If you ride a lot in traffic it's good to have a bell. And reflective bands and a small blinky front and back even if it isn't nighttime or winter. It can be surprisingly dark on a grey, rainy day. Winter/nighttime - BRIGHT lights.
I just mounted a mirror, a bit early to tell but it saves me from having to turn around all the time. It's not quite stable though and tends to shift when I ride over bumps. I've also seen many riders with mirrors that don't look in them, though, I've come up behind them and their mirrors are askew and useless, or they never glance down at them.
A computer is fun but not necessary unless you're training. Lock - a light one can be handy if you need to pop into a store or something. I don't usually carry a pump or any mechy stuff on my commuter/mtb, I ride places where I can bus or walk home and I rarely flat on mtb tires. On my road bike I always carry a seat bag with 2 tubes and 2 co2 cartridges, plus some spare cash.
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/Selle Italia SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Terry Falcon X
2000 Schwinn Fastback Comp road bike/Specialized Jett
I am amazed at the number of things you ladies can fit on a bike. Forgive me for butchering the terminology here, but I got one of those extenders to add more stuff to the handlebars (don't know what it is called, I call is a dashboard). I also got cross bars (those extra breaks for my road bike) put on, and they are JUST close enough to the stem that I can't add the extender thingy. So until I can fix that, I am doodad-less.
What do you need more handlebar space for? I don't have anything on my handlebars except for a headlight in the winter. My computer is actually on my stem and my mirror is currently in my bar end but I'm working on getting used to one on my helmet to replace it. I don't use a bell - my voice is way louder than any bell and it's much easier to carry.
Both bikes also have road morph pumps mounted to the bottom of the down tube. They also both have two bottle cages. Lastly, under my seat on both bikes are tubes, a multi-tool, a tire lever, pen, paper, lip stuff, a gel and a blinky (on the back of the bag).
My commuter also gets a rack with panniers and fenders and extra rear lights.
My new non-farm blog: Finding Freedom
I have a hand me down cyclocomputer that won't affix to my stem. I have a water bottle holder, but I use a camelbak when I do much riding. I'd like to get a light and attach the computer, but it seems that they don't fit with my crossbars. I have a very very small under the seat bag that I use for my multi-tool, but not much else fits. It is taking some time to figure out what I need and what I can fit. It probably won't happen this summer, but I hope to eventually do a 50 mile ride, and want to make sure I have all that is needed!
This is my first summer biking since I was about 15.
I 've used one of those extender things before. Not so much for the extra space, but to allow my headlight to project beyond my shifter housing. Otherwise, it casts this weird, annoying shadow on the road. Seems to be an issue with my 38-40cm bars, but not with DH's 44 cm bars.