A bit of Knowledge is a Good Thing! As you can see I have been doing some thinking about my bike ie should I upgrade and were exactly the 3kg savings are made that $3000 can get me.
Turns out about 2kg of it will be in the frame and components and 1kg in the wheels of which 400g is in tyres and tubes alone!
I started looking into bike resistant forces to see the affect of dead and rotating mass (yes I know mass is best out of the wheels but being an engineer i wanted to understand things better) and I found a calculator from Analytic Cycling that included tyre pressure in calculating rolling resistance and found rolling resistance increased compared to 120 psi for 90 psi and 60psi by 2.5% and 5% respectively. A friend of mine Gray recently questioned my choice of running 110psi .... Hmmm ... perhaps there is something in this ...
My approach has been ... hmmm this is hard enough and go ride but this morning I pumped the tyres just prior to departure (both were hard but 60 psi!). But wait there is more
I also looked at my seat height (suggested by Annette) and used the fit calculator from Competitive Cyclist which gave me some crazy numbers but that might have more to do with the sloppy measurements I made ... but it did recommend something higher.
I did raise my seat by 4cm above my old rule of thumb method of the heel on the pedal.
It did feel much better from a quick test ride and with the correct tyre pressures I think the two improvements helped me drop 30 minutes off my best riding time on a ride from Cronulla down to Bald Hill and back sort of proved it. I don't think I have amazingly improved by 10% with no training!
The sad part of this story is that it means until something breaks I cannot justify a new bike :>
Thanks to my friends for prompting me to understand things better :>
Turns out about 2kg of it will be in the frame and components and 1kg in the wheels of which 400g is in tyres and tubes alone!
I started looking into bike resistant forces to see the affect of dead and rotating mass (yes I know mass is best out of the wheels but being an engineer i wanted to understand things better) and I found a calculator from Analytic Cycling that included tyre pressure in calculating rolling resistance and found rolling resistance increased compared to 120 psi for 90 psi and 60psi by 2.5% and 5% respectively. A friend of mine Gray recently questioned my choice of running 110psi .... Hmmm ... perhaps there is something in this ...
My approach has been ... hmmm this is hard enough and go ride but this morning I pumped the tyres just prior to departure (both were hard but 60 psi!). But wait there is more
I also looked at my seat height (suggested by Annette) and used the fit calculator from Competitive Cyclist which gave me some crazy numbers but that might have more to do with the sloppy measurements I made ... but it did recommend something higher.
I did raise my seat by 4cm above my old rule of thumb method of the heel on the pedal.
It did feel much better from a quick test ride and with the correct tyre pressures I think the two improvements helped me drop 30 minutes off my best riding time on a ride from Cronulla down to Bald Hill and back sort of proved it. I don't think I have amazingly improved by 10% with no training!
The sad part of this story is that it means until something breaks I cannot justify a new bike :>
Thanks to my friends for prompting me to understand things better :>
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