Granted, some use commuting to get in some training for racing, a computer makes sense for them. But for those that aren't training for anything, why bother?

I have a computer on my road bike but not on my hybrid. I mainly use the hybrid for commuting and I know how far the distance is, so I didn't bother to get a second computer.

No.

I kind of like to take a photo and make a note on my LiveJournal account whenever I roll over another thousand miles. And I like to keep track of how many miles I got out of a chain or a set of tires. I don't particularly pay much attention to it though. It sits there and does its thing, and I look at it once in a while.

By far the most used things on the display are the clock and the thermometer.

^Yeah, I don't really care about my speed. Most of my miles come on the way home, so I go as fast or as slow as I want.

But I have been thinking about getting one to help plan service intervals at the LBS (don't have near enough tools/knowledge to do everything, yet) or how many miles I get out of a set of tires or chain.

The only thing I'd want to know now on my commuter bike is mileage and a clock. I've kinda given up on watching speed, and I don't even have a computer on that bike.

Besides mileage I just like to know how fast I'm going. When my last computer fizzled out I simplified to a 3-function, $15 computer with an extra $5 wiring kit so I could switch it from bike to bike. The tire diameters are close enough on either bike that I'm satisfied with the accuracy. I don't worry about monitoring speed or mileage on my "family" MTB.

I use one because I'm curious about trip (moving) time / average speed. I generally leave it set to the clock while I'm riding. Mostly so as I'm approaching schools I know whether to be extra cautious due to start of day / lunch / end of day. Since I take a relatively fixed route the distance is typically constant.

I also like knowing the speed, but I've found it can get me in trouble. When I used to see the speed getting "too low", I'd up my effort. Generally going too slow meant I was fighting the wind. Once last summer on my mountain bike during a particularly windy day I really over did it and arrived home completely exhausted. I had trouble walking the next day and couldn't bike for several days.

After having some IT band issues during the summer, I changed my riding style to increase cadence. I wish I had bought a computer with cadence sensor, because I often start pedalling slower without realizing it when I encounter an incline.

these days I use a Garmin 705
I use it in a lot more ways than just a cyclometer

and best yet, there isn't a wheel to calibrate it to

and I use it between all 4 bikes

I absolutely gave up on trying to maintain a given speed on the road bike today. On a local loop, my speed on the upwind leg was about 14 mph; downwind, with less effort, I was cruising at 22-23. It would have been more productive if I had a power meter to watch instead, but I'm not going to spend that kind of money as long as I'm not training for races.

I don't use one very often. I know what my average and top speed is, and I know the distance of all my cycling routes for both commuting and recreational rides. If I was ever going on a multi day touring trip then I would use a computer just to keep track of the mileage.

I had a bike speedometer fifty years ago. It didn't last long.

Paul

I do (but it's not a necessity). I like to track distance and average speed. Most days I ride same pace, but sometimes I like to ratchet it up to see how fast I can complete either leg of my commute.

I mostly use mine for mileage, and as a clock.

I like to watch my averages to track my performance.

Yeah I do. I keep a spreadsheet showing weekly distances etc. Am up to 5000 km this year so far, and will ride all the way through.

It also lets me know when I need to look after the chain and hubs.

Mostly I use it to keep my pace up on the way to and from work. If the number isnt high enough, I go faster.

z

I used to... but my uphill speeds were too depressing. Now I can just focus on getting up the hills and not stress about how fast I do it.

I use mine to track mileage for maintenance purposes.

this

I own 5 roadworthy bikes

I own 1 non-functioning bicycle computer that a friend gave me.

I do maintenance when the bike starts acting wonky.

I've had speedometers since i was in grade 10. 2 mechanical and 2 wired sigmas. The first one was poor, but I had it for 6 years on my old 1 speed Rudge. Then I had a good one on my 1974 + 1989 Raleighs, until 2000. It never failed me and I still have it.

I wouldn't want to go far without one. It's nice to know more or less when I will get to somewhere, or when I am going to be tired. haha Especially on long all-day highway rides. How far to lunch time, etc. I write down the mileage and avg. of my highway trips. The last two bikes i wrote down mileages for the year end and most of my new parts and tires.

I was in 3 asian cities on cheap 1 speed bikes and I didn't have a clue how far it was to the end of the city or my maps.

Besides this, For all my cars and motorcycle, I have kept track of every tank of gas and oil change. etc. I recorded the mileage, price, cost, date and out of town locations. About 10 trips to 31 states.

I use mine daily. I drop the kids off at school at 8:30 (ten minutes before they're supposedly allowed to be there, but I'm far from the only parent pushing the time a bit), and I have to be at work by 9:00. There's a 30 minute ride between the two if I keep my speed at 20+ between the intersections, but if my speed drops by a couple of miles an hour the ride stretches to 32 minutes and I'm late to work. Knowing my speed to within a couple of miles an hour therefore makes the difference between being on time and being late.

The heart rate monitor that's integrated into my computer is mostly just for fun, though.

I'm a nerd. I keep track of everything from speed, distance, average speed, etc.

I want to know exactly how many miles I rode each day, month and year and I want to know what miles were for commuting or off-road.

I'm sure after a few years I won't care anymore, but for now I'm enjoying the stats.

I used to keep track of all data. But now I know how far my journey into work is, I know how long it'll take me on a good day and a bad day. I know my average speed. Not much else to do but watch the traffic!

So I don't use one any more, just like to enjoy the ride

I might put one on in a few months though, just to see how I've improved (if at all!).

Daven