If you are planning on going on a multi-day ride or just riding a long distance in a day, you should have something for first aid, just in case. Unfortunately, almost everyone who cycles frequently will go down at least once in their life. This kit can be really small and compact and can include bandages, some gauze, and a small bottle of a disinfectant.
Basic first aid supplies: A few bandages of varying sizes. 6 Aspirin, or other OTC painkiller of choice. A few alcohol pads in sealed foil packs, useful for cleaning grease off grease and grit off of the bike, and also cleaning cuts on yourself if you take a spill. 1 day supply of any prescription drugs you need to take regularly. Wrap these up in tinfoil and tuck away. It might just save your day.
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.
As you mentioned, it is surprising how often you can get multiple flat tires on while riding, particularly on longer sprints. The tip about bringing a patch kit in your bike repair kit can be incredibly helpful if you’ve already had one flat tire. I agree that all you listed seems like an awful lot to carry, but it’s always better to be safe than sorry, isn’t it?
Pedals are important because the serve as the contact point between the rider and the bike’s transmission. Clip-less pedals systems come in a variety of designs favoured by individual manufacturers, but the mechanics of all styles are roughly the same. Tiny adjustments in the position of the show cleat – that snaps into position on the pedal – can make a big difference to the comfort and health of the rider.