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

[ebike4healthandfitness]

Would be interesting to see how well this one does on a roll down (i.e. coast down) test?

I'll bet it does pretty good. It appears to be in the same class as a LWB recumbent.

 

[Chalo]

Would be interesting to see how well this one does on a roll down (i.e. coast down) test?

I'll bet it does pretty good. It appears to be in the same class as a LWB recumbent.

No.

First of all, sit-up-straight recumbents don't have less drag than regular bikes. They might do a little better than sit-up-straight Dutch bikes or other extreme examples, but that's not saying much.

Second, those tires add both aero drag and an abnormal amount of rolling resistance.

That bike might be pretty fun to ride in spite of its awkward weight distribution and fat-tire self steering, but it will definitely be slow.

We've spent over 150 years now homing in on a bike design that offers the best performance for a reasonable average amount of pedal effort, comfort, and functionality. It's just a regular bike. When you change it, it's overwhelmingly likely you're trying something that's been tried many times already over the course of generations, and rejected because it makes the bike worse more than it makes it better.

 

[ebike4healthandfitness]

Would be interesting to see how well this one does on a roll down (i.e. coast down) test?

I'll bet it does pretty good. It appears to be in the same class as a LWB recumbent.

No.

First of all, sit-up-straight recumbents don't have less drag than regular bikes. They might do a little better than sit-up-straight Dutch bikes or other extreme examples, but that's not saying much.

The riding position looks identical to what is pictured as LWB recumbent in the calculator below:

http://www.kreuzotter.de/english/espeed.htm

There are only two main differences:

1. Handlebar position. On this cruiser the handlebars are above the seat. On the LWB recumbent pictured in the calculator they are under the seat. Which handlebar set-up produces more drag? I think from the human body position standpoint the above seat steering would be less, but from a bicycle frame standpoint the above seat steering is definitely worse.

2. Wheels/tires: On the cruiser the front tire is much larger diameter (29+" vs. 20") while also being wider (4" vs. est. 2"). On the cruiser the rear tire is larger in diameter (29+" vs. 26") while also being wider (4" vs. est 2"). The wider and taller tires will increase aerodynamic drag over smaller diameter thinner tires.

So as pictured, the LWB recumbent beats the cruiser as far as aerodynamic drag goes. However, that same part of the cruiser (the above seat steering) that contributes to higher drag can be used to easily mount a front fairing while on LWB recumbent mounting a front fairing is much more difficult. As far as tires go there is nothing about the cruiser that forces 4" wide to be used. The cruiser could easily use 2" wide tires or thinner assuming the proper width rim was used.

Overall, I think the cruiser would have pretty good aerodynamics assuming 2" wide tires....certainly better than a Roadster (classic Dutch upright bike) or a unsuspended mtn bike.

Some power figures below from the kreuzotter.de calculator for various bikes at 28 mph (default values kept, but rider changed to 70" tall with weight at 200 lbs (i.e. average Amery male height and weight)):

Roadster (classic upright Dutch bike): 1025 watts
Mountain, unsuspended: 795 watts
Road, hands on tops: 685 watts
LWB recumbent, under seat steering: 662 watts
SWB recumbent, under seat steering, commuter: 526 watts
Road, hands on drops: 486 watts
Triathlon: 413 watts
SWB recumbent, above seat steering, race: 363 watts
Low racer: 287 watts

 

[donn]

It isn't in the same class as an LWB recumbent, at all.

Whatever the exact angle of recumbency, a recumbent provides a seat back to lay back on. That's going to affect posture at least a little (as well as supporting pedaling leg force that's no longer offset by body weight as it would be on an upright bicycle.) I don't think you'll find any image of a "chopper" style bicycle with someone riding it in anything like an aerodynamic position - more the opposite, they'll be forming the closest human equivalent of a wind sock.

Don't be put off by Chalo, who seems to have been traumatized by some early experience with a recumbent. Like your kreuzotter table, ebikes.ca's simulator ecognizes that recumbents and "semi-recumbents" have some aerodynamic advantage over upright bicycles. For example, at 20 mph, with 100W human input, their semi-recumbent takes about 1 Wh/mile off the battery consumption of a road full tuck. That isn't a whole lot - but then a full tuck road bike is someone going to a lot of trouble for the sake of aerodynamics.

I'd be interested to know what they were looking at for a semi-recumbent, but I have been assuming it's something like the old Infinity that traumatized Chalo, pictured on page 4 of this thread. "Crank forward" bicycles aren't recumbents, and they aren't semi-recumbents.

 

[BalorNG]

It isn't in the same class as an LWB recumbent, at all.

Whatever the exact angle of recumbency, a recumbent provides a seat back to lay back on. That's going to affect posture at least a little (as well as supporting pedaling leg force that's no longer offset by body weight as it would be on an upright bicycle.) I don't think you'll find any image of a "chopper" style bicycle with someone riding it in anything like an aerodynamic position - more the opposite, they'll be forming the closest human equivalent of a wind sock.

Don't be put off by Chalo, who seems to have been traumatized by some early experience with a recumbent. Like your kreuzotter table, ebikes.ca's simulator ecognizes that recumbents and "semi-recumbents" have some aerodynamic advantage over upright bicycles. For example, at 20 mph, with 100W human input, their semi-recumbent takes about 1 Wh/mile off the battery consumption of a road full tuck. That isn't a whole lot - but then a full tuck road bike is someone going to a lot of trouble for the sake of aerodynamics.

I'd be interested to know what they were looking at for a semi-recumbent, but I have been assuming it's something like the old Infinity that traumatized Chalo, pictured on page 4 of this thread. "Crank forward" bicycles aren't recumbents, and they aren't semi-recumbents.

Well, while I've been intentionally 'traumatizing' myself with recumbents for the last 5 years, and see their shortcomings as a technical challenge to overcome, not a just a 'turnoff', I agree with Chalo that they most certainly exist, but as he himself would (grudginly, ehehe) agree, there is no 'one perfect' design, because some design constrains are mutually exclusive and you 'cannot have it all' (and it is woefully easy to have neither).

The 'sit up and beg' formfactor, while allowing significant 'body english', brings NEITHER speed NOR comfort. The 'speed' aspect is rather obvious - upright torso cycling is the least aero position possible... and the term 'recumbutt' was not invented by 'recumbent haters', unfortunately - this is what you get when your entire body weight is concentrated on your buttocks - you butt gets tired even if you sit on an office chair all day w/o reclining or walking about, and even wide 'bicycle' seat is just woefully inadequate for such a position unless you are skinny perhaps - getting a right seat for such a position is not an easy task, I dareday harder than for an 'upright bike'.

A nearly supine position has great aero AND comfort, but takes away 'body english input' that we take for granted and what the 'lowering of bike CG' is actually all about - getting back to 'control' aspect lowering the 'bike' CG is all about (highly scientific term incoming!) *flickability*. Only recumbent with a tiny shred of 'flickability' I've ridden is the Rinzler, where you can truly 'move the bike around from under you', hence affecting balancing without actual steering input, that takes traction you do not always have - that takes a considerably upright position AND underseat bars.

 

[ebike4healthandfitness]

I don't think you'll find any image of a "chopper" style bicycle with someone riding it in anything like an aerodynamic position - more the opposite, they'll be forming the closest human equivalent of a wind sock.

Fairly certain the frontal area would still be lower than a mtn bike or Roadster (i.e. classical Dutch upright bike) and maybe even the road bike.

The wind sock is something to think about. Apparently a partial is good for fixing that though.

 

[BalorNG]

I don't think you'll find any image of a "chopper" style bicycle with someone riding it in anything like an aerodynamic position - more the opposite, they'll be forming the closest human equivalent of a wind sock.

Fairly certain the frontal area would still be lower than a mtn bike or Roadster (i.e. classical Dutch upright bike) and maybe even the road bike.

The wind sock is something to think about. Apparently a partial is good for fixing that though.

Yea. A partial fairing is good for fixing flaws on a position that is actually worse than a flat plate
Simply reclining more brings more speed AND comfort, and is adequate for cruizing on well-paved roads.

Aerobars on an upright bike, especially the 'praying mantis' position is even better though, but neck comfort takes a huge hit. though less extreme aerobar positions can be surprizingly comfortable, and combining them with a partial fairing is where you can, indeed, have considerable benefits, especially with wearable fairings (again, if you don't mind the 'dork factor').

 

[BalorNG]

I've been riding my LWB on a trainer and monitoring my 'body envelope'.

All in all, I *think* that a narrow-ish USS bars, a front fairing that flips up and forward, all like on electrom - but with a true ogive shape and *closed* sides, so it sits *VERY* close to your body when 'deployed' , a *proper* tailbox (large and with angle of convergeance to allow pressure recovery) and a set of wearable plate fairings on your arms so air can be channelled from front fairing to rear fairing w/o irrecoverable vorticity might just work - that in allow fairing peformance which is a significant portion of a true full composite fairing, but without ingrees-egress issues, less wind steer and much more control and going low enough, but not too low would allow a truly wide seat that is comfortable on long rides (close to an office seat than to a bicycle seat).

 

[donn]

My favorite seat is less office chair and more lawn chair - the seat on my Ryan Vanguard, a sling between side rails and a front pivot. I don't recall any discomfort from it ever, where the office chair style on my Burley is not awful but a little harder to get along with. I don't expect it would work well for a more "open" position, i.e. less acute angle between back and legs.

Would the USS bars you have in mind here be turned as everyone does these days, so that your thumb point towards the end of the bars? or classic straight bars that really are under the seat?

 

[BalorNG]

My favorite seat is less office chair and more lawn chair - the seat on my Ryan Vanguard, a sling between side rails and a front pivot. I don't recall any discomfort from it ever, where the office chair style on my Burley is not awful but a little harder to get along with. I don't expect it would work well for a more "open" position, i.e. less acute angle between back and legs.

Would the USS bars you have in mind here be turned as everyone does these days, so that your thumb point towards the end of the bars? or classic straight bars that really are under the seat?

Like on Rinzler... or, maybe, like on electrom as well, it also allows considerable direct roll input without steering input (I think it is still better on Rinzler)

 

[spinningmagnets]

Chalo has provided a great deal of useful information, and yet...I still ride what I like.

For me, its not that an ultralight road bike is more aero than my ebike, it's that my fat-tire upright beach cruiser is more aero and lighter than my car.

Let not the perfect be the enemy of the good.

 

[BalorNG]

Chalo has provided a great deal of useful information, and yet...I still ride what I like.

For me, its not that an ultralight road bike is more aero than my ebike, it's that my fat-tire upright beach cruiser is more aero and lighter than my car.

Let not the perfect be the enemy of the good.

When it comes to 'enemy of the good', I walk commute
But when it comes to 1000+ km travels, neither fat tire beach cruiser, nor, ehehe, walking, will not do it.

 

[SafeDiscDancing]

And let's never forget the feeling as a kid on your BMX bike riding a wheelie down the street or doing a bunny hop or going off a jump.

Never forget that piece of plywood you propped up with a cement block so you could jump ten feet off it.

Try to remember your first time at a half pipe successfully doing a 180 and feeling like it was totally fluid and natural.

We need to remember the fun on these bikes.

And when it comes to aerodynamics if the fun is taken out too much and it becomes something that can only hold a straight line then you have lost something.

This is why I think these mixed solutions where the ebikes still handle well with good traction and good brakes is important.

Fun really matters. I know these days our sense of free play is under attack, but even at 60 years old I still experience bicycle riding as though I was that 14 year old on a BMX bike.

 

[tigcross]

There is a lot of back and forth going on here, and as someone who has been riding a semi-faired electric recumbent for over ten years I have some specific knowledge.

• A fairing is about much more than just aerodynamics, it can provide weather protection, crash protection, and offers a handy place to mount things like mirrors and ebike consoles.

• We're talking about e-bikes, so obsessing over things like tire rolling resistance at the expense of road-worthiness is just silly. One of the best things about an electric recumbent is that with the extra power one can focus on making a bike that works well in real-world situations and has fewer compromises because of weight concerns.

• A LWB recumbent offers some real advantages when it comes to battery location, there is tons of space below the rider for batteries and it is an ideal location when it comes to weight distribution.

• It is not true that recumbents cannot have upright bike handling, they just have to be designed for it. My bike is a SWB recumbent with USS and a seat back. If I need fast handling I just lift my back away from the backrest and I am able to employ all kinds of counter-steer and counter-lean techniques. The fact that my steering is USS instead of a tiller does help with this as I can exert sideforce on the bars without turning the bike. .

• While a full fairing would be nice, it's not ideal on a two-wheel bike as it presents too much surface area in cross-winds. However, a set of removable side panels, probably of cloth, would be great for non-windy situations.

I'm in agreement with spinningmagnets "Let not the perfect be the enemy of the good"

 

[BalorNG]

• It is not true that recumbents cannot have upright bike handling, they just have to be designed for it. My bike is a SWB recumbent with USS and a seat back. If I need fast handling I just lift my back away from the backrest and I am able to employ all kinds of counter-steer and counter-lean techniques. The fact that my steering is USS instead of a tiller does help with this as I can exert sideforce on the bars without turning the bike. .

Yup! That's exactly what I mean - few recumbents have that. Rinzler USS is also zero tiller.

 

[Chalo]

Yay! Special techniques to maybe catch up to the manners of a totally normal bike! I guess everybody was wrong for the last century plus.

 

[BalorNG]

And let's never forget the feeling as a kid on your BMX bike riding a wheelie down the street or doing a bunny hop or going off a jump.

Never forget that piece of plywood you propped up with a cement block so you could jump ten feet off it.

Try to remember your first time at a half pipe successfully doing a 180 and feeling like it was totally fluid and natural.

We need to remember the fun on these bikes.

And when it comes to aerodynamics if the fun is taken out too much and it becomes something that can only hold a straight line then you have lost something.

This is why I think these mixed solutions where the ebikes still handle well with good traction and good brakes is important.

Fun really matters. I know these days our sense of free play is under attack, but even at 60 years old I still experience bicycle riding as though I was that 14 year old on a BMX bike.

Never did any of the sort, so I have nothing to remember and nothing to miss

 

[BalorNG]

Yay! Special techniques to maybe catch up to the manners of a totally normal bike! I guess everybody was wrong for the last century plus.

Yup. In my case I never pretended my bents to be anything else than a 'special needs bicycles', for instance - because my needs ARE special, but I still want level of control inherent in 'upright' formfactor.

 

[donn]

Yay! Special techniques to maybe catch up to the manners of a totally normal bike! I guess everybody was wrong for the last century plus.

I know my ass felt wrong, and my neck, and to some extent my hands.

 

[calab]

Well there are different ass feelings when I was sitting on the couch for days my bum got sore because I was sitting on my wallet but that feeling is the same feeling I used to get when I drove for hours, the sore bum kept me up at night and I put up with it for 2 nights until I took a tylonol, it was just annoyingly sore. When I ride ebikes I like big cushy seats with some seat suspension (elastromer, springs) but my bum hardly gets sore and its not like I pedal a lot. My bum cant deal with normal non cushiony seat cushion. If I am riding for long hours, my bum can get sore on occasion once or twice a year so I like to stand up on the pedals to stretch it out.

When it comes to the next my neck only gets sore when sleeping because I sleep in the wrong position, but when I ride ebike my head is looking around all the time when riding on the roads and sidewalks.

My hand gets sore often when riding ebike I call it throttle hand using the thumb throttle on a throttle only ebike, no pas.

I am not about to not be seen by riding a low recumbent close to the ground, and using a handle bar fairing is never in my books. I would say the only close thing to that are handle bar covers to only help against wind chill.

Yay! Special techniques to maybe catch up to the manners of a totally normal bike! I guess everybody was wrong for the last century plus.

I know my ass felt wrong, and my neck, and to some extent my hands.

 

[tomjasz]

[We are talking about a Sur Ron so they already weigh a good amount and are not pedal bikes so no worries about knee clearance.

Great ride for short riders. High knee position for anyone over 5’8”. IMO

 

[SafeDiscDancing]

Never did any of the sort, so I have nothing to remember and nothing to miss

Oh, I get it then.

You were that "dorky kid" that maybe your mother was afraid you might scratch your knee so she required you to stay home while the other kids were playing rough and tumble games.

I was the middle of THREE SONS and let me tell you we were always playing rough and tumble games and our neighborhood had kids our age so we could get full football games together where we literally beat each other sore all the time. And let me add that I routinely went up against bigger guys and I simply was willing to hit harder and take more pain. I was never bullied but also never bullied others.

My neighborhood was then "incomplete" and some land was still vacant so I built my own BMX track on it and was able to ride every day.

So it gave me this deep appreciation for real sport.

To really attain high skill levels on any cycle you NEED dirt track experience.

Look at MotoGP as an example... many will train in Motocross when in the off season.

Knowing how to drift the tires while being confident and in control of it is what defines real talent.

And I know... VERY FEW.... people ever in their lifetimes experience this type of peak mastery.

So you confirm what seems obvious... the "dorks" love the recumbents.

 

[BalorNG]

You were that "dorky kid" that maybe your mother was afraid you might scratch your knee

Nope, I just was never interested.

So you confirm what seems obvious... the "dorks" love the recumbents.

Yup. No denying that.

I still don't mind risking my life piloting a strange contraption with dubious control characterises while enduring extremes of exhaustion in what amounts to 24 hour races (just without the sense of urgency)... provided I do that in comfort ..
All the while you seem to not mind risking lives of *others* it seems.

I'd much prefer being the dork, thank you.

 

[SafeDiscDancing]

All the while you seem to not mind risking lives of *others* it seems.

I'd much prefer being the dork, thank you.

The physics only cares about mass and momentum.

So if a self described "dork" crashes because the vehicle lacks control by design is that different than someone breaking Natural Law by poor riding ability?

In other words if you HAVE TALENT you should be more capable of not causing harm.

And let's be clear on that too... one should avoid "causing harm to self and others".

Self harm is another violation of Natural Law. Pain is okay because it is an illusion, but harm is material.

If you banned pain the entire Tour De France would need to be shut down because it is a long "Painfest".

I have ridden at minimum 10,000 miles on my Class 3 ebike and even drifted the tires on it and had no crashes.

Just because you wobble around and "feel" you are Virtue Signaling in an unusual way does not mean the laws of physics or skill levels are in your favor.

 

[Warren]

I guess everybody was wrong for the last century plus.

They were wrong about cars, and climate change, so why are you surprised they were wrong about bikes. lol