If you have just a short time in Seattle there is only one way to see the city. Walk at 2.5 miles an hour? I don't think so. Take buses and trams that you have to wait for and that might not even get you where you need to go? No way Jose. Drive your car? Hahahaha get outta here, don't even talk to me. But what about a BICYCLE??? Now that's the ticket. The Bicycle Repair Shop does rentals by the hour or by the day. They have reasonable rates. They have solid, lightweight hybrid bikes so you can tackle train tracks and brick streets and hills. They also have road bikes for the more experienced. You can reserve online in advance. You get a helmet and a lock with your rental. The staff in the shop are friendly and will suggest routes and point out hills if you're new to the area. And believe me these hills are no joke! I had a great time in Seattle and it's all thanks to this business. Next time I visit I am definitely doing this again.
The best type of bike for exercise depends what level of rider you are and whether you would rather ride on trails or on the road. There is a type of road bike that is called a “Fitness Bike,” and features a lightweight frame and narrow tires, but do not have a drop handlebar. This may be the best type of bike for someone who intends to ride regularly and strenuously on the roads. If you plan to do a lot of trail riding, the best bike for exercise would probably be a mountain bike. For a person who uses bikes for transportation and exercise, but doesn’t go off-road, the hybrid bike build is a good type of bike.
Modern bottom brackets use a sealed bearing type construction that keeps water and debris locked out, so they seldom go wrong. Maintenance is impossible so they need replacing when they do wear out. Older style cup bottom brackets need to be re-greased every now and again, and occasionally will need to have their bearings replaced. There are a lot more teeth on the chainring cogs than those on the rear cassette, so need changing less regularly. Cranks usually a solid one piece construction so there is not much to go wrong.