Is street parking free for motorcycles in Chicago?

I asked this to the Parking Guru from http://theexpiredmeter.com/ and here’s what his expert response was:

Hey Mark!

Motorcycles are treated like any other motor vehicle when it comes to
street parking.

They must pay for parking at metered spaces. However, motorcycles can fit
in a lot of short but legal spaces which are not marked as metered by
signs or not No Parking zones.

And just like if there is free street parking, motorcycles can park for free.

The only advantage motorcycles have is they can park in Residential Permit
Parking zones without having to post an RPP pass for the zone. They cannot
be ticketed for RPP violations.