Aero wheels

http://www.cyclingweekly.com/news/pr...ynamics-324578

"According to Lew “it’s typical to expect that a tyre with a diameter
2-4mm smaller than the brake track width will be the best aerodynamic
selection based on tyre diameter.�"

"Ballard has combined rolling resistance measurements on rolling roads
with the wind tunnel and explains:

“We see this point to be roughly at around 30-35kph. This is only
important for the front wheel. For this reason, for time trial and
triathlon, we recommend a 23mm tyre on the front and a 25mm tyre on the
rear.�"

How many road bikes are sold with rims with brake track 2-4mm wider than
23 and 25mm? Mine are 18.3mm wide.

--
JS

On Thursday, April 13, 2017 at 1:47:57 PM UTC-7, James wrote:
http://www.cyclingweekly.com/news/pr...ynamics-324578

"According to Lew “it’s typical to expect that a tyre with a diameter
2-4mm smaller than the brake track width will be the best aerodynamic
selection based on tyre diameter.�"

"Ballard has combined rolling resistance measurements on rolling roads
with the wind tunnel and explains:

“We see this point to be roughly at around 30-35kph. This is only
important for the front wheel. For this reason, for time trial and
triathlon, we recommend a 23mm tyre on the front and a 25mm tyre on the
rear.�"

How many road bikes are sold with rims with brake track 2-4mm wider than
23 and 25mm? Mine are 18.3mm wide.

In my experience Michelin's are faster than Continentals. That is probably because their aerodynamicist says that the breakeven point is 35 kph or 22 mph. People rarely go more than 19 mph in sports riding on flat ground.

I actually noticed more difference using Rock and Roll chain lube than anything else. I also noticed a sizeable gain from shaving my legs. I HAD to shave them after I came back from concussion. For some reason my leg hair was so long I had to tuck it into my socks. No ****.

Since shaving and growing back out it remains normal.

On 4/13/2017 3:47 PM, James wrote:
http://www.cyclingweekly.com/news/pr...ynamics-324578


"According to Lew “it’s typical to expect that a tyre with a diameter
2-4mm smaller than the brake track width will be the best aerodynamic
selection based on tyre diameter.�"

"Ballard has combined rolling resistance measurements on rolling roads
with the wind tunnel and explains:

“We see this point to be roughly at around 30-35kph. This is only
important for the front wheel. For this reason, for time trial and
triathlon, we recommend a 23mm tyre on the front and a 25mm tyre on the
rear.�"

How many road bikes are sold with rims with brake track 2-4mm wider than
23 and 25mm? Mine are 18.3mm wide.

It's the next-big-thing apparently: road bikes with ~30mm rims (outside
width)
https://www.youtube.com/watch?v=yrHxQg1OW0A
....and disk brakes...

The /reason/ it's the next-big-thing is twofold:
1) there is a slight aero advantage to be gained, and-
2) the road bike you have now likely can't fit such wide wheels

I'd think there would be a possible comfort gain as well, but that is
hush-hush. Pro and almost-but-not-quite-pro racers don't care about
comfort, only speed.

On Friday, April 14, 2017 at 10:24:48 AM UTC-7, Doug Cimperman wrote:
On 4/13/2017 3:47 PM, James wrote:
http://www.cyclingweekly.com/news/pr...ynamics-324578


"According to Lew “it’s typical to expect that a tyre with a diameter
2-4mm smaller than the brake track width will be the best aerodynamic
selection based on tyre diameter.�"

"Ballard has combined rolling resistance measurements on rolling roads
with the wind tunnel and explains:

“We see this point to be roughly at around 30-35kph. This is only
important for the front wheel. For this reason, for time trial and
triathlon, we recommend a 23mm tyre on the front and a 25mm tyre on the
rear.�"

How many road bikes are sold with rims with brake track 2-4mm wider than
23 and 25mm? Mine are 18.3mm wide.

It's the next-big-thing apparently: road bikes with ~30mm rims (outside
width)
https://www.youtube.com/watch?v=yrHxQg1OW0A
...and disk brakes...

The /reason/ it's the next-big-thing is twofold:
1) there is a slight aero advantage to be gained, and-
2) the road bike you have now likely can't fit such wide wheels

I'd think there would be a possible comfort gain as well, but that is
hush-hush. Pro and almost-but-not-quite-pro racers don't care about
comfort, only speed.

I have a very hard time believing that a step in the tire/rim interface is more aero than a smooth interface.