Do you use an fairing or partial fairing on your ebike, emoped or BSM?

General Discussion about electric bicycles.
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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by SafeDiscDancing » Jan 18 2022 12:48am

BalorNG wrote:
Jan 18 2022 12:31am

Chalo wrote:

"Low center of mass impairs both maneuverability and control, because... "

And he explained why.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by MadRhino » Jan 18 2022 12:50am

Low COG makes balance precision
High COG makes balance reaction

I always use the extremes to illustrate this principle: GP racing motorcycles that have the highest COG, and Trial motorcycles that have the lowest COG.

GP bikes need to be balance reactive, meaning little action from the rider is required to initiate a change of trajectory. At low speed or standing still, a GP bike is a PITA because of balance instability. Nobody can keep a GP bike standing still very long before having to land a foot on the ground. Walking a GP bike, one need to hold it with both hands and be careful not to lean it because it does quickly fall off balance.

Trial bikes need to be precise, meaning a wider action amplitude from the rider is required to initiate a change of trajectory. At high speed a trial bike is dangerous because it does lack the reactivity required for quick maneuvering. Anybody with some training can keep a Trial bike standing very long before having to land a foot. Walking a Trial bike, one can hold it negligently with one hand because it does need to lean much more before falling off balance.

Clear enough ?
Try it yourself.
Make it fool-proof, and I will make a better fool.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 12:51am

SafeDiscDancing wrote:
Jan 18 2022 12:48am
BalorNG wrote:
Jan 18 2022 12:31am

Chalo wrote:

"Low center of mass impairs both maneuverability and control, because... "

And he explained why.
I have zero problem with that. Not *stability* though, but to restate the obvious 'stability and manueverability is negatively correlated'. What works for motogp will not work for a touring bike.
What's your notion with bike roll axis NOT being the ground though?

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 12:55am

MadRhino wrote:
Jan 18 2022 12:50am
Low COG makes balance precision
High COG makes balance reaction

I always use the extremes to illustrate this principle: GP racing motorcycles that have the highest COG, and Trial motorcycles that have the lowest COG.

GP bikes need to be balance reactive, meaning little action from the rider is required to initiate a change of trajectory. At low speed or standing still, a GP bike is a PITA because of balance instability. Nobody can keep a GP bike standing still very long before having to land a foot on the ground. Walking a GP bike, one need to hold it with both hands and be careful not to lean it because it does quickly fall off balance.

Trial bikes need to be precise, meaning a wider action amplitude from the rider is required to initiate a change of trajectory. At high speed a trial bike is dangerous because it does lack the reactivity required for quick maneuvering. Anybody with some training can keep a Trial bike standing very long before having to land a foot. Walking a Trial bike, one can hold it negligently with one hand because it does need to lean much more before falling off balance.

Clear enough ?
Try it yourself.
Are you absolutely sure that supposed high CG of a motoGP bike is a design choice, not an (undesired) consequence of other design contraints?

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 12:59am

calab wrote:
Jan 18 2022 12:46am
Argument from authority https://www.dailywire.com/news/watch-be ... nk-berrien
If you want to take issue with the argument I would urge you not to use the argument from authority, which is: somebody has a PhD by their name they know what they’re talking about. That’s a dumb argument.
Argument from authority does not count as an argument indeed :lol:.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by SafeDiscDancing » Jan 18 2022 1:09am

BalorNG wrote:
Jan 18 2022 12:55am
Are you absolutely sure that supposed high CG of a motoGP bike is a design choice, not an (undesired) consequence of other design contraints?
That's what I've been trying to tell you and it appears the other guy just explained it better.

And the terms get confused here.

When I say "Handling" then I mean "Reactive".

"Stable" is the inverse of "Handling".

A quick handling MotoGP race bike is purposely made to maximize quick directional changes by exploiting a higher center of mass.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 1:20am

SafeDiscDancing wrote:
Jan 18 2022 1:09am
BalorNG wrote:
Jan 18 2022 12:55am
Are you absolutely sure that supposed high CG of a motoGP bike is a design choice, not an (undesired) consequence of other design contraints?
That's what I've been trying to tell you and it appears the other guy just explained it better.

And the terms get confused here.

When I say "Handling" then I mean "Reactive".

"Stable" is the inverse of "Handling".

A quick handling MotoGP race bike is purposely made to maximize quick directional changes by exploiting a higher center of mass.
Ok. How about you describe a mechanism how does one make balancing and steering corrections on any bike, high or low CG - does not matter, so we, indeed, clear confusion in terms?
I do not claim to understand every aspect of singletrack dynamics (Vittorio Cossalter I'm not), and I'll gladly internalise any new model if it seems better than one I currently have - but you are not making it easy with what amounts to condescension trolling.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by SafeDiscDancing » Jan 18 2022 1:32am

BalorNG wrote:
Jan 18 2022 1:20am
I'll gladly internalise any new model if it seems better than one I currently have - but you are not making it easy with what amounts to condescension trolling.
Fair enough.

I thought MadRhino made an interesting point about Trials bikes in that they are purposely designed to go the other direction and locate the center of mass very low.

So the recumbent has more in common with a Trials bike than a MotoGP bike.

In MotoGP you have these incredibly high speeds (220+ mph now) and they need to get the bike slowed under insanely hard braking and then in an instant flick the front wheel outward from the intended turn direction to generate maximum counter steering force.

Think of that front tire... it is brutally slowing down... then in probably a second has to take the contact patch and direct it so that the center of mass is essentially dropped off a cliff.

Now if the rider screws up and times his inward steer too late then he might wash out the front with a low side.

But if he times it too early he won't get the lean he needs and that will force his line to go wide and he likely will crash on the exit of the turn.

There is a moment where you are effectively "floating" before you "land" into your full lean.

All this happens at really high speeds and pressures.

Stability just means you are "slow" and will be last in the competition.

Anyway... do you see that?

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by ebike4healthandfitness » Jan 18 2022 1:46am

BalorNG wrote:
Jan 18 2022 12:55am
MadRhino wrote:
Jan 18 2022 12:50am
Low COG makes balance precision
High COG makes balance reaction

I always use the extremes to illustrate this principle: GP racing motorcycles that have the highest COG, and Trial motorcycles that have the lowest COG.

GP bikes need to be balance reactive, meaning little action from the rider is required to initiate a change of trajectory. At low speed or standing still, a GP bike is a PITA because of balance instability. Nobody can keep a GP bike standing still very long before having to land a foot on the ground. Walking a GP bike, one need to hold it with both hands and be careful not to lean it because it does quickly fall off balance.

Trial bikes need to be precise, meaning a wider action amplitude from the rider is required to initiate a change of trajectory. At high speed a trial bike is dangerous because it does lack the reactivity required for quick maneuvering. Anybody with some training can keep a Trial bike standing very long before having to land a foot. Walking a Trial bike, one can hold it negligently with one hand because it does need to lean much more before falling off balance.

Clear enough ?
Try it yourself.
Are you absolutely sure that supposed high CG of a motoGP bike is a design choice, not an (undesired) consequence of other design contraints?
:lol:

I seriously don't even know how you can write this stuff Balor.

If MotoGP designers made the bike with a low center of gravity it would be like a cruiser....great for crosswinds but not for changing direction quickly.

I can't believe this topic still goes on and on and on even though we had 10 pages and the people trolling about low center of gravity hurts stability clearly lost.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by SafeDiscDancing » Jan 18 2022 1:51am

ebike4healthandfitness wrote:
Jan 18 2022 1:46am
I can't believe this topic still goes on and on and on even though we had 10 pages and the people trolling about low center of gravity hurts stability clearly lost.
MadRhino wrote a very easy to comprehend post that seems to have resolved all the confusion.

And I actually did not know that about Trials bikes so I'm learning new stuff too.

Makes me want to try riding one it might be a totally new experience.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 2:25am

SafeDiscDancing wrote:
Jan 18 2022 1:32am
BalorNG wrote:
Jan 18 2022 1:20am
I'll gladly internalise any new model if it seems better than one I currently have - but you are not making it easy with what amounts to condescension trolling.
Fair enough.

I thought MadRhino made an interesting point about Trials bikes in that they are purposely designed to go the other direction and locate the center of mass very low.

So the recumbent has more in common with a Trials bike than a MotoGP bike.

In MotoGP you have these incredibly high speeds (220+ mph now) and they need to get the bike slowed under insanely hard braking and then in an instant flick the front wheel outward from the intended turn direction to generate maximum counter steering force.

Think of that front tire... it is brutally slowing down... then in probably a second has to take the contact patch and direct it so that the center of mass is essentially dropped off a cliff.

Now if the rider screws up and times his inward steer too late then he might wash out the front with a low side.

But if he times it too early he won't get the lean he needs and that will force his line to go wide and he likely will crash on the exit of the turn.

There is a moment where you are effectively "floating" before you "land" into your full lean.

All this happens at really high speeds and pressures.

Stability just means you are "slow" and will be last in the competition.

Anyway... do you see that?
Yea, I understand all that.
What I do not understand why swinging bike CG (that is intiated from contact patches that you admit yourself) is *easier* the higher it is... larger lever - harder to swing, that is kinda obvious, right?
It is not at all apparent from your (more poetic than technnical) description of what is going on.
What you elaborate further?

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 2:43am

SafeDiscDancing wrote:
Jan 18 2022 1:51am
ebike4healthandfitness wrote:
Jan 18 2022 1:46am
I can't believe this topic still goes on and on and on even though we had 10 pages and the people trolling about low center of gravity hurts stability clearly lost.
MadRhino wrote a very easy to comprehend post that seems to have resolved all the confusion.

And I actually did not know that about Trials bikes so I'm learning new stuff too.

Makes me want to try riding one it might be a totally new experience.
Actually he didn't.

The whole 'walking the bike' premise is nonsensical because MotoGP is simply much, much *heavier* than a trials bike, therefore if you lean it the same way as trials bike it will try and lean harder, even if it had lower CG - which it might or might not have, but walking the bike is simply not an argument.

Are there any actual numbers regarding CG of motogp and trials bikes and why exactly designers chose one over the other?
Again, there is a perfect reason why a motogp bike cannot be extremely low - it must lean 60+ deg to negotiate corners at close to 2g, and if you put the engine and bodywork close to ground you'll scrape it and go down - this is why riders has to lean OFF the bike and scrape their knees instead, something that just does not apply to bikes/bicyles mere mortals ride.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by ebike4healthandfitness » Jan 18 2022 2:58am

BalorNG wrote:
Jan 18 2022 2:43am
SafeDiscDancing wrote:
Jan 18 2022 1:51am
ebike4healthandfitness wrote:
Jan 18 2022 1:46am
I can't believe this topic still goes on and on and on even though we had 10 pages and the people trolling about low center of gravity hurts stability clearly lost.
MadRhino wrote a very easy to comprehend post that seems to have resolved all the confusion.

And I actually did not know that about Trials bikes so I'm learning new stuff too.

Makes me want to try riding one it might be a totally new experience.
Actually he didn't.

The whole 'walking the bike' premise is nonsensical because MotoGP is simply much, much *heavier* than a trials bike, therefore if you lean it the same way as trials bike it will try and lean harder, even if it had lower CG - which it might or might not have, but walking the bike is simply not an argument.

Are there any actual numbers regarding CG of motogp and trials bikes and why exactly designers chose one over the other?
Again, there is a perfect reason why a motogp bike cannot be extremely low - it must lean 60+ deg to negotiate corners at close to 2g, and if you put the engine and bodywork close to ground you'll scrape it and go down - this is why riders has to lean OFF the bike and scrape their knees instead, something that just does not apply to bikes/bicyles mere mortals ride.
Remember this picture?

Image

Here is the story behind it.

(Read it. The difference in performance has nothing to do with clearance of the bodywork.)

https://www.cycleworld.com/story/bikes/ ... ead-myths/


"In 1984, Honda brought its first NSR500 to Daytona, built in approved low-CG style with the fuel tank slung under the engine and the exhaust pipes (which are mostly empty space) routed over the top with the rider protected from their heat by an insulated dummy “tank.” Honda was funding a French group that was applying Formula 1 concepts to bikes. Very exciting.

The new NSR’s problems didn’t appear until later in the Grand Prix season, when rider Freddie Spencer noted that it was sluggish in direction changing on twisty tracks. A test was laid on, consisting of a slalom course made with traffic cones. The rider would ride the slalom at successively higher speeds until he began to knock down some cones. Baseline was the best slalom time Spencer could achieve on last season’s three-cylinder NS3, a fast-maneuvering bike. Both bikes were tested with full fuel. When Spencer entered the cones on the new bike at the NS3′s highest entry speed, the bike knocked down the cones; it could not be manhandled through the direction change as quickly as the triple.

Next, they removed all but a quart or two of fuel from the new bike’s underslung tank, and added roughly 35 pounds of lead weights above the engine, simulating a full top-mounted tank. This time, the new bike went through the cones just as quickly as had the triple.

Why? Engineers had imagined that as a bike rolls in changing direction it is pivoting on a line through its two tire footprints. If that were true, putting the fuel on the bottom would make it easier to pivot because it would be swinging through a shorter arc than if it were up on top of the engine, farther from the ground.

But that’s not what happens. At one track I could stand and watch bikes coming straight toward me, then turning right. In light rain I could see the trace of their travel as a line on the track. As the riders countersteered to their left to make their bikes flick to the right, the tire footprints moved to the left as the tops of the bikes tilted to the right: They were rolling, not around a line connecting the tire footprints, but around the center of gravity of bike, fuel, and rider, which is about 22 inches off the pavement. They were pivoting around their roll axes.

Seen in this way, the slalom test result makes sense. Putting the fuel under the engine moved it farther from the roll axis, creating more resistance to the motion. Putting the fuel back above the engine reduced its distance from the roll axis by roughly half. No wonder fuel tanks in MotoGP have been changing their shape, growing a “foot” that extends back under the rider’s seat, where the fuel’s mass is right on the roll axis."
Last edited by ebike4healthandfitness on Jan 18 2022 3:01am, edited 1 time in total.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 3:00am

MadRhino wrote:
Jan 18 2022 12:50am
Low COG makes balance precision
High COG makes balance reaction

GP bikes need to be balance reactive, meaning little action from the rider is required to initiate a change of trajectory. At low speed or standing still, a GP bike is a PITA because of balance instability. Nobody can keep a GP bike standing still very long before having to land a foot on the ground. Walking a GP bike, one need to hold it with both hands and be careful not to lean it because it does quickly fall off balance.
To elaborate it furhter, the fact that a motoGP bike is *resistant* to rider 'body english input' due to its sheer mass and cannot be effectively 'track standed', does not by any means imply that it is more 'reactive' - same with, say, huge touring bicycles like Honda Goldwing or something.
It simply means that it is, indeed like a recumbent (a argument that I have myself made a few times), *must* be balanced with steering first and foremost, you do not have 'body english' to fall back to when things get gnarly.

And for same reason the playground of recumbents AND motoGP bikes is nice, smooth asphalt with plenty of traction - with exception of *some* recumbent designs that, unfortunately, no longer recumbent.

So far I'm not impressed.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 3:10am

ebike4healthandfitness wrote:
Jan 18 2022 2:58am
Remember this picture?

Image

Here is the story behind it.

(Read it. The difference in performance has nothing to do with clearance of the bodywork.)

https://www.cycleworld.com/story/bikes/ ... ead-myths/
Now THAT is very interesting! So, things are indeed more complex than I think, and seems like it takes a huge article written by a lifelong professional to hammer the points home...
I'll need time to digest this.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 3:23am

"Next, they removed all but a quart or two of fuel from the new bike’s underslung tank, and added roughly 35 pounds of lead weights above the engine, simulating a full top-mounted tank. This time, the new bike went through the cones just as quickly as had the triple.

Why? Engineers had imagined that as a bike rolls in changing direction it is pivoting on a line through its two tire footprints. If that were true, putting the fuel on the bottom would make it easier to pivot because it would be swinging through a shorter arc than if it were up on top of the engine, farther from the ground.

But that’s not what happens. At one track I could stand and watch bikes coming straight toward me, then turning right. In light rain I could see the trace of their travel as a line on the track. As the riders countersteered to their left to make their bikes flick to the right, the tire footprints moved to the left as the tops of the bikes tilted to the right: They were rolling, not around a line connecting the tire footprints, but around the center of gravity of bike, fuel, and rider, which is about 22 inches off the pavement. They were pivoting around their roll axes.

Seen in this way, the slalom test result makes sense. Putting the fuel under the engine moved it farther from the roll axis, creating more resistance to the motion. Putting the fuel back above the engine reduced its distance from the roll axis by roughly half. No wonder fuel tanks in MotoGP have been changing their shape, growing a “foot” that extends back under the rider’s seat, where the fuel’s mass is right on the roll axis."


Ok, I definately need to think more about it and how that applies to more pedestrian designs than motogp... I still do not really understand how a 'roll axis' of a bike can be something other than a "line intersecting contact patches" - which it might indeed be a mistaken view, but sertainly need time to 'switch my models'.

"For me the final nail was the discovery that sometimes braking distances are shorter if a bike is made taller. As a bike accelerates from one corner to the next, its tires cool significantly, losing some grip. If the rider just pulls the lever at his/her braking point, the cooled front tire may lack grip and slide or lock. But make that bike just a bit taller, increasing the brake-induced transfer of weight to the front, and the extra load makes it grip.

Most road and street riders wisely do not ride at a level that brings all of the above into play, but it does partly explain why powerful sportbikes are built as tall as they are, with higher riding positions than in the past. The rest of the explanation, of course, is that today’s much grippier tires allow lean angles that were impossible 20 or 30 years ago. That requires engines and footpegs to be placed higher to allow cornering clearance.


All in all, just like keep implying, handling of bicycles and motorcycles is a complex mishmash of multiple conflicting factors and which one would be the winner depends on balance of OTHER factors, so without understanding of dynamics down to 'every odd-shaped brick' taking one 'well-known fact' and applying to an other, different scenario doesn not guarantee it will work well...

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 3:34am

Ok, once you know which question to ask (which, as they say, requires knowing at least half the answer), there are even more interesting articles:
https://www.motorcyclistonline.com/blog ... wing-line/

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by Cowardlyduck » Jan 18 2022 3:43am

Come on guy's....feel free to contribute to the discussion of the actual thread title "Do you use an fairing or partial fairing on your ebike, emoped or BSM?"
If you want to discuss centre of gravity stuff maybe make a new thread about that.

There is a guy in/around my area in Canberra that rides a recumbent with just the tail fairing. Like this:
Image

I've chatted to him a few times and he reckons the tail fairing has a greater impact than a front facing one. From my limited understanding of aerodynamics I think he's right.
Makes me wonder what kind of tail fairing I could cobble up out of solar panels. :mrgreen:

Cheers

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 5:08am

Cowardlyduck wrote:
Jan 18 2022 3:43am
Come on guy's....feel free to contribute to the discussion of the actual thread title "Do you use an fairing or partial fairing on your ebike, emoped or BSM?"
If you want to discuss centre of gravity stuff maybe make a new thread about that.

There is a guy in/around my area in Canberra that rides a recumbent with just the tail fairing. Like this:
Image

I've chatted to him a few times and he reckons the tail fairing has a greater impact than a front facing one. From my limited understanding of aerodynamics I think he's right.
Makes me wonder what kind of tail fairing I could cobble up out of solar panels. :mrgreen:

Cheers
Yea, and for once the discussion about steering turned to be actually fruitful!

Back to the fairings - most certainly, tail fairings have much more potential than front fairings, because is it tail portion of the fairings is what doing the actual work of 'pressure recovery' - providing a *push* to the bike by converging the air and compensating for the leading edge stagnation point. Also, being away from front wheel, they should affect the *steering* directly much less compared to front fairing, even with much greater lateral area.

HOWEVER, que some 'shape drag coefficient' pictures from this article:

https://en.wikipedia.org/wiki/Drag_coefficient

As you see, adding what *looks* like something of a fairing to the trailing edge to does nessarily mean it will work as one and may make things worse, and poor leading edge makes tail fairing ineffective - which is the greatest problem on tailfairings on recumbents.
Human body makes for a very poor leading edge, 'splashing' the air to the side, creating large-scale vorticity that make pressure recovery hardly possible even with very good-looking tailfairng.
This picture is particularly telling:

The prism vs the bullet vs the sphere in particular
Image

Also, here is a great artcle with very interesting results:
http://www.recumbents.com/wisil/misc/no ... efault.htm

All in all, you can hardly expect decent results from front fairing because it cannot provide pressure recovery...
You cannot expect good results from tail fairing because a human body is a terrible leading edge...
You can only expect good results by a combination of front and tail fairings by merging them into a complete whole - that would be a FULL fairing, with front fairing providing smooth airflow to the tail fairing which would do it's thing and greatly reduce air drag - but it creates cooling, ingree-egress issues and crosswind sensitive.

A combination of closely fitting front fairing and rear fairing, even if separated by a gap should work provided the gap is *small*.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by BalorNG » Jan 18 2022 6:37am

I think I've mentioned that somewhere already, but by apping the dork factor to eleven you can use wearable farings to fix the 'poor leading edge' and get rid of at least ingress-egress issues while considerably boosting efficiency of a tail faring...

Image

Still does not hold a candle to a fully faired design of course, and you must have a rather thick skin :)

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by SafeDiscDancing » Jan 18 2022 11:17am

BalorNG wrote:
Jan 18 2022 2:25am
What you elaborate further?
Sure.

We have * Braking (upright), * Counter Steer (rotation), * Dive (unweighted), * Lean (fully weighted).

The professional racer sees these as independent actions and does not mix them up because each needs to be carefully kept separate.

We use terms like "Dive into the Corner".

Actually part of the thrill of being a skilled rider is this commitment to the turn once you get into your dive.

Image

The rider in the background is in his "Lean" and the rider in front is in his "Dive".

You hear this talked about endlessly in the racing dialog as someone overdoes it into a turn and body checks another causing both to go down and the offending rider typically says:

"I'm sorry but I had already committed to the turn and could do nothing at that point."

Over the years of watching MotoGP racing I figure this dialog has been repeated at least a hundred times if not a thousand.

Now my "guess" is you have never drifted a motorcycle or bicycle but preferred a "stable" steady ride.

Is this accurate? You have zero racing knowledge?

As for me I have raced BMX, Mountain Bikes, Motocross (trophies in each) and street Raced motorcycles for years as well as hung out at the race tracks and even worked as a mechanic to help out another racer. (Laguna Seca and Sears Point)

Do you grasp this difference?

Basically I "know" from decades of experience how to do all the things I talk about.

And CowardlyDuck is correct that the thread is about aerodynamics but the slow handling (stable) nature of the lower center of mass designs places limits to the ability of them as "sport" vehicles like MotoGP bikes which are more "sport" than aerodynamic.

In MotoGP the power and speed came first and worries about aerodynamics second.

These days the motors on those bikes are up around 300 horsepower... not sure of the exact number.
Last edited by SafeDiscDancing on Jan 18 2022 11:47am, edited 9 times in total.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by Warren » Jan 18 2022 11:23am

Royce Creasy is the man to ask. He is currently building his first EV version.

https://bikeweb.com/node/241

https://vimeo.com/661593045

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Chalo   100 GW

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by Chalo » Jan 18 2022 11:44am

SafeDiscDancing wrote:
Jan 18 2022 11:17am
but the slow handling (stable) nature of the lower center of mass designs places limits to the ability of them as "sport" vehicles
Low isn't stable. Low is tippy because the roll rate is too fast.
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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by SafeDiscDancing » Jan 18 2022 11:52am

Chalo wrote:
Jan 18 2022 11:44am
Low isn't stable. Low is tippy because the roll rate is too fast.
It depends on speed.

If the low center of mass bike is going 200 mph it's not going to be easy to get it to change direction.

But at slow speed any steering will cause wobbles... "Wheebles Wobble But Don't Fall Down".

Image

The slow speed wobbling might be annoying but probably people could adapt to it.

-------------------------

MadRhino also pointed out that if the bike had a low center of mass and the rider stood "over" the top of it you now have a Wheeble underneath being manipulated by a lever which is the rider far above.

That allows the trials rider to use exaggerated body english to initiate action.

Recumbents? No. They place the rider down low. Seems that the ones with the rider up higher should be better overall as far as being closer to a regular bike.
Last edited by SafeDiscDancing on Jan 18 2022 12:14pm, edited 1 time in total.

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Re: Do you use an fairing or partial fairing on your ebike, emoped or BSM?

Post by Chalo » Jan 18 2022 12:07pm

SafeDiscDancing wrote:
Jan 18 2022 11:52am
Chalo wrote:
Jan 18 2022 11:44am
Low isn't stable. Low is tippy because the roll rate is too fast.
It depends on speed.

If the low center of mass bike is going 200 mph it's not going to be easy to get it to change direction.

But at slow speed any steering will cause wobbles... "Wheebles Wobble But Don't Fall Down".
True for Weebles, but low bikes fall down real good.



Last edited by Chalo on Jan 18 2022 1:01pm, edited 1 time in total.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

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