Picking up your average speed

[lukesdad]

Thank You Jimbo I knew what Greg meant.

 

[GrumpyGregry]

I didn't!

Jimbo, you're good at this stuff, what's the maths behind it?

 

[Rob3rt]

http://en.wikipedia.org/wiki/Drag_(physics)

Provides a basic explination.

 

[PK99]

I didn't!

Jimbo, you're good at this stuff, what's the maths behind it?

play around on here for a while. http://bikecalculator.com/wattsUS.html

esp, check out the additional power need to maintain speed as grade (slope) increases

 

[GrumpyGregry]

"the power needed to push an object through a fluid increases as the cube of the velocity". Yikes! I thought it was only the square but then my A levels were a very long time ago.

that calculator makes for some startling numbers from the point of view of the 'lay' cyclist.

fascinating.

 

[PK99]

that calculator makes for some startling numbers from the point of view of the 'lay' cyclist.

fascinating.

yep.a 2% slope (think garden patio sort of slope) requires double the power to maintain 15mph compared to zero grade

or 209 watts fro 20mph at zero grade and a wapping 353 wattts at 2%!

 

[Rob3rt]

yep.a 2% slope (think garden patio sort of slope) requires double the power to maintain 15mph compared to zero grade

or 209 watts fro 20mph at zero grade and a wapping 353 wattts at 2%!

If these numbers are correct, Im not too ashamed of my power output!

 

[al78]

I think my fuelling/hydration strategy needs looking at for runs at a higher level of intensity. I've no idea what my speed in my 20's was; I'd jacked cycling in then to concetrate on playing Rugby.

Are you taking an energy drink and sipping regularly on that throughout the ride? If so, then also consider one of those energy gels and take it about half an hour before the end of the ride (say, 11:15-11:30 ish). I found that helped on the Etape Caledonia (81 miles, furthest I have ever gone in one ride).

Also bear in mind that the intermediates occasionally don't have an official stop so if you have taken food with you hoping for a convenient stop to eat it you may be caught out. An energy gel is convenient here as it can be taken on the move.

 

[GrumpyGregry]

Having tweaked my hydration/fuelling I'm pleased to say I didn't get dropped today. Struggled with one hill just before halfway, then I seemed to get my second wind, though my knee (hairline fracture in January) is sore. Suspect I've overstimulated the nerve that got damaged.

I wonder if I ought to spend more time in the big ring, I seem to be able to churn this more easily than spinning the middle ring.