dfroelich wrote:
Super D wrote:
... PR'd a few segments with a standard road helmet and kit and no aero wheels. I took it easier than my training ride on Thurs, NP that day was 263, and today NP was 250, yet I avg'd .8mph faster. Interesting... Next, going to get back on the fit rig with the measurements from this new setup, and will tweak fore-aft saddle position and look at power numbers, and also find out if there is anything else that needs attention.
Everything is looking good, but I am skeptical that such a change could make sure a radical difference.
You mentioned: 13 fewer Watts and 0.8mph gained. Plugging in arbitrary numbers: 25 vs. 25.8mph, you sped up about 2s/km. (Lower speeds: 20&20.8mph would be about 5seconds/km saved.)
I forget the full 'aero rule of thumb', but a quick search say 10W = 1s/km
...so, is it possible that your tweak saved roughly 33W (20W for the speed increase + 13W for going 13W easier)? Any way you could show some before/after pictures from the same angle? If that is a legit 30W+ aero savings, I'd love to see it!
(Disclosure: my math is often terrible, but I think I got the mph/kmph conversions correct. Don't yell at me if I made a stupid error.)
After I reconfigured the entire cockpit, I thought to myself that I should probably have taken a photo of me on the bike first and afterward, LOL. I’m an idiot.
Being pragmatic, there are several factors which may've affected the outcome, wind direction and how that bolstered speed in certain sections, and other things such as the amount of sleep I had, where I was in the recovery cycle in training during the week, temperature, HR, tire pressure, lots of things. I guess at a high-level just not going slower was an indicator that things are going in the right direction. But I can’t really read into the rest of it too much until I do a controlled test on a fit rig with the power meter, so I can discern what the net effects were on power output and efficiency in the pedal stroke (combined with some aero improvements to net a potential speed gain at lower power). For now, it’s just fun experimentation. :D
I would never question, ridicule, or complain about anybody’s mathematical computations on this forum. That would be suicidal! :-)
P.S. Looks like somebody snapped a pic of me in my new aero position on Sunday's test run!
