With all the stops, cycling is usually faster unless the route is uphill or you really don't have a lot of stops and probably need more.

Maybe I'm just a dumbass, but I think your rule of thumb is busted?

X should be slower than A, but should not be faster than A + B.

Isn't slower the same as "not faster"? I think it should be slower than A, but faster than A + B. So between A and A + B.

Or "the bus should be faster if it's already here, but cycling should be faster if you'd have to wait for the bus". I think that's what you were going for.

My rule of thumb is that within a city, a bus (other than BRT) is likely roughly the same speed as a bike, assuming good bike routes.

If the bikes are stopping regularly because of red lights, that will obviously change.

Its a good rule of thumb. I ride an hour in to work (on an e-scooter) because it is faster than that bus during rush hour. Outside of rush hour though, the bus beats me every time. It'd be cool if I could become mayor to add a bus lane for that route. And all the other routes that need it tbh.

if a bicycle is slower than a bus, then it is definitely slower than waiting+taking a bus

Bike with parking can and often should be faster start to destination than walking+bus+walking at least compared to city buses, it’s different with buses who are allowed to go faster than 50 km/h