Any recommendation that measure speed and distance? I prefer something cheap. How does it works?

Almost any bike computer can do speed and distance. You can pick up one at any bike shop.

Most work by placing a magnet on one of the wheels and putting a sensor on the front fork or chain stay in the back.

The cheaper bike computers use a wire from the pickup sensor up to the mount on the handlebars. More expensive computers are wireless so you don't have to mess with the wiring.

These computers require that you set the tire size into the computer to get accurate measurements.

You could pay the bike shop to install it for you.

If you want something fancier, you can get GPS bike computers which don't need a sensor.

Sunding Electronic Bicycle Computer/Speedometer - Free Shipping - DealExtreme

Thanks guys!

If you already have a smart phone, try one of the many free apps to use it as a bike computer.

Regarding using the phone - do you just keep it in your bag and use the GPS for data collection later? If so I assume it kills the battery? My phone's battery goes down pretty fast with GPS on.

If you mount it on the bar, well, I'd be very concerned about it getting damaged physically or by water.

ISTM that spending $5 for a cheap bike computer is far preferable to using a phone.

Depends what you're after. The cheap bike computer is cheap, small, and who cares if anything happens to it? A phone is (or can be) pretty cheap too, but some people have very expensive ones. Anyway, the cyclocomputer will tell you your speed and how far you went, but it won't give you a map of your ride. Maybe you always do the same route and it doesn't matter, maybe you travel a lot or want to explore every road in your city by bike, and it matters. A phone can also be paired with heart and cadence and even power sensors.

Personally I don't use my phone for this, I have a Garmin watch that records a GPS track. Part of the reason is for battery life (mainly for multi-day hikes). I have no doubt my phone's GPS can record for a few hours, though, and that's enough to cover most of the rides I do.

Anyway there are a lot of choices, so probably there's a good one for everybody.

No phone that can act as a bike computer is cheap. If you got it cheap, you're still paying a lot for it, you're just doing it in installments. Break it and try to replace it and you'll find out how much it really cost.

You can get a refurb for $100 or so, that's about as cheap as it gets.

If all you want to do is measure speed and distance with no extra hassle, a wired speedometer is the way to go. Also their black and white screens are very visible in daylight, whereas phone screens are hard to see in daylight, especially direct sunlight. They're also the most accurate, gps tracking can sometimes be a little goofy.

If you want to track your route via gps or something like that though, most old smartphones that people are just throwing out are capable of doing it, even without having cell service. You connect to wifi at home to download the app and upload the route you travelled, and it will do gps tracking on your route. As far as I've been able to tell.

Smartphones have been capable of acting like a bike computer for...I think around a decade? It often isn't hard to find an old one for free, one that would do the job without even having to pay for service. (Note that I tried out one of my old phones on my deck right now and it works well for gps, I haven't tried it out moving around yet.)

I ended up getting a Cat Eye Padrone. No frills and easy to install. A smartphone is horrible and impractical for stuff like this.

it counts wheel rotation , your basic bike computer.. you input the wheel size.

GPS is 3 satellites finding you..

I got a brand-new Android phone for $80. If I break it I can get another one for about $65 now of this model or an updated model for less than $100.

I've got an old one sitting in a drawer I've been meaning to donate. Would gladly hand it to a cyclist if I knew anyone who needed a free GPS phone for tracking bike rides.

You don't need an $800 phone to run GPS for a couple hours.

What do you think of this product?
CatEye Micro Wireless Cyclocomputer

I just bought a cyclometer. I can't figure out the L(mm) for my tire size. The tire size is 27.5x2.10/52-584.
So, what is the L(mm)?

Millimeters? You put a tape measure on the ground, start the tire with the stem at the beginning of the tape measure, and roll the tire forward until you've made exactly 1 rotation. Where the stem ends up is how many millimeters you enter.

Or you could have the bike store install it, that's what I usually do as they're going at having ties and running the cable so it does not get snagged on anything later breaking the unit.

I found a tire size calculator. Not sure how accurate is this. Berkshire Sports - Bike Computer Tire Size Calculator

Definition of cheap is not spending any money. If you have the phone, you can add a bike app for a couple of dollars. You don't need to buy another phone just for a bike computer.

J.

Not sure which measurement you need for your computer. Assuming it's circumference, I prefer the rollout method (or used to prefer, until I moved on to GPS based sports computers). You'll find a description of the rollout method in the page you linked to, scroll down past the various calculators.

--J

Does anyone have any recommended bike computers? I don't know were to start because of the large variety. I would like to spend around $50 any ideas???

I Just bough this. CatEye Micro Wireless Cyclocomputer

It runs pretty good. However, the instruction is a little confusing. I have to read it over a few times to understand on how the functions work and installing on my bike.

Thanks! Ill give it a try!

I've heard good things about the bontrager bike computers. does anybody disagree with this? I've never owned one but i have a friend that has had two of them and he loves them.
What are the pros and cons to these computers?

Thanks!!!

Beyond things you can see from looking at it (some computers have a bigger display, some computers have better controls), as long as you buy something brand name they're all pretty much the same.

I prefer a wired biked computer, have the shop install it and you'll never have a problem with it. Wireless computers seem to need their battery replaced about every 2 years, with a wired computer it runs almost forever and it's just a "don't even have to think about it" thing.

My wife went through three, wireless, Bontrager cyclometers in four months before she gave up, threw it away and went to a Sigma. Every one of them had major issues including resetting itself in the middle of a ride. She's had the Sigma for over two years with zero issues.

Exactly! If you carry your phone with you when you ride, it doesn't make sense buy another smartphone or to have a GPS cyclometer with you as well. All you are doing is duplicating a service that you already have. You can get an excellent phone app for far less (over it's lifetime) than what you can purchase a GPS based cyclometer. The biggest complaint about using a phone for a cyclometer is battery life. You can do Internet searches on how to optimize the battery life of your particular phone. You can also purchase devices from Wahoo (RFLKT and RFLKT+), Cateye (Padrone and Strada Smart) and Topeak (PanoBike) that mount on your handlebars or stem and display the data from your phone so you don't need to keep the screen turned on during the ride. The devices from Cateye and Topeak only work with BlueTooth sensors and their app on your phone. The device from Wahoo works with BlueTooth and Ant+ (iPhones only) sensors and uses their app or several 3rd party apps. They can connect to speed/cadence sensors, heart rate monitors, power meters and BlueTooth enabled trainers.

I have been using my iPhone 5c as my bike computer for over a year now. I have it optimized for battery life and paired to a Wahoo RFLKT+ to use with my Ant+ s/c and HRM sensors. I have done centuries using this combination and still had plenty of battery life left over for emergencies. However, on rides over 80 miles, I also carry a small battery pack just in case I need to recharge the phone. On a 45 mile, daily ride, I normally have 70-75% battery life left over. If you mount your phone in a good quality handlebar mounting system, you don't have to worry about them getting wet or breaking if you fall. I've had several crashes and my phone has never been damaged. The nicest thing that I like about using my phone with a phone app (Cyclemeter) is that I don't have to wait to get home and log on to a web site in order to see my stats and charts from the ride I just finished. It's all in the app.

I have tried several iPhone apps for cycling and have not been impressed with them for basic riding data. First, they all use up a significant amount of battery life. Not a huge problem if you aren't riding far or can recharge frequently, but for me it's a hassle, particularly on long rides. Second, I have found their distance measurements to be less accurate than simple bike computers. Perhaps the GPS on phone apps does not account for the extra distance from riding up and down hills and calculates distances as if roads were level, or perhaps it's because they periodically lose the signal. Third, if you forget to turn them on or off, you don't get any data or useless data. Fourth, I have found the elevation gain data totally useless on every app that I have tried. I bike commute daily and recorded my rides with several apps for a while (Cyclemeter, Mapmyride, Strava), and got widely varying elevation data -- even though I was essentially riding the same route every day.

I use wired bike computers on most of my bikes. Wireless computers run through batteries much faster, and their data often gets thrown off by electronic signals at traffic lights. My wireless computers often show ridiculously high maximum speeds -- such as 200 mph -- usually after passing a traffic signal. Batteries tend to wear out about every 6 months, at least twice as fast as wired computers.