Author Topic: Want to go faster?  (Read 1709 times)

Matt2matt2002

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Want to go faster?
« on: May 14, 2021, 07:55:55 AM »
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JohnR

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Re: Want to go faster?
« Reply #1 on: May 14, 2021, 10:41:30 AM »
It's an interesting subject. I wonder what the drag coefficient of a traditional cycling cape is? My main baggage for day trips is a rack bag which isn't discussed but I reckon should have minimal impact on aerodynamic drag. My AHS handlebars let me adopt a slighly lower drag body position when needed but, as I found out only a couple of years ago, drop bars are too uncomfortable.

The biggest factor in the formula is V because it is squared, but it's actually not the bike speed but the effective speed after taking account of the head or tail wind. Cycling at 15 mph into a 15 mph wind results in the drag losses increasing by a factor of four while the 15 mph tailwind reduces, in theory, the drag losses to zero. Crosswinds and associated turbulance also cause extra drag and I suspect that baggage configurations which reduce the head wind losses then increase the crosswind losses. Cycling is much more pleasant on a calm day as the extra effort needed to fight a headwind is never fully compensated by the reduction in effort when there's a tailwind.

steve216c

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Re: Want to go faster?
« Reply #2 on: May 14, 2021, 11:50:07 AM »
Interesting read.

Can someone do measurements with the wind behind me in a non-aerodynamic position to see if that pushes me faster home? Presumably the reverse of those findings is going to be true when I act as a sail? ::)
If only my bike shed were bigger on the inside...

energyman

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Re: Want to go faster?
« Reply #3 on: May 15, 2021, 12:03:22 PM »
You always go faster with a following wind !
Even up hill.

Matt2matt2002

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Re: Want to go faster?
« Reply #4 on: May 15, 2021, 12:53:37 PM »
You always go faster with a following wind !
Even up hill.

My one hill joke:
Climbing mountains are fun. They are hill areas.
Never drink and drive. You may hit a bump  and spill your drink

JohnR

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Re: Want to go faster?
« Reply #5 on: May 15, 2021, 03:26:55 PM »
Going slowly uphill is the one situation when the tailwind boost can be noticeable as the wind is going faster than the cyclist. The drawback is that there's then no cooling breeze into the front of the jacket.