Street biking- how do I tell my speed?

I recently got back into biking again, maybe a week or two ago and a question has been plaguing me ever since then.

How can I tell how fast I'm going? I've got a 21 speed mountain bike cranked up to the absolute 'toughest to pedal' settings, knobbly tires. The terrain is slightly sub-par asphalt over not-very-level ground, as in a general upwards slant that ranges from about 5 degrees to maybe 30 to 45 degrees. I can always maintain my usual speed, even up the bigger hills, but it takes a bit of effort.

My best guess would be about 15-18mph, but I'm not really too sure.

I've got no money to buy anything that could measure my speed. Too bad there's not one of those big light-up signs around here, that tell cars how fast they're going. ):

Measure the distance and the time it takes you to get there. Then you just have to crunch the numbers i.e. if you were going 60miles an hour your going 1 mile every 60 seconds. I suck at math lol but it shouldnt be to hard. Measure out exactly one mile and time your self then either post it on here or message me and I will do my best to help you figure it out. 

I find its easiest to mark a mile in your car mark your starting point and the end of your one mile point since you obviously do not own the road just use like 6 inch pieces of bright color tape(non plastic) to mark it.

jump onto mapmyride.com

map your ride and enter how long it takes you, it will then calculate your average speed for the ride. great site, try it out

google maps is an awesome tool. I use it all the time to calculate my run distance, from there I can get my speed.

Hope that helps!

If biking is going to be a regular form of exercise for you and you want to use speed to gauge progress/effort, an inexpensive bike computer might be the way to go.  You can pick one up at a bike store for around 20 dollars or so, nothing fancy, just one with a speedometer and odometer (I always like to know how far I go and also keep a running tab of distance).  But for now the other posters gave you some great ideas.

I would second just using google maps it will give you your exact distance and then just check your watch to see how long it takes you.

15-18 is pretty fast for non-asphalt and knobby tires. I average about that speed on my road bike on a smooth surface..maybe even a bit slower on long rides.

I second the computer if you can swing it. They are fairly inexpensive. The cycling trails around here are marked with mile markers, so it makes it easy to determine distance/speed.

Oh man, thanks y'all. Google maps helped me figure out where a mile was - great suggestion btw - so it was easy enough to time from there.

It took about 3.5 minutes to go the mile, maybe a little bit more. I had to subtract time 'cause I overshot my mark. XD; Whoops.

That's.. a bit more than 16mph, just by guessing. Maybe 17? Correct me if I'm wrong.

I'll certainly be using that mapymyride site next time I go out. Ty!

Formula is pretty simple:

a min - b mile

60 min -x miles

x= 60*b/a

UD

I'm just starting biking (outdoors) as a form of exercise. I have a 3 yr old (46 lbs) and a 10 month old (18 lbs) in a bike trailer behind me. I'm wondering if lugging the extra weight burns more calories or if its all the same?

Thanks to other posters that offered up great links! I'm going to check out mapmyride now!

A speedometer/computer is the way to go.  You can get one on eBay very reasonably....from $5 on up.  http://shop.ebay.com/items/_W0QQ_nkwZbicycleQ 20speedometerQQ_armrsZ1QQ_fromZR40QQ_mdoZ

Check the various brands out at the bike shop first.

I think you will like it.  Sometimes the measuring provides extra motivation.

Original Post by nenebug:

I'm just starting biking (outdoors) as a form of exercise. I have a 3 yr old (46 lbs) and a 10 month old (18 lbs) in a bike trailer behind me. I'm wondering if lugging the extra weight burns more calories or if its all the same?

 

Thanks to other posters that offered up great links! I'm going to check out mapmyride now!

As with other things it's hard to answer generically. It really depends on the terrain, is it hilly or flat, how fast you are going, etc.

UD

Original Post by nenebug:

I'm just starting biking (outdoors) as a form of exercise. I have a 3 yr old (46 lbs) and a 10 month old (18 lbs) in a bike trailer behind me. I'm wondering if lugging the extra weight burns more calories or if its all the same?  

I would say that you definately burn more calories towing a trailer.  (With all other things being equal).  You not only have more inertia to overcome when you start, but you have friction from four wheels instead of two, and you have a lot more wind resistance from the trailer.  Going uphill would burn even more calories as you are having to pull more weight.  I can usually sustain 20mph+ without my trailer, but I can barely do 16 with it.   

I learned the hard way about the uphill with the trailer part today! I felt like I had more of a workout then when I bike alone. Thanks to everyone for their answers!