Silvio front-chainstay aero mods?

tiltmaniac

Zen MBB Master
Just curious if anyone has thought about or attempted front-chainstay aeromods for the Silvio?
The flat carboyoke is about the worst aero profile one could have...

If I had time to play with it (playing with other things, like trike stuff), I'd probably attempt to improve the aero there. On the non-drive side, there is nothing that would prevent up to a factor of 20x drag reduction (flat vs aerofoil drag in air is ~26X the drag) for that piece...

If I were making it, I'd make it out of some foam, so that it could flex, and then wrap (or shrink) some lightweight plastic around it and the chainstay. The front part would be shaped like a 'D', and the rear part mostly like a 'V'.

Am I the only one who has thought about this?
 

ratz

Wielder of the Rubber Mallet
Am I the only one who has thought about this?

Yep; then I remember that I can ride that bike at 25mph without effort, and if I want to go fast I get on the vendetta, at that point I stop worrying about it....
 

MrSteve

Zen MBB Master
You're not alone.
If I owned a Silvio, it would be modded... but I don't.

My Sofrider's round tubes have been faired, from time to time, with carved foam and tape.
No longer, as it only added a little more free top-speed for a lot of extra ugly.
Try rear discs on your rear wheel.
That is worth doing.

Your reclined body, faired head and tight clothing help a lot more than a faired carboyoke.

Oh, and young, trained legs.
 

MrSteve

Zen MBB Master
One more thing:
I don't know about you, but sometimes, while looking at the pedals, I fantasize about how much cooler
they would look and how much faster the bike would be if only the soles of my feet were faired.
Hey, it's been done!
Records have been broken!
I could do that too!
But it'll never happen, because just one unfortunate slip when starting could end up ruining my day.

In other words, it's likely that you're thinking about your carboyoke because you can see it
all the time.

The discs on your rear wheel will split and fair the turbulence that your bike generates and
it'll eliminate the drag your spokes impose.

But, don't listen to me.

I wanna know how much faster you are with your faired carboyoke than you are with your stock bike!
 

super slim

Zen MBB Master
Guys, I am a SLOW rider, and only cruze at 25 kph(16 mph) on the flat.
Would disk covers on the rear wheel increase my speed by 1 kph? or 0.1 kph
 

ratz

Wielder of the Rubber Mallet
Guys, I am a SLOW rider, and only cruze at 25 kph(16 mph) on the flat.
Would disk covers on the rear wheel increase my speed by 1 kph? or 0.1 kph

Nope; but they'd make you look faster.

Aero benefits for bursting really don't kick in until you get above 18mph and then when sustaining speeds at or above 21mph is when it becomes huge. That's part of the reason Larry is testing so many things for his records attempt. At those speeds everything counts triple. Now in addition to speed you have to factor in wind. In our neck of the woods when the winds blows 15 and you are riding straight into it at 17mph that's 32mph sustained and it makes a big difference
 

super slim

Zen MBB Master
So on a 60 miles out and back ride today, only averaging 11 mph, with 25 mph headwinds, in BOTH directions with gusts up to 35 mph on the outward trip and 43 mph on the return trip, would a rear disc wheel help?

Is there a way of limiting the Garmin Edge 800, with a silicon cover +- 3% grade change on a flat road for 25 to 35 mph gusts, and +-5% grade change on a flat road for 25 to 43? mph gusts?????
I have tried blocking the silicon cover slot to the air pressure sensor to no avail!
 

MrSteve

Zen MBB Master
Yes, of course any aerodynamic aid will be helpful in a 35 to 54mph gale.
I like my rear wheel covered anyway. The covered wheel makes me feel more stable on the bike.
 

tiltmaniac

Zen MBB Master
Nope; but they'd make you look faster.

Aero benefits for bursting really don't kick in until you get above 18mph and then when sustaining speeds at or above 21mph is when it becomes huge. That's part of the reason Larry is testing so many things for his records attempt. At those speeds everything counts triple. Now in addition to speed you have to factor in wind. In our neck of the woods when the winds blows 15 and you are riding straight into it at 17mph that's 32mph sustained and it makes a big difference

When I'm commuting to work, there is a stretch here I consistently go 27 for a particular stretch on the way into work, but 22-23 on the way home from work in that location.
There is a 1% or less than 1% grade, but the headwinds are really the big deal that slows you down.

@MrSteve How does a covered rear make you feel more stable? I'd feel the opposite!
 

MrSteve

Zen MBB Master
When I'm commuting to work, there is a stretch here I consistently go 27 for a particular stretch on the way into work, but 22-23 on the way home from work in that location.
There is a 1% or less than 1% grade, but the headwinds are really the big deal that slows you down.

@MrSteve How does a covered rear make you feel more stable? I'd feel the opposite!

Here's the story, the way I remember it....
Curious about disc wheels, after having done a lot of online research, I decided to mock-up some cardboard wheel covers
for the back wheel.
Not for the front wheel: while testing handlebar mounted fairings on motorcycles in the Central California valley,
I'd get blown all over the lane sometimes.
So, just for the back wheel.

With my cardboard wheel covers in place, I rolled down the hill in front of the driveway,
the hill I'd rolled down daily, for years.
It made a difference.
My bike picked up speed faster, reached a slightly higher top speed and rolled out much farther.

On the road, my average speed picked up a little and bombing downhill was much more scary/fun.
Surprisingly, the wheel covers stabilised my Sofrider: instead of being blown sideways by
wind or by the slipstreams of the big trucks, my bike would lean into the wind.
Like a tailfin on an aircraft, the rear wheel covers were compensating for the side-loads imposed by the wind.

The cardboard covers lasted about a week on the road.
On a long, fast downhill stretch, one side disintegrated and sort of scared me a lot.
The paint on the swingarm still shows the marks.
I made more permanent covers out of 1/4" expanded polystyrene insulating panels -foam boards-
and those work well for me.

As yet, I don't have enough seat-time in the Vendetta to make any claims about stability one way or the other,
but I'm a believer and they're a standard feature on my bike.
 
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