Wattage saving

chippie_chappie

How much would a wattage saving of 8 watts improve my average speed? I've current hot Pirelli Cinturato velo tubeless tyres fitted to my 2017 Felt VR3 with a rolling resistance of 17 Watts at 100 psi. I'm thinking of changing them to some gp 5000 tubeless with a rolling resistance of 8.9 Watts at 100 psi. With the Pirelli it's a real struggle get an average speed above 14.2 mph I've managed 14.7 a couple of times but it's bloody hard work. These low averages are despite achieving a maximum training effect of 5 regularly its always between 4.5 and 5 so I think I should be getting much higher averages for the effort I'm putting in?

brundonbianchi

chippie_chappie said:

How much would a wattage saving of 8 watts improve my average speed? I've current hot Pirelli Cinturato velo tubeless tyres fitted to my 2017 Felt VR3 with a rolling resistance of 17 Watts at 100 psi. I'm thinking of changing them to some gp 5000 tubeless with a rolling resistance of 8.9 Watts at 100 psi. With the Pirelli it's a real struggle get an average speed above 14.2 mph I've managed 14.7 a couple of times but it's bloody hard work. These low averages are despite achieving a maximum training effect of 5 regularly its always between 4.5 and 5 so I think I should be getting much higher averages for the effort I'm putting in?

Don’t use average speed as a primary metric, it’s too easily influenced by things beyond your control / not very good. Use Normalized power. When push comes to shove, you need to upping your power to weight figure, then make sure you’re not wasting any unnecessarily. So minimise the weight of the entire package ( you and the bike, and any kit you’re carrying) then work on the engine ( your fitness, and stamina ). Then work on your position, posture and technique, to maximise the efficiency of the power transfer. Only then do you need to worry about other ( not so significant) things like rolling resistance. Your average speed will increase as a direct result, in given conditions / terrain on given routes. If you start by concentrating on average speeds, you will be peeing in the metaphorical / proverbial wind, as you’re concentrating on things in the wrong order, to make a significant difference. Buying power meters and something with which to read / record the data will be the best money you could spend, if you’re interested / serious about improving your stats.

First.Aspect

http://bikecalculator.com/index.html

About the same as 15C temperature difference, and probably a lot less than wearing winter clothes or hugely less than having a bad day.. or a good day.

Chasing your tail uses up at least 10 W.