Julian Edgar, 50, has been writing about car modification and automotive technology for nearly 25 years. He has owned cars with two, three, four, five, six and eight cylinders; single turbo, twin turbo, supercharged, diesel and hybrid electric drivelines. He lists his transport interests as turbocharging, aerodynamics, suspension design and human-powered vehicles.
Time for a Paradigm Shift in Pedal Power
As I write this, I am on holidays – something that also won’t be the case by the time you actually read this!
In addition to doing four AutoSpeed stories, I’ve been spending the time cudgelling my brains over my upcoming Human Powered Vehicle project – a front-wheel drive, delta (two rear wheels, one front), recumbent, leaning trike.
I’ve looked through the articles I’ve previously done in AutoSpeed on recumbent pedal trikes (including the tadpole trike pictured above), and have been furiously scanning the web.
Recumbent bikes (where the rider sits back in a reclined seat, the pedals in front of him or her) make up only a tiny minority of bikes worldwide.
Recumbent trikes make up a small minority of that tiny minority – and recumbent, delta, leaning trike designs can be counted on the fingers. Of two hands.
Thus web searches have tended to return to the same sources, taking any one of a number of routes to get there.
As a result of the small number of web pages dealing with this topic, I have had a chance to re-read my posts to an online recumbent bikes/trikes forum, one that has a specific area for homebuilders. Before I was banned, I was almost pleading with those who had developed recumbent trikes to do some testing and measurement of their machines’ performance, so that the tiny community of scattered builders around the world could actually compare designs and see which approaches were best.
Seems an obvious request, but it was met with refusal.
And now, when I am designing just such an unusual machine, I feel that frustration all over again – if anyone had bothered to get off their arse and actually do some testing to support their claims, I would now be benefiting. Just as anyone else building such a machine would equally benefit.
Anyone can build anything and make whatever claims they like about it, but without careful testing, their statements are largely meaningless. And I don’t even mind if they do the testing themselves – at least there would be some data to go on…
Thinking through the new HPV design, I’ve come to a few conclusions. They’re new to me, although of course not necessarily to lots of other people! So perhaps I’ll put them to you simply as points:
– Traditional diamond frame bikes proliferate in racing because in most events, better, faster bike designs are banned.
– As a result of seeing only this type of bike, most people assume that it is the best type of bike.
– Sitting on a tiny seat – one about as big as your hand – is not something anyone would normally do voluntarily, so why do it on a pedal machine?
– People way over-estimate the importance of low weight and speed in a pedal machines. Unless you’re racing, surely better comfort and easier riding are more important aims?
– When riding in a comfort completely foreign to 99.999 per cent of bike owners, the required physical effort becomes easy. It’s often the case that you get tired on a normal bike because developing the physical effort is uncomfortable, not because of the physical effort per se.
– A recumbent, properly suspended pedal machine reduces the shock of bumps by around 80 per cent, making effectively every surface act like the smoothest concrete you can ride along on a traditional diamond frame bike. And of course the seat is as big as an armchair…
– People are hungry for sustainable, alternative and comfortable human-powered transport with low running costs. It’s technically achievable right now, to a degree that would simply flabbergast most people.
Next time you think of pedal power, stop thinking about upright, diamond-framed bikes. They’re inferior in nearly all applications to the machines now able to be built.
Disclaimer: my wife’s business, SpeedPedal, sells recumbent trikes.
on February 3rd, 2009 at 12:25 am
The traditional diamond-framed bike has survived for so long because it is a light and structurally-efficient design. I think riding a much heavier recumbent trike would prove very tiring in the hilly countryside of the UK where I cycle. One of the main disadvantages of recumbent bikes is that it is not possible to use your body weight to assist in climbing hills. However, I agree that better seat comfort and a riding position that does not involve craning your neck to see where you are going would help make cycling more attractive to newcomers. What about a fairing to improve aerodynamics and keep the weather off for those of us who don’t live in warm places like Australia!
on February 3rd, 2009 at 7:21 am
what is the bike forum’s name? Just keen to see..
Julian, The next few years will be really interesting. When petrol prices return to their altitude and as battery tech improves pedal and motor assit will get more and more user friendly. I can see the day when your and my kids will ride to work on their segue inspired vehicle and hopefully the roads will be far less clogged for it.
Just need to convince the drones that a big 6 is not needed for the average journey.
on February 3rd, 2009 at 7:25 am
It is a misconception that it takes more power – or is more tiring – to climb hills on a heavier machine. It just takes longer at a slower rate. Therefore, if speed does not matter…
In a way you do not use your body weight on the pedals to assist in climbing hills (or any pedalling for that matter). Instead, you lift your body weight against gravity, thus the max pedal push you can get is your body weight. On a recumbent, you can actually push harder than your body weight (if you wish to do so). However, it is better to use lots of gears and ‘windmill’.
But I certainly agree that a diamond framed bike is structurally a brilliant deisgn.
on February 3rd, 2009 at 7:26 am
http://www.bentrideronline.com
on February 3rd, 2009 at 10:41 am
While I reckon HPV’s would be great in some kind of post apocalyptic, no oil era, I think they have a number of very significant shortfalls for a typical city commute:
1/ you can’t bunnyhop gutters (and low ground clearance will generally preclude riding off them)
2/ You’re below windscreen / bonnet height and out of view (also many cyclists who get hit slide up onto the windscreen)
3/ you can’t weave between narrow gaps – not just between cars, but other obstacles too such as posts on bikepaths, grates etc.
As far as pedalling comfort goes, while the seated position is nice, the upright position allows a number of different riding positions and therefore you aren’t straining just one set of muscles (you can notice the long term recumbent riders have different shape quads compared to say a jogger)
But I definitely agree that the achievable performance far exceeds the expectations of many.
on February 3rd, 2009 at 10:57 am
BG:
1) Why should you be jumping off gutters?
2) That depends only on the height of the recumbent
3) That depends only on if it is a trike not bike (and then depends on the track of the trike)
on February 3rd, 2009 at 12:23 pm
1/ I’ve found over the years that city bicycle commuting routes are a real jumble and being able to negotiate obstacles makes a real difference. In the past I have compared times between riding a mountain bike, where I can ride off gutters, across parks and embankments etc., to riding a ‘road racing’ bike over the same trip(s) – for eg. 57 mins by mountain bike, 55 mins road bike – manouvreability makes a big difference.
2/ Yes that’s true, but a high recumbent will more likely to be a tall, two wheel recumbent – and these are generally slow reacting and don’t brake as well which don’t help in traffic. Maybe the taller tricycles are high enough to see better (for eg. the one you ride)
3/ That does only apply to a trike – but many bikeways really aren’t very wide if they’re divided with a post. Whether this makes a difference would probably depend on the particular route. For example, our lord mayor in Brisbane is fascinated by road works, which can narrow major bike routes to 1m wide each way:
http://www.halestreetlink.com.au/home/news.asp?nid=53
– this bikeway carries several thousand cyclists per day. I’m sure trikes won’t have any real trouble getting through but they’re stretching their brains just to accomodate 2 wheel cycles.
on February 3rd, 2009 at 12:34 pm
To continue BG’s points:
1) I never jump off gutters, not with a lightweight aluminium and carbon fibre road bike. I do however at one point in my commute stop, and on one foot step my bike off a gutter to transition from a bike path that veers away from my route onto the road.
2) All the ‘bents that autospeed has featured are much lower than a normal bike. BUT I’m not sure you are less visible. The greenspeed site goes into this in detail.
3) On my daily commute I squeeze through obstacles that are difficult on my upright road bike. I can’t see any ‘bent managing them without having to take a longer route. Or dismounting, clean and jerking the bike overhead, and walking through.
4) You mention quad growth like it’s a bad thing.
Also, riding a heavier bike up a hill in lower gear does not need more power, but it does need more energy. And, clearly, more time. I have two regular journeys that I can optionally do by bike. One takes 45 minutes, and I ride it, the other takes 90 minutes, and I very rarely bother.
Taking a step back, and it sounds like Julian is trying to use words to convince people of something that they just have to try. Maybe you really just need a recumbent rental service. Once people try it, they’ll see what you’re talking about. (I assume, I haven’t ridden one.)
on February 3rd, 2009 at 12:43 pm
“…..sounds like Julian is trying to use words to convince people of something…” is just about my job description!
I guess also I am writing this in the context of building a new machine, one that will have excellent visbility, excellent comfort, will brake extremely well, and will have a track only 10cm wider than the handlebars of a typical bike. But, in bike terms, it will be heavy (and very expensive, too).
on February 3rd, 2009 at 12:54 pm
4) You mention quad growth like it’s a bad thing.
I’m sorry I just don’t find recumbent riders as hot and sexy as most cyclists 😉
on February 3rd, 2009 at 12:56 pm
Well it is a very high standard to beat. 😉
on February 3rd, 2009 at 2:26 pm
I can ride a mountain bike or road bike for hours and hours, endless kilometers, and barely get sore. I rode 30km on a single speed mountain bike in 40 degree heat, it was easy as.
But then again, I spend 99.9% of my bike riding time (which is at least 30 hours a week) on a 20 inch BMX. I ride skateparks etc and use it to commute to and from work. Even though it’s not quite as fast as a road or mountain bike, it is far more nimble, very handy for city situations.
I don’t run brakes on my bike, can still stop on a dime, turn very quickly to avoid cars that aren’t paying attention, and hop up anything from a curb to a 1m wall.
But back to the point. Riding a bmx is uncomfortable. Riding a road/mountain bike isn’t. For city riding, I can’t see the agility of even a big bicycle being outweighed by comfort benefits of a recumbent.
on February 3rd, 2009 at 2:28 pm
I forgot to add that I would be scared sh-tless riding a recumbent through the city and surrounding suburbs, at least any of the recumbents I’ve ever seen.
on February 3rd, 2009 at 3:16 pm
I must admit, one of my biggest fears about recumbent bikes is the manoeuvrability.
On my mountain bike I feel far more agile than on my racer. I don’t’ have to worry about curbs, drains or even split and cracked footpaths as I do on a racer and if I have to duck off the road in emergencies, I can do that on my MTB.
Furthermore the brakes are awesome and the visibility is great (and the upright position good on the neck muscles).
I’ve never ridden a recumbent, but I’d be concerned about riding on the road. I don’t think it is something you can make a quick manoeuvre on.
I don’t know, perhaps if I tried one, I’d think differently but a two-wheeled upright always gives you more control to chuck the bike around.
on February 3rd, 2009 at 3:54 pm
What do people mean, precisely, by “manoeuvrability”? Actual examples?
on February 3rd, 2009 at 4:03 pm
Some examples of legitimate, legal situations:
1. Riding into an intersection, there are no cars travelling in my direction, but there are cars travelling the opposite way. There is a car waiting turning right that doesn’t see me, I am past the point of no return and have to turn and skid quickly. I avoid a collision.
2. Riding down a street past parked cars. It is a busy road so I have to ride quite close to them. A motorist exits their car and opens the door 2 m in front of me. Not enough time to break, so I swerve out of the way quickly, avoiding the door and impending collision.
3. Above situation, except inattentive pedestrian crossing the road where no pedestrian crossing exists. Dodge and swerve, avoid crash.
4. Bus is coming up behind me, and cuts in front, possibly due to not seeing me or possibly due to driver carelessness. I have to bunnyhop up the gutter to avoid being ‘sandwhiched’ between the bus and the gutter.
And a not so legal situation:
Traffic is banked up for miles, and cars are lined just that little bit too close to the curb to comfortably ride between the curb and cars. I bunnyhop up the gutter and ride along easily at a moderate pace, watching out for unwitting pedestrians.
This is stuff that happens every day, and this is only riding in Adelaide CBD… I’ve ridden around Sydney and Melbourne, they are far more difficult to navigate on a bike, as well as being far more hectic and jam packed.
Sorry Julian, I just can’t see people riding around built up and city areas on a recumbent, at least with the ease that we do on a bike. Have you ever ridden a recumbent through a CBD during peak hour?
on February 3rd, 2009 at 4:31 pm
Hey in QLD it’s legal to ride on the footpaths..
I think swerving and braking manoeuvres can be competently done on a trike, but less so on a two wheeled ‘bent. Weaving on and off kerbs and footpaths, stairwells and jumping embankments might be a lot harder on a recumbent!
A trike does have an inherent cornering / weaving advantage: to turn left, you just turn left. On all bicycles, you need to make a very small right turn first, to allow you to lean your weight left into the corner – which all takes up valuable distance. That’s why steep steering angles and small wheels are faster reacting.
on February 3rd, 2009 at 4:47 pm
Examples from my last week:
1. Riding along a bike/foot path by the side of the road, the road is jammed with cars waiting to enter a round about. The garbage collection has left a couple of the wheelybins lying on their sides, across the path. I have to weave through the zigzag space available.
2.Riding through the company carpark to work, a delivery van suddenly backs out, needing a sudden change of direction. I suppose that I could have just braked in this case.
3.My wife finishes a meeting early and picks me up from work. I just take the wheels off the bike and pop it in the boot of the car. A recumbent would either need to be a collapsible design, or we would need a bigger car. Or I suppose we could drive around all the time with a bike rack on, in case we ever need to carry the bike.
Please note, I am not opposed to the recumbent idea at all, I can see it has many advantages. I can just also see the disadvantages, which I sum up as: Bigger, heavier, lower, much more expensive. I’ll concede that heavier may not actually matter, but I’ll need a test drive to be convinced.
Or I take the buckled mountain bike under my house and make myself one…. a single speed fixed gear bamboo frame ‘bent.
on February 3rd, 2009 at 5:18 pm
I think in the duck and weave cases, a recumbent trike can easily be shown to be superior to a conventional bike in manoeuvrability. (But maybe not to a BMX with James W riding it – he appears to be in a different class).
The combination of ducking, weaving, twisting to fit the handlebars through a gap nominally smaller than their width, jumping kerbs, etc is something else.
Yes, I have ridden my recumbent trike in heavy, stop/start urban traffic. I just take up a whole lane and go at the pace of the cars.
I might add that the recumbent bike I briefly owned (see http://blog.autospeed.com/2008/03/25/bikes-bikes/) was quite awful, and I would never, ever have ridden that in traffic.
But I certainly take the point about portability and footpaths, etc – I take the Brompton in those cases (again see http://blog.autospeed.com/2008/03/25/bikes-bikes/).
I have a blog coming up on it, but the machine I am now building will (hopefully!) have the following specs:
It’s a touring, leaning delta trike with lockable tilt
…so it acts as virtual bicycle at speed but still has the stability of a three wheel machine at low speeds (eg climbing hills) and when stopped.
front wheel drive
… the front wheel is also steered, so the drive chain twists to accommodate this movement.
recumbent seat
…the most comfortable pedal machine seat ever? Must be close I think.
6 inches (150mm) suspension travel
… quite massive, and allowing a very soft spring rate to be used while still maintaining bump travel.
air springs
…rolling lip Firestone airbags, similar in some ways to trucks and buses but tiny.
height-adjustable suspension
…just change the airbag pressure with a normal bike pump.
front damper
… the rear suspension is damped by track change.
anti-dive front suspension
…only about 25 per cent anti-dive; too high an anti-dive leads to suspension harshness.
anti-squat rear suspension
..the machine will be twice as stiff in squat as it is for a single rear wheel bump.
81 gears
…and very low gearing at that. This is a touring machine that will climb any hill while still carrying a full load, and even pulling a child trailer.
active levelling under pedalling forces
…the chain pull causes the extension of the front suspension to be counter-acted.
in-built provision for two touring panniers (40 litres) and a rucksack (65 litres)
…that’s a massive amount of spray-proof volume, and the rucksack can be removed for walking tours.
60 litre volume under seat for tent, sleeping rolls, etc
…that’s another massive amount of carrying capacity. And it’s all within the wheelbase – utterly different from most touring pedal machines.
front hydraulic disc, rear drum brakes
…the big discs will haul off speed fast – I calculate up to 0.8g decel will be possible when fully loaded. The rear drum brakes will help provide braking stability and with three good braking systems, this machine should always stop.
folds / disassembles into 100 x 75 x 40cm package
…that’s big for a folding bike, but very small for a touring machine of this capability. A full fold / disassembly should take less than 10 minutes.
seat removes and becomes self-supporting portable seat
…so there’s a seat available whenever you stop!
on February 3rd, 2009 at 6:52 pm
can we stick to cars, and all aspects of it?
cheers
on February 3rd, 2009 at 6:56 pm
No.
(As quite clearly indicated by the text associated with my pic at top-right.)
on February 3rd, 2009 at 7:04 pm
Ok, you win, ONLY because i found the 150MPG GoblinAero!! 🙂
It rocks!
Thanks for the link
Cheers
on February 3rd, 2009 at 8:19 pm
I’d love to try a recumbent bike and trike, but one thing I can’t see them competing with a diamond frame bicycle is being able to sling it over my shoulder and carry it up 2 flights of stairs to my flat.
At least that’s what I did with my 10speed when I was younger.
Maybe a fully carbon/composite recumbent would be light enough?
on February 3rd, 2009 at 9:49 pm
I guess I’ll have to ride a recumbent.
Like I said I had a ride on a “big” 26 inch mountain bike, converted to a single speed. It had been converted to a single speed so he could jump it, but believe me, it was no jumping bike. And I’ve ridden the big jump bikes (they feel like big BMX’s).
It steered slowly, was immensely long.
By the end of the day I had gotten used to it and was putting it through its paces. I was riding it pretty similarly to my BMX, given it did steer a bit slower. Luckily, the friend I borrowed the bike from is pretty much the same height as me, so the bike was fitted well.
I’d be very surprised if I could get a recumbent to handle like a properly fitted 26 inch. I’m not doubting you Julian, but I would be very surprised.
From your response to ducking/weaving/fitting between cars… well… I guess a recumbent wouldn’t be suitable for commuting through the CBD. After all, the major benefit of riding a bike through the CBD is skipping the traffic! But I think it could be fun for a weekend fun ride, especially after my body is dead from BMX…
Look forward to hearing more about your project.
on February 4th, 2009 at 9:48 am
whilst agreeing with James W in regards to CBD driving (its hard enough to WALK on the footpath let alone ride a recumbent trike on the road) but am certainly interested in the idea of the recumbent trike as a touring bike, from where i live there is a largely uniterupted 20km valley with shared footpaths, this is where is see the ‘bent to come into its own.
on February 4th, 2009 at 1:41 pm
This morning I went through my normal commuting ride to work. There are two or three very narrow sections, eg. there is a section of bikepath were some %^* has put a light pole right in the centre of the bike path.
When I ride through these bits on my mountain bike, with flat handlebars, it is a tight squeeze, I have to slow or risk getting the bars caught and flipped off.
On my road bike, which is maybe 10 cm narrower, there is no problem at all and I just whizz through.
Hence having a bike as narrow as possible makes a real difference to me. And having a recumbent that “will have a track only 10cm wider than the handlebars of a typical bike” is going the other way, and would probably require a detour around these more direct routes.
on February 4th, 2009 at 1:44 pm
FWIW, how wide are ‘standard width’ handle bars? I have 28 inch wide bars on my BMX which is considered quite large, sometimes squeezing through requires a bit of creativity.
on February 4th, 2009 at 2:49 pm
I went downstairs and measured all the bikes in my employers bike room, but for some reason today was a very poor haul (usually there are 6 to 8 bikes, both road and mountain).
Ancient Giant road bike, hand assembled by some customizer in Notre Dame, USA: 42.5 cm
Randonneur Mongoose Road Bike: 46 cm
Cell Blade road bikeL 46 cm.
So much narrower than 28 inches, but they are all road bikes.
on February 6th, 2009 at 8:10 pm
In regards to smaller harder seats being uncomfortable, anyone who has ridden long distances will attest, in general, that an anatomically designed seat with little or no padding leads, with practice, to way fewer bum issues. It’s not weight that gets the padding removed. I will agree a large padded seat is way better for the casual rider but I’m sure if I rode a 100k ride on anything but my hard seat I’d die of chafing.
on February 6th, 2009 at 9:31 pm
Mianos – I simply don’t agree.
I have done a tour of a few hundred kilometres on a Brompton upright bike (see http://blog.autospeed.com/2008/06/14/a-riding-holiday/) and it could be termed comfortable only if you know no better.
The last isn’t meant in a nasty way – most bike riders have never experienced a really comfortable bike!
No doubt many get used to it, but that’s a different thing isn’t it…
on February 6th, 2009 at 9:50 pm
When will you be publishing the details of the new trike? I’m keen to find out more!
on February 7th, 2009 at 7:09 pm
When will you be publishing the details of the new trike? I’m keen to find out more!
A fairly long time I think. Am having a lot of very large problems.
on February 8th, 2009 at 8:41 am
What are the problems? I’d like to help. I’m sure many other readers would too. Perhaps this could be the first autospeed ‘open source’ project?
on February 9th, 2009 at 8:39 am
Getting back to the seat hard/softy issue. It seems to me that on a bike, the most comfortable seat depends on your position.
If you are leaning forward, like on a road bike, they you want a thin, hard seat (properly shaped). As you sit more upright (mountain bike, commuter) the ideal seat becomes wider, and softer. If you start to sit back (dragster, pedal forward type design) the ideal seat becomes even bigger and even more padded. And finally with a recumbent you are leaning right back, and the best seat design is verging on an armchair.
The recumbent riders assure us that leaning back in a comfortable chair is far more comfortable than leaning forward on a hard perch, and that sounds reasonable to me. But sticking a big, padded seat on a bike it isn’t suited for won’t work.
on February 9th, 2009 at 1:31 pm
Julian, I was most interested that you mention that rare machine, a front wheel drive delta recumbent. Ahh memories.
A couple of years back a few of us were involved in the HPV pedal prix series. I was involved with my daughter’s school competing at the primary schools level. Although the school already had a couple of greenspeeds and a very old home made rear drive delta we decided to build a new car from scratch and importantly, avoid using any kits to maximise the allocation of competition points. The design we settled on was another delta but this time with the added idiosyncrasy of front wheel drive. We did consider a leaning capability aswell but felt it would make it unnecessarily heavier and awkward to steer. We found very early on when we built a full working mule that a standard 3/8” bike chain could accommodate a wide angle if twist and articulation. Construction of the real one used CrMo tubing with glued in place aluminium bracing, slicks and an 8 speed hub gear set. We could tune the turning circle to 4m if we wanted. It turned out to be very reliable. The car weighed in at about 20 odd Kg, proved to be mildly successful and was quite fast. We had to make a second pair of forks as we mis-calculated the castor resulting in ‘tank slapping’
The only prize we won that year though was a design prize for innovation. The main problem however was that when using 11-12 year old school children the power outputs are not very high so the shear speed was hampered on occasions.
We had a lot of fun though.
on February 9th, 2009 at 1:35 pm
My machine now won’t be a FWD leaning delta. Try doing one with 6 inches of suspension travel – it becomes an absolute nightmare.
on February 13th, 2009 at 10:06 am
The attached website is for a 4 wheeled recumbent leaning vehicle. Looks like a nice concept well put together. I thought it might give you some inspiration.
PS: Thanks for the recent articles on Trev from Uni SA the detail of the build is facinating & shows a very professional looking product is capable of being made with hand building techniques.
Keep up the great work on a fantastic magazinr
on February 13th, 2009 at 11:13 am
Yes, the article on the Trev was great. 5/5