I don't recommend a bike in either city. Part of the charm of Toledo is the labyrinthine maze of streets in the old quarter. Getting lost is half the fun. A bicycle would only get in the way.

Segovia is much the same in parts of the old quarter, although after Toledo, you may feel like the streets are so wide you don't know what to do with yourself.

While in Toledo don't miss the Mezquita del Cristo de la Luz (or capilla, or iglesia...after seeing the architecture, you'll see that it's a mix of three different religions/styles). Tip the gardener for a private tour.

I echo Booklady regarding the Iglesia de la Veracruz. The twelve-sided chapel is unique, and the frescoes are still visible in the interior, although the lye from the centuries has eaten some of them away.

In the front yard of the chapel, you can still see small white, almost porcelain-looking fragments. Those are bone fragments from the cemetery upon which you stand. During the plague years (there was a second plague in the 1500s), so many deaths made it impossible to bury folks inside the church, so they chose the next best place: as close to the church as possible. Ask the curator onsite to recount the entire history. Definitely worth the trip and the extra time investment.

del sol, I would skip the bikes too...in Segovia, you will want to climb the stairs next to the aqueduct at some point, and in Toledo, you'll go nuts trying to navigate small, cobbled streets that are barely big enough for a single car to pass through. There have been many times I have flattened myself against a wall and hoped I wouldn't get hit by drivers passing by! I think a bike is more trouble than it's worth, in both places. I might recommend one in a city like Salamanca, if you were going there--but really, walking is the best way to see both Segovia and Toledo (and remember, both are perched on hills!). They are small enough that you will be able to get anywhere in less than 15 minutes, anyway (though you should budget more time in Toledo because you'll be lost half the time)!

Thanks for the tips. I am so excited about visiting both of these places!

I would consider renting a car and driving from Madrid. We did this last February, going to El Escorial/Segovia on one day, parking in the underground garage at Plaza Santa Anna then driving to Toledo the next. Granted driving the streets of Madrid can be an adventure, but the highways to both cities are fine. We enjoyed climbing the mountain pass between El Escorial and Segovia, and stopping at the ski resort that was there. A very beautiful drive. Parking was not that difficult in either city either. We parked along the streets for free at both. Plus you can make your own schedule and visit as many side places as available such as the Valley of the Fallen, also between Segovia and El Escorial.

We, too liked the advantage and sponteneity of driving but be sure to get good directions to your hotels for either city and go straight there and park the car for the duration of your stay. It's no fun driving around compared to walking, though some of pictuesque hostels that have the "El Grecoesque" views of Toledo aren't an quick walk to town but you can park as soon as you get inside the walls and walk.