are right about the chase...in 90% of the cases, nothing to chase, game's over.

And better to learn to read dog body language than rely on nose length...

elk