What bad habits in cycling?

[santic]

I think, bobbing the head Up and down by the ears is one of the bad habits.

[Takemusu]

I don’t really mind that so much. Sing while you ride. It’s fine.

Upper body tension; death grip on the bars or grips, rigid arms and elbows locked. Leads to problems handling the bike as well as muscle soreness and even injury.

Relax, damnit.