How do you know your speed?

[jessmarimba]

I'm too cheap for a bike computer, but I use an app called "RunKeeper" on my phone that will GPS the route and give you minute-by-minute speed estimates. There's a mount to put the iphone on your bars if you want to look at it, or the app will talk to you as frequently as you program it to. I don't know how accurate it is, but I'm not training for anything so an estimate is fine for me.

[Biciclista]

my bike computer is the best invention since sliced bread. I ride better with it! sometimes i find myself poking along and i look down and see i'm doing 10mph and i start pushing a little more. mine also measures temperature, altitude and percentage grade of climb (or descent)
and at the end of your ride, you can always check back to see your maximum speed as well.
If i couldn't afford this one, i would still want the one that just notes speed and miles. it's also a good tool for maintaining your bike (this wheel went 10,000 miles before it had issues.. for example)

[Velocivixen]

I have a Cateye Strada wireless bike computer attached, so I can see my speed. It will tell me also my average and my maximum speed, distance. It also tells me throughout my ride that I'm totally awesome! (NOT)

[Sardine]

I can't help re speed since I generally don't pay attention to that. I use Map My Ride to calculate distance. You can use it to work out how long a route is by entering your starting location then tracing the route to the end point. It will tell you how far it is and also give you information on gradient: http://www.mapmyride.com/routes/create/

[lxb87]

You ladies are all wonderful! Thanks so much for all that info.

I'm definitely going to get a computer when I get my bike. It reminds me of buying a heart rate monitor for going to the gym ... not necessary, but helpful and fun and motivating!

Now I want to plug in some routes to that online map to figure out how long to go next weekend on the rental bike.

[sempronialou]

I use an app on my iphone called GPS lite. I'm not sure how accurate it is, but that's what I use because it gives me my mileage and speeds for set intervals.