Secret Formula for Speed on a Bike (against power)

Aeroweenie.com has posted a large dataset of rider speed vs rider power (see here). From this it is fairly easy to plot speed vs power and excel will even give you the formula

Here it is

Rider Speed in KPH = 14.67 Ln(watts) - 42.4

So now, assuming average weight, CDA, temperature etc you can easily calculate your predicted speed!

ps.
If you know a lot more variables then more accurate speed prediction calculators are available! http://www.aeroweenie.com/calc.html

Cycling Aero vs Weight: All you need to know

Just came across lots of brilliant information on the flocycling website (they make aero wheels). Have a look at their blogs here: http://flocycling.blogspot.co.uk/

From these blogs I have reproduced the following key information! thanks Flo Cycling!

Q1.  What shape is best for bike tubes / spokes /bars (assuming no compromise in weight bearing)

Q2. What is the effect of speed on drag from a bike wheel (aero vs non-aero)

Q3. What is the effect of side wind (yaw into head wind)

Q4. What is the effect of wheels on speed over a long flat time trial /  iron man

 Q5. What is the effect of wheels on speed over a long flatish time trial /  iron man

Q6. What is the effect of wheels on speed over a longclimbing stage

 

Time with "Un-Aero" Wheels Light Training Wheels (1100 grams) : 1:09:46 

 

Time with Aero Wheels FLO 90/DISC (2259 grams) : 1:10:09

Could this be the World's lightest Timetrial (TT) bike at 6.9kg ?

Why do we have to make do with heavy TT bikes? We know that standard line is that weight doesn'tt make much of a difference in TT. Sorry this is pretty much mis-information. Except for downhill and really flat courses bike: weight is usually important. v important if its uphill (as is rider weight). Indeed dropping 10kg will save about 1min of a hilly 25mile timetrial which has an 2000m (0.5% ave) of hills see this link. There is added benefit of a light rider because a light rider is also an aero rider!

Therefore, we have been trying to find the lightest TT bike and this could be it (with slight modification)!

Andreas's linden Canyon Speedmax

see http://andreaslinden.se/2013/07/04/canyon-speedmax-cf-2013/

-----------------------specs----------------------------

Frame / fork: Canyon 
Handlebar: Canyon 
Seatpost: Canyon 
Switchboard Group: Shimano Dura Ace 9070, electronic 11s 
Front: Zipp 808 Firecrest, tube 
Rear wheels: Zipp Super 9 disc, tube (or Zipp 808) 
Tyres: A.Dugast Speed ​​Diamond Silk, tubdäck 
Pedals: Look Keo Blade Aero 
Saddle: Selle Italia Optima Teknologika

-----------------------weight----------------------------

Weight: is currently 7.3 kg with Zipp 808, without pedals

-----------------------modification----------------------------

In fact his current Zipp rear disc weighs 1175g which is not bad but the "DASH GRETCHEN" read disc is 770g 

and similarly the Lightweight-autobahn-rear-disc-wheel is only 780g; so if he fitted that it would be 6.9kg! (but ok it would cost at extra 2500 euros!!)

.......and I just found a pic where someone has done just that

http://www.slowtwitch.com/Products/Markus_Fachbach_s_Canyon_3772.html