Ctmcycling

`I’m totally new to road biking. I don’t really understand the speed things and the purpose of the garmins. Can someone inform me on the electronics, what they do, and why I need them. I would really appreciate it.

10 Wheels

Good to track your miles for maintenance needs.

caloso

Depending on what you get, it’ll tell you how fast you’re going, how long you’ve bee riding, how far you’ve gone. If you have a heart rate monitor or power meter, it’ll show that data too. Most GPS units now have maps, so they help navigate. Some will synch with your phone so you can see if have a text or call without having to get your phone out.

Steve B.

Older model bike computers used a magnet in the spokes to count wheel revolutions. That gave you speed, plus time and distance, avg. speed, etc.., GPS units use satellites and can generate same data using position and time moving. Garmins and others also dump the data to an online activity tracker where you can keep track of rides and metrics. Garmins also can be used for navigating a route you create, so gives you turn-by-turn directions in screen. If you are doing an organized ride the route is often available in a digital format where you get TBT info as well as a map of the route,

Bigbus

I use my Garmin to pace myself and compete with my prior rides as far as speed and distance. It also leaves a track, but I never look at that. I do use it for the % grade when climbing or descending a hill too. Oh, let's not forget the time in the corner, or the max speed logged, among many other little features that really don't amount to much except for personal entertainment haha. I might get a cadence attachment for it at some point in the future,

I should add-I spent many years in the field where GPS coords were everything so it kind of trickled down into my civilian life.

Tourist in MSN

You do not need them.

But, if you wanted to know how fast you were going, how far, etc., then they are nice to have. It is basically the speedometer and odometer equivalent to a car.

And if you wanted to pay more, you can get heart rate monitor, speed of your crankset (cadence), maybe a map of where you went and where the roads are, or the ability to take data after a ride and turn that into an electronic track, or maybe to find the best way to get to a specific point from where you are, etc.

Chuck M 

I agree with Tourist in MSN that they are not needed. But they are a cool toy. I use Garmin Connect and Strava to find and create routes that I can use the Garmin to navigate. It is fun and or interesting to look at the data that is collected. And isn't collecting toys for your hobby one of the fun parts?

canklecat

You don't *need* them. But for some of us it helps with motivation.

Some friends who are totally self motivated don't record their rides on anything. No GPS, speedometer, odometer, nothing. They just ride and enjoy it.

But because I was very competitive in my youth I find it helps me to stay motivated when I can compare data from a phone app, computer, etc., over time. Helps put things into perspective when I feel "bad" but the data shows I'm still chugging along just fine. Also helps keep me humble when I feel like speed racer but the data shows I'm very middle of the pack or slower.

Toespeas

the head unit is just like a car , it gives you data , its also very convenient , but some costing 300 plus is just ridiculous and not very practical , you can always use a cheap phone , track your fitness , run navigation to wireless earbuds , play music , never get lost

Iride01 

They record where you were and what your metrics were for that ride. I can look back and see where I went on all my rides since getting one circa 2010.

Makes it a lot easier than having to write it all down and document it by hand.

But if you don't care to know those things then there is absolutely no reason to get one. Only get the stuff for riding a bike that means something to you. Don't think because others use something that you must use it too.

gauvins

I find it useful to distinguish cycling metrics (speed, distance, cadence, power and somewhat related, heart rate) and navigation data (location, course, route, maps).

Garmin is probably the leading name in this business. But there are many alternatives.

Cheapest (and perhaps most reliable) are wired systems. Usually a magnet on your wheel and a sensor on your fork connected to a display on your handlebars. Largely superseded by standard wireless sensors (ANT+ or Bluetooth, often Garmin) sending their bits to a dedicated head unit (often a Garmin), or to your smart phone or smart watch (often Garmin). Numerous configurations are possible.

The vast majority of head units provide navigation data (i.e. GPS), whereas wired systems do not.

You may want to start with a low end wired system to track speed/distance and perhaps cadence, and navigate with your phone. You'll eventually figure out where you want to invest (or not).

njkayaker

Three basic levels of functionality. Each higher level includes the functionality of lower levels).

1- Current speed and data (like cadence). And distance traveled and average speed at the end.
2- Ride history (where you rode and the speed/data at each point).
3- Navigation.

GPS is needed for 2 and 3.

GPS is sufficient for basic speed but a speed sensor is more accurate for instantaneous speed. So, while you don't need a speed sensor with a GPS, you'll want one if accurate instantaneous speed is really important to you. But GPS alone is fine for speed.

Speed sensors work by counting wheel rotations and multiplying the rotations by the wheel circumference.

With an accurate wheel circumference, speed sensors produce very good distance traveled numbers. That means , if all you are interested in is how far you rode your current speed, and an average at the end of a ride, you don't need the expense of a GPS.

GPS units have relatively short battery runtimes. That means they are something you'll need to recharge regularly. If you want history and/or navigation, you'll need to get a GPS unit.

Not all GPS units provide navigation. Not all GPS units that provide navigation provide the same level of navigation. Navigation is better with a bigger screen. Not everybody cares about navigation.

Level 1 devices can last for months on a coin battery and are relatively cheap. They can be wired or wireless. If you opt for wireless, opt for digital.
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John_V 

Pretty much says it all!

Barry2 

I'd never needed a high tech device before I started structured training on my road bike.
Previously I was happy with speed and distance, just out of interest.

With training comes the need for Heart Rate, Cadence, and ideally Power.
All of which are displayed in real-time and logged for future use by the fancy bike computer.

Barry

coffeesnob

i got the garmin edge for my BD I think I will love it. I currently have a specialized cheapo model that works pretty well and is fairly accurate. I dont need either one but we really dont need them in cars either as long as you can read a map.Which I doubt many have ever done.

Tourist in MSN

Njkayaker made a really good point. If you want one just for speed and distance, the older style stand alone bike computers that did not use satellite data are very low power. I have some wired bike computers with coin type CR2032 batteries that last for a couple years. My wireless ones, I might get a year out of the same coin type batteries, but that is a maybe. These count wheel revolutions with a magnet mounted on a spoke and a sensor on a fork or stay.

But, GPS, you are talking hours, not months or years for battery life. Usually those are rechargeable batteries, but some use AA batteries. I use NiMH rechargeable AA batteries in my GPS.

Milton Keynes

I really don't need anything more than using Strava on my phone. I mainly use it to keep track of my miles, though on occasion I'll track my speed if I'm riding my usual route and want to improve my performance. But I'm more concerned with tracking distance over anything else. I do have a speedometer app on my phone but I rarely use it.

bikebikebike

Um
Phones are now the PAN (personal area network) that consolidate the other devices in your world
like it or not
they do the job
BT sensors, and a cell phone do everything you had done by other devices, and do it better.
A cheap Chinese speedo odo , maybe , but is soooo 1980. So was Apple ll.
Get a speed sensor , maybe add cadence , and a cell phone and let Garmin argue with its stockholders about the future.
Buy what you need, not what that market guys want to sell.

sdmc530

Tracking and Training....I mean serious training makes a computer nessasary.

I would not go without my Garmin for either purposes.

Yes my Garmin costs on my bikes (3) is maybe $1000 for everything, for me well worth it!