maths problem !

[berty bassett]

thank you one and all i just wondered as it felt good and i was bright pink at the end ( always a good sign ) i will try and do the sums myself as a lot of the time i go out and split from the group and go own way so it would be nice to know how to do the sums myself , i dont know if i had pressed stop on 705 then start again when i start on own if it would give 2 rides or just continue where it had left off . but thanks again everybody

 

[berty bassett]

Rasmus is spot on, but I prefer to explain in English rather than Algebraic
I've rounded the figures to 2 decimal places, which causes a small difference between my result and his.

First 10 miles is done at an average speed of 14.8 mph. Time equals distance divided by speed, so the time for this is 0.68 hours.

Total ride is 40 miles at an average speed of 18.4 mph. By the same method as above, work out the total time, and it comes to 2.17 hours.

Now deduct the first 10 miles from the distance total, and the time for the first 10 miles from the time total. Distance equals 40 minus 10, giving 30 miles (duh). Time equals 2.17 minus 0.68, giving 1.49 hours.

So you have covered the last 30 miles in 1.49 hours. Speed equals distance divided by time, so the speed for this section of the ride equals 20.13 mph.

thank you for time taken to explain to an old duffer like me - makes sense now

 

[Rob3rt]

thank you one and all i just wondered as it felt good and i was bright pink at the end ( always a good sign ) i will try and do the sums myself as a lot of the time i go out and split from the group and go own way so it would be nice to know how to do the sums myself , i dont know if i had pressed stop on 705 then start again when i start on own if it would give 2 rides or just continue where it had left off . but thanks again everybody

It would carry on where it left off, you would have to hold the lap/reset button for it to save that ride to the history, then press start to start a second ride.

However the easy way to do this would be to make sure auto lap is turned off, then just hit the lap button when you depart from the group. You will then have 1 lap for the group part and 1 lap for the solo bit, when you upload to Strava or whatever, view the laps tap and look at the average speed for the lap you are interested in.

 

[tmesis]

i cant think of a way other than going in strava and cropping the ride and i dont really want to do that - thanks

You can do it in Strava without cropping your ride. Load up the whole ride, and view the elevation profile that is shown under the map. Position the mouse at the start point you want to measure your average from, click and hold, and drag the mouse rightwards to the end point. Let go of the mouse button and bingo, Strava brings up all the details for just the section you've highlighted. Click the 'Reset Zoom' button to go back to the whole ride.

 

[Cyclopathic]

[quote="berty bassett, post: 2587587, member: 18356"]Could anybody tell me the way to work out this maths problem . I go out for a 40 mile ride - first 10 mile is with someone pottering along chatting with av14.8 then i branch off and do the rest and when i get home the av is 18.4 - whats the formula to work out the average on last 30 . please help as i am sure its an easy sum as soon as i know how to do it , but i cant think of a way other than going in strava and cropping the ride and i dont really want to do that - thanks [/quote]

Not me.

 

[Gixxerman]

Time for total distance (T40) = 40 / 18.4
Time for 10 miles (T10) = 10 / 14.8
Time for 30 miles (T30) = T40 - T10
Speed = Distance / Time, thus speed for 30 (S30) = 30 / ((40 / 18.4) - (10 / 14.8)) = 20.02mph.

 

[Iain M Norman]

Data?
What about enjoying the ride for the ride's sake?

Because it's additional to that. Not in place of.

 

[PhunkyPhil]

I use the below website for calculating different average speeds you can put the figures in any way round you like. Very useful.

http://www.machinehead-software.co.uk/bike/speed_distance_time_calc.html

 

[MickeyBlueEyes]

Data?
What about enjoying the ride for the ride's sake?

I enjoy every ride, well 99% of them. Tracking each one gives me extra drive to commute day after day after day. My enjoyment of cycling is extended when I do a bit of data crunching post ride.

 

[byegad]

Whatever floats your boat, but not for me. I took the speedo's off most of my rides years ago.

 

[tmesis]

Whatever floats your boat, but not for me. I took the speedo's off most of my rides years ago.

I'm not surprised - budgie smugglers on a bike are never a good idea

 

[MickeyBlueEyes]

I'm not surprised - budgie smugglers on a bike are never a good idea

Are they a good idea anywhere ?

 

[byegad]

Speedometer guys!

Never found any Budgie Smugglers that could work for me, now Vulture smugglers...

 

[berty bassett]

You can do it in Strava without cropping your ride. Load up the whole ride, and view the elevation profile that is shown under the map. Position the mouse at the start point you want to measure your average from, click and hold, and drag the mouse rightwards to the end point. Let go of the mouse button and bingo, Strava brings up all the details for just the section you've highlighted. Click the 'Reset Zoom' button to go back to the whole ride.

ooo now thats easy - no maths thanks

 

[berty bassett]

Data?
What about enjoying the ride for the ride's sake?

i do enjoy the ride nearly everytime i go out - but do find it interesting to look at what i do now to what i used to do