Watts It Worth?


Manufacturers and brands often claim wattage savings but rarely put them in context, such as at what speed and power the savings are calculated at. For a cyclist on a budget I feel the biggest number that matters is the £/watts ratio. Cyclists often spend hundreds or thousands of pounds on equipment that will save them very little watts, but ignore or mock wattage gains that cost very little. To go faster for the same amount of power you can improve your aerodynamics, your rolling resistance, your weight or your drivetrain efficiency. These are the variables within your control. My aim here is to try to put wattage gains in to context and normalise them with the £/w ratio. The table below shows the change, the reported or calculated wattage saving, the cost and the £/w ratio. All values are calculated for a 75kg rider, 8kg bike, riding at 40kph, at 300w power output in typical atmospheric conditions.

WattSavings3

I think this shows quite clearly where the lowest hanging fruit is for cycling performance! Assuming you use your chain for just races and therefore rewax twice per year, you are getting better value per watt than deep section carbon fibre wheels, aero profiled handlebars, ceramic pulley wheels and an aero road bike. To order your WattShop DirtyFast chain just visit the online store.

 

References & Notes:

Any test data was normalised to 40kph. RRPs used for item costs.

Aero road bike: http://pelotonmagazine.com/tested/the-specialized-s-works-venge/

Tyre rolling resistances: http://www.biketechreview.com/tires_old/images/AFM_tire_testing_rev9.pdf

CeramicSpeed: http://www.ceramicspeed.com/sport/products/OSPW

Helmet difference: http://www.dcrainmaker.com/2016/03/specialized-wind-tunnel.html

Castelli speedsuit: http://blog.castelli-cycling.com/2011/11/04/reviews-castellis-sanremo-speedsuit/

Flo Cycling wheels: http://www.flocycling.com/aero.php

Velotoze aero data: http://bikeboard.at/show_bericht.php?ber_id=6197&dsw=1


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