Randonneur aerodynamics

https://www.renehersecycles.com/journal/

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Monday, March 15, 2021 at 9:22:07 AM UTC-7, AMuzi wrote:
https://www.renehersecycles.com/journal/

I vaguely recall owning a Rene Herse for a short while. It was supposed to be a touring bike but I did not like that ton and a half of metal and changed over to a Schwinn Voyageur which was actually lighter.

On Monday, March 15, 2021 at 11:22:07 AM UTC-5, AMuzi wrote:
https://www.renehersecycles.com/journal/

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971


https://www.renehersecycles.com/aero...ando-vs-racer/

Here is the article you are referencing. What he says makes sense. But it is not a surprise or a mystery or unknown by everyone else. Smaller frontal area makes you more aerodynamic. Which makes you faster. Adding a handlebar bag on front acts as a fairing. And despite the un-aero flat face of the bag, it actually makes you overall more aero because it forms a better shape with your body behind it than if the flat fronted bag was not there at all.

More or less what he is saying in the article is about like arguing whether weight or aerodynamics is most important. Each has a different amount of importance depending on speed and terrain. Going up the hill at 5 mph, aero isn't important. Being 10 pounds heavier probably makes more difference. Going down the hill at 50 mph, I'm not sure if the weight makes you faster going down or the aero makes you faster. Lets pretend the extra weight does. So weight and aero each is a positive or negative depending on other stuff.

On Monday, March 15, 2021 at 5:39:42 PM UTC-7, wrote:
On Monday, March 15, 2021 at 11:22:07 AM UTC-5, AMuzi wrote:
https://www.renehersecycles.com/journal/

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971
https://www.renehersecycles.com/aero...ando-vs-racer/

Here is the article you are referencing. What he says makes sense. But it is not a surprise or a mystery or unknown by everyone else. Smaller frontal area makes you more aerodynamic. Which makes you faster. Adding a handlebar bag on front acts as a fairing. And despite the un-aero flat face of the bag, it actually makes you overall more aero because it forms a better shape with your body behind it than if the flat fronted bag was not there at all.

More or less what he is saying in the article is about like arguing whether weight or aerodynamics is most important. Each has a different amount of importance depending on speed and terrain. Going up the hill at 5 mph, aero isn't important. Being 10 pounds heavier probably makes more difference. Going down the hill at 50 mph, I'm not sure if the weight makes you faster going down or the aero makes you faster. Lets pretend the extra weight does.. So weight and aero each is a positive or negative depending on other stuff.
What would you want better aerodynamics for on a touring bike? Maybe pounding into the wind but the handlebar bag isn't going to help you as much as the pannier hurt.

On 3/15/2021 7:39 PM, wrote:
On Monday, March 15, 2021 at 11:22:07 AM UTC-5, AMuzi wrote:
https://www.renehersecycles.com/journal/



https://www.renehersecycles.com/aero...ando-vs-racer/

Here is the article you are referencing. What he says makes sense. But it is not a surprise or a mystery or unknown by everyone else. Smaller frontal area makes you more aerodynamic. Which makes you faster. Adding a handlebar bag on front acts as a fairing. And despite the un-aero flat face of the bag, it actually makes you overall more aero because it forms a better shape with your body behind it than if the flat fronted bag was not there at all.

More or less what he is saying in the article is about like arguing whether weight or aerodynamics is most important. Each has a different amount of importance depending on speed and terrain. Going up the hill at 5 mph, aero isn't important. Being 10 pounds heavier probably makes more difference. Going down the hill at 50 mph, I'm not sure if the weight makes you faster going down or the aero makes you faster. Lets pretend the extra weight does. So weight and aero each is a positive or negative depending on other stuff.


Much agreed and thanks for cleaning up that link.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 3/15/2021 7:43 PM, Tom Kunich wrote:
On Monday, March 15, 2021 at 5:39:42 PM UTC-7, wrote:
On Monday, March 15, 2021 at 11:22:07 AM UTC-5, AMuzi wrote:
https://www.renehersecycles.com/journal/

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971
https://www.renehersecycles.com/aero...ando-vs-racer/

Here is the article you are referencing. What he says makes sense. But it is not a surprise or a mystery or unknown by everyone else. Smaller frontal area makes you more aerodynamic. Which makes you faster. Adding a handlebar bag on front acts as a fairing. And despite the un-aero flat face of the bag, it actually makes you overall more aero because it forms a better shape with your body behind it than if the flat fronted bag was not there at all.

More or less what he is saying in the article is about like arguing whether weight or aerodynamics is most important. Each has a different amount of importance depending on speed and terrain. Going up the hill at 5 mph, aero isn't important. Being 10 pounds heavier probably makes more difference. Going down the hill at 50 mph, I'm not sure if the weight makes you faster going down or the aero makes you faster. Lets pretend the extra weight does. So weight and aero each is a positive or negative depending on other stuff.
What would you want better aerodynamics for on a touring bike? Maybe pounding into the wind but the handlebar bag isn't going to help you as much as the pannier hurt.


For various definitions of 'touring' maybe.
Randonneurs generally go for bar/set bags, not full touring
cargo handlers.

I would think everyone wants efficiency, at least where
costs are moderate.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Monday, March 15, 2021 at 5:43:50 PM UTC-7, wrote:
On Monday, March 15, 2021 at 5:39:42 PM UTC-7, wrote:
On Monday, March 15, 2021 at 11:22:07 AM UTC-5, AMuzi wrote:
https://www.renehersecycles.com/journal/

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971
https://www.renehersecycles.com/aero...ando-vs-racer/

Here is the article you are referencing. What he says makes sense. But it is not a surprise or a mystery or unknown by everyone else. Smaller frontal area makes you more aerodynamic. Which makes you faster. Adding a handlebar bag on front acts as a fairing. And despite the un-aero flat face of the bag, it actually makes you overall more aero because it forms a better shape with your body behind it than if the flat fronted bag was not there at all.

More or less what he is saying in the article is about like arguing whether weight or aerodynamics is most important. Each has a different amount of importance depending on speed and terrain. Going up the hill at 5 mph, aero isn't important. Being 10 pounds heavier probably makes more difference.. Going down the hill at 50 mph, I'm not sure if the weight makes you faster going down or the aero makes you faster. Lets pretend the extra weight does. So weight and aero each is a positive or negative depending on other stuff.
What would you want better aerodynamics for on a touring bike? Maybe pounding into the wind but the handlebar bag isn't going to help you as much as the pannier hurt.

And when is a handlebar bag a fairing? I'd like to see the wind tunnel experiments on that one. Jan comes up with a whole lot of untested, intuitive truths that conveniently fit his product offerings. 45mm tires are super fast, and 1950s steel frames "plane" and a pre-WW II design crank are the best, particularly when they cost almost $500 in current dollars Okey-dokey. The bag-fairing is $300 f****** bucks. I got a pair of Orlieb panniers on sale at Westernbikeworks for half that. https://www.westernbikeworks.com/pro...ier-set?sg=507 This is bizarre fashion stuff worthy of a Frank Krygowski shout-down.

-- Jay Beattie.

On Monday, March 15, 2021 at 8:00:28 PM UTC-5, jbeattie wrote:
https://www.renehersecycles.com/aero...ando-vs-racer/

And when is a handlebar bag a fairing?

-- Jay Beattie.

I think its fairly obvious the handlebar bag is a fairing in the very specific scenario Jan Heine states in the article. Speeding 50 mph downhill in a very tucked in position where you are able to get your whole body and arms and head behind the flat fronted handlebar bag. Its a fairing in this one situation because it smooths out the whole shape of your body better. But 99.99% of the rest of the time you are riding the bike, its a wind block because it adds lots of extra frontal area besides all the frontal area your body already adds because it is not tucked in behind the handlebar bag.

On 3/15/2021 8:39 PM, wrote:
On Monday, March 15, 2021 at 11:22:07 AM UTC-5, AMuzi wrote:
https://www.renehersecycles.com/journal/

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971


https://www.renehersecycles.com/aero...ando-vs-racer/

Here is the article you are referencing. What he says makes sense. But it is not a surprise or a mystery or unknown by everyone else. Smaller frontal area makes you more aerodynamic. Which makes you faster. Adding a handlebar bag on front acts as a fairing. And despite the un-aero flat face of the bag, it actually makes you overall more aero because it forms a better shape with your body behind it than if the flat fronted bag was not there at all.

This is just a detail, but I've never understood why handlebar bags have
flat fronts. The ones I've mad do not.

I do think the bag aids coasting speed, based on my experience riding
with others.

--
- Frank Krygowski

On 3/15/2021 9:00 PM, jbeattie wrote:

And when is a handlebar bag a fairing? I'd like to see the wind tunnel experiments on that one. Jan comes up with a whole lot of untested, intuitive truths that conveniently fit his product offerings. 45mm tires are super fast, and 1950s steel frames "plane" and a pre-WW II design crank are the best, particularly when they cost almost $500 in current dollars Okey-dokey. The bag-fairing is $300 f****** bucks. I got a pair of Orlieb panniers on sale at Westernbikeworks for half that. https://www.westernbikeworks.com/pro...ier-set?sg=507 This is bizarre fashion stuff worthy of a Frank Krygowski shout-down.

I won't shout, but I'll agree with Jay. As I've said, I think Jan Heine
has done some original thinking that's made sense. But I also think he's
tended more and more to magical thinking that coincidentally matches his
product line. Of course, he'd say he sells it because he's learned it's
best...

About the wind tunnel: In one issue long ago, he did pay for wind tunnel
time. I should dig it out (assuming the guy I loaned it to has returned
it), but the points I remember are that drag coefficient is barely
changeable, so frontal area is the most important thing; and that
(surprisingly) fenders don't impose a significant aero penalty.

But I remember in that issue he attached a bit of cardboard to the top
of a handlebar bag hoping it would send air over the rider in a touring
position - which, of course it didn't. I thought the idea was ludicrous,
and showed that his aero instincts are not very sharp.

However, I agree with Russell that the handlebar bag can be an aid in a
full tuck. My homemade bag is larger than most and less boxy. I've long
suspected it's part of the reason I outcoast so many of my friends.

I recognize that this is in conflict with "drag coefficient barely
changes." More on that in another post.

--
- Frank Krygowski