Florence to Pisa to Lucca and back to Florence in one day

We did it. But we did not climb the tower. It is probably still doable. There is a bus that picks up right by the tower and takes you tp Lucca

You can also use the train. The station you want in Pisa is San Rossore. There is a "dead zone" in the schedule to Lucca from 10:25 to 12:25. Otherwise, trains are every half hour.

In 1989 I did this trip, but in reverse, going from Florence to Lucca, then to Pisa. It remains one of my most memorable travel days, ever. Lucca was great, and I had it pretty much to myself (biking on top of the wall was a real highlight). Then, I got to Pisa as the souvenir vendors were literally packing up, and the marble in the Field of Miracles was lovely in the afternoon light. So, yes, I highly recommend this one day, two city side trip.

It's doable. I would allot more time to Lucca than to Pisa.

A day trip to both Pisa and Lucca is very realitic. I did Lucca then Pisa a few years ago by train, but bus between Pisa and Lucca may be more efficient. I'd suggest spending the morning in Pisa, and then going to Lucca for lunch (several good restaurants to pick from) and an afternoon of activities. There are trains about hourly back to Florence, so you can linger in Lucca if you want. Edit: Also, Lazzi runs a bus from Lucca to Florence (arrives near the SMN train station). It's about the same price as the train and faster when traffic isn't heavy on the expressway.

Pisa has the outstanding Field of Miracles that includes the leaning tower. If you start early, with a car, you should have seen everything you want to see by mid-day. Lucca isn't a favorite of mine. It has a nice brick wall that has been turned into a park/path around town, but the town itself is flat and shouldn't be confused with a hill town. It is better for bikes than hill towns but don't expect anything special.