What do you all think about these slightly strange things?
Recently I have become quite interested in them, and the thing below is very tempting indeed:
(http://www.bentrideronline.com/features/06PREVIEW/OBXLOW.jpg)
I am interested mostly due to the speed aspects of them, it seems that they are naturally a much faster vehicle due to the aerodynamics although they aint quite so good up the hills apparantly.
I quite like some of the trikes, too - practical and very fast!
The only thing I dont like is some of them are RIDICULOUSLY expensive - the one pictured there in the best trimmings comes in around Ã,£1500 which isnt bad at all, as far as some of these things go, although its still expensive, really. :shock: but it seems common for these things to fetch Ã,£3000 / Ã,£4000 prices :shock: :o
They are strictly for bearded college professors that still wear lycra covered helmets from 87.
I prefer ass hatchets.
They do have a strange image, thats for sure - I am not sure I would welcome it, tbh.
The riders (who call themselves pilots) call the bikes bents and its all a little strange.
buuuuut,.......... they are sooooooooooooo fast :D which makes me all too tempted!
I suppose this is why they are at rip-off prices - they appeal to a niche of the old bearded types, and the "want to go as fast as possible" types - the bearded chaps build their own out of old washing machines and hairdryers, whereas me, completely lacking an engineering degree will fork out, within reason :roll:
One of my dads mates had one. He sold it after a while, said it was good fun but insanely dangerous; youre nicely out of the line-of-sight of drivers and hence theyre completely lethal apparently.
I dont generally cycle nearby busy roads
tend to keep to quiet B-roads and the like, as I dont commute or do anything like that :)
I think ill do some more research on them before making any decisions
Quote from: snellgroveWhat do you all think about these slightly strange things?
Recently I have become quite interested in them, and the thing below is very tempting indeed:
(Image removed from quote.)
I am interested mostly due to the speed aspects of them, it seems that they are naturally a much faster vehicle due to the aerodynamics although they aint quite so good up the hills apparantly.
I quite like some of the trikes, too - practical and very fast!
The only thing I dont like is some of them are RIDICULOUSLY expensive - the one pictured there in the best trimmings comes in around Ã,£1500 which isnt bad at all, as far as some of these things go, although its still expensive, really. :shock: but it seems common for these things to fetch Ã,£3000 / Ã,£4000 prices :shock: :o
a fair few people in manchester use them, they look strangely comfortable, but you do look like a todger on one...
dont fit on trains, they dont fit in bike racks they look odd so will be targets for theft and vandalism.
Crap up hills because you cant just stand and mash the pedals, your stuck laying down.
They look cool, but ultimately completely crap unless your living in holland :D lol.
excellent up hills apparantly, apart from the increased weight
one of the first things I looked at, as where I live is extremely hilly.
You can push into the chair and really push those pedals around :)
apparantly the overall strategy for hill climbing is to spin, and spin fast though as you can do your knees a mischief by pushing so damn hard.
Thing is on a normal bike you can only push as much as you weigh - otherwise you go upwards. This bike, you can push and theres a chair behind you.
I dont mind about trains... or bike-racks so much. Theft and all that, yes.. definately one to insure. need to insure my Scott as I am always conscious of that shiny carbon fibre & decals being an absolute magnet to thieves! :(
reputedly not so hot on city streets though. and not good if you have joint problems like I do.
Quote from: snellgroveexcellent up hills apparantly, apart from the increased weight
one of the first things I looked at, as where I live is extremely hilly.
You can push into the chair and really push those pedals around :)
apparantly the overall strategy for hill climbing is to spin, and spin fast though as you can do your knees a mischief by pushing so damn hard.
Thing is on a normal bike you can only push as much as you weigh - otherwise you go upwards. This bike, you can push and theres a chair behind you.
I dont mind about trains... or bike-racks so much. Theft and all that, yes.. definately one to insure. need to insure my Scott as I am always conscious of that shiny carbon fibre & decals being an absolute magnet to thieves! :(
Except up hill you will be working AGAINST gravity as opposed to WITH gravity. Each push of the pedal will be pushing you into your seat yes sure, but you will only be pushing with the strength of the muscles in your legs, as opposed to leg muscles + weight.
Spinning sure... but you can spin with more force on an upright.
Quote from: M3ta7h3adExcept up hill you will be working AGAINST gravity as opposed to WITH gravity. Each push of the pedal will be pushing you into your seat yes sure, but you will only be pushing with the strength of the muscles in your legs, as opposed to leg muscles + weight.
Spinning sure... but you can spin with more force on an upright.
Not quite right, your weight is all that is doing any work in that situation on a normal bike, your muscles are just lifting your body and you may not be able to use your full capability. With one of these you are pressing between two fixed points and can thus apply more energy to the pedal.
Not really considering that its not two fixed points.
Its not even 1 fixed point on an upright.
What snellgrove is saying is that you can use your muscles to power up the hills.... im not disputing this.
What I am disputing is that upright bikes allow you to fully harness gravity to your advantage. Instead of relying purely on muscle power to get you up that hill, I can rely on my weight as you correctly say to power up that hill, combined with my strength.
Strength doesnt matter as the same amount of force will be applied via the muscles in any situation upright vs recumbent... why? because the pedals move. Your maximum force applied via muscles = the maximum resistive force of the pedals.
And your also forgetting that just holding the handlebars prevent the lifting of your body past a certain point. It is after all why you pull on the bars as your climbing a hefty hill.
Except on an upright its as follows:
Weight + Muscular Force = Maximum resistive force of pedal.
On a recumbent:
Muscular Force = Maximum resistive force of pedal.
So you have a harder time of it when climbing hills. Its physically an impossibility for a recumbant to be more "efficient" at climbing hills. FC9K im sure will kinda understand my gibberings! :)
With that type of logic, youre just the kind of geek that usually ride the dang things. :mrgreen:
/me rides away on my manly Pedersen. (http://www.dursley-pedersen.net/modern_pedersen/copenhagen.shtml)
:mutley:
I see what you are saying there, M3ta.
I suppose the best thing is to have legs that can supply a whole heap of force
Theyd have to be developed into tree-trunks to beat gravity*mass of body + leg-force for a normal diamond-frame bike.
I suppose one benefit is that they have more gears. My racer only has 18 and on the 10-mile loop there is this real killer of a hill, a genuine switch to 1st gear and still struggle away and need a rest at the top (or if you dont, keep going and not change to 2nd, you cant bear it for a few mins) kinda job. quite a few times Ive done that ride fast and had aching lungs / throat the next day or so due to the stress I put on them going up that one :lol:
Theres also another killer hill (but its only about half as long, but same steepness) at the end of pretty much every loop I do :( really gets the legs burning
So in these instances, I could drop down a few cogs and be more
efficient - and probably go at the same speed up them :)
I might be wrong though, who knows.
The shop that sells the bike pictured in the 1st post is a couple of hours away :( nearest shop that sells bents in general is about 1.5 hours away and they are all Ã,£3k+
the shop that sells the Optima as pictured though, offer big test-rides (you pay Ã,£40+ for a half days test ride which is refunded if you buy one of the bikes.) so I might give that a go, to get a really good feel of one :) I get the impression it is FLAT up there though :lol:
clicky (http://www.futurecycles.co.uk/tuition.html)
QuoteThe Zen of recumbent riding...................... relax and spin.
If you would like to discover what it would be like to ride a recumbent bike or trike we offer expert tuition and hire. Our shop is only a few minutes from the Forest Way, a 12 mile traffic free section on Route 21 of the National Cycle Route. This old railway line meandering through the Medway Valley is ideal for those experiencing riding a recumbent for the first time. If you have time to spare we also have routes taking you through the lanes of this beautiful part of Sussex.
Most people can manage to ride a recumbent after a few minutes practice. However, the technique of riding a recumbent is different to conventional bikes so personal tuition will reduce the learning curve and make the experience more enjoyable. Those considering buying will benefit from the opportunity to try several different recumbents and if they decide to buy within 60 days we will refund the course fee.
yeh not knocking you for wanting one mate :) they look cool!!! :) I want one too :D lol but I dont agree with them being better for hills :P lol.
Route 21? I use Route 4 and Route 8 to get to work and back :D
No "route X" near me at all that I am aware of :(
The nearest thing I have to a flat, straight bit of tarmac lacking cars is the Bournemouth promenade.
its good apart from the pedestrians - they probably dont like me much, and I dont like having to dodge them or their dogs either. Tend to go there later rather than earlier, so theres less people :) during June it was nice, as its too cold for 90% of people to be standing around but its just fine for 20+ mph blatting along there :D
One other cool place nearby (around 6 miles from me) is in Poole Park:
view here - Google Earth (http://snellgrove.googlepages.com/tarmaccircleofpain.kmz)
its a nice little circular lap and you can do it in the mid to high 50s before collapsing on the grass at the end - its crazy as theres always a headwind for at least one part of it which kills you :D
I think a Recumbent will be best for this sort of thing, seems they are built for high-speed flat-land stuff really, because of their aerodynamics. Theres plenty of dead-quiet B roads near me, which most of my loops are composed of :) most involve hills, but the 15mile loop we have has a 2 mile stretch of flat lovelyness where much slipstreaming ensues!
The one pictured is 9kgs - not bad really, my plastic as Max calls it, bike is only 1 / 1.5 kg less :lol: So hills wont be too bad all in all.
what google earth do you have. I want to plan a route decently I think.. need something other than the 10mile commute to work as its getting boring. Its lovely landscape but you take it for granted after youve seen it about 9 times in a week.
Google Earth, Beta 4.
Does that not worky?
theres a way of pointing google maps at a kml file, and itll go there too :) but I cant remember how to do it.
Quote from: M3ta7h3adFC9K im sure will kinda understand my gibberings! :)
Your maths is wonky.
Quotesame amount of force will be applied via the muscles in any situation upright vs recumbent... why? because the pedals move. Your maximum force applied via muscles = the maximum resistive force of the pedals.
^ Wrong in all cases except for where youre travelling at constant speed.
QuoteExcept on an upright its as follows:
Weight + Muscular Force = Maximum resistive force of pedal.
Hmmsk. I know what youre getting at, but youve got to remember that "Muscular force" will be different for each bike; youre in a far more efficient position on a bent so youll be able to deliver a hell of a lot more power. On an upright, the role of your arms is purely to try to keep your body in a fixed position so you can pedal with your leg muscles. Youll evidently have more luck pushing against a solid surface since you wont dissipate as much energy in flex etc, and the chair will hold you in the right position with much more stability than your arms would.
All in all I reckon youd have an easier time of it on a recumbant, purely due to the line of action of the force youre supplying going roughly through your back into the chair. On an upright, youre applying force sort of at an angle, so you can kinda picture you getting less "useful force" out of it. Maybe.
You could prove this experimentally, but I cba.
[edit] YARR, cracked the badger.
You cant get any usefulness out of your weight on an upright. Think of an energy argument; over half a crank rotation you can put energy into the cycle purely by letting your weight turn it, thus your COG drops. Next half rotation though, youre shafted. Your COG cant keep getting lower and lower, so you have to actually *pull yourself back up* with your leg muscles. Since over the course of a ride your COG stays at the same vertical position relative to the bike, YOUR BODY WEIGHT HAS DONE NO NET WORK. (nb this is dependent on whether you treat work as a vector quantity, but it should be obvious what I mean).
Oh and COG = centre of gravity.
except surely for the other half of the cycle your other leg (weight) is pushing down as well, which brings up the other leg naturally. In fact on an upright its possible to solely use the muscles in your back to facilitate a shift in weight position (rather than applying a direct force) and maintain a pedalling motion.
Quote from: M3ta7h3adexcept surely for the other half of the cycle your other leg (weight) is pushing down as well, which brings up the other leg naturally. In fact on an upright its possible to solely use the muscles in your back to facilitate a shift in weight position (rather than applying a direct force) and maintain a pedalling motion.
M3 invents a perpetual motion machine :roll:
Get out on your bike and try it. I guarantee you you will have to lift your own weight on the pedal to complete a full revolution of the pedals. The only way you can avoid using your leg muscles to drive the pedals is if you wait until both cranks are horizontal before switching your weight over. And the cranks will obviously only ever reach that position with you standing on them if a) youre going downhill in which case its irrelevent or b) total rolling and drivetrain resistances = 0, which is clearly not possible.
Not really considering you have to input energy into it.
The mere act of pushing down means your pushing the other leg up.
Anyhows physics of no physics, Ive spent the last few days reading posts in a recumbants thread on a biking forum. Appears recumbants are indeed slower up hill. :)
Quote from: M3ta7h3adThe mere act of pushing down means your pushing the other leg up.
...and then you have to straighten the leg. Which means holding your weight on it. Think about it! If you keep it bent, then what happens?
aye I see what your getting at, and at TDC and BDC you will be applying 0 force or rather the horizontal component will be zero, itll take either weight movement or muscular force to get it to move from that point :)
But momentum often will be able of carrying the weight applied on a pedal around further than the TDC and BDC areas, at which point a slight shift of weight will mean that youll continue to pedal, without requiring any further exertion. (if on a frictionless flat plane, in the real world yes some exertion will be needed to recover from the losses in transmission, and friction however not as much exertion as a recumbant :))
I think were both saying the same things maybe :D
Quote from: M3ta7h3adaye I see what your getting at, and at TDC and BDC you will be applying 0 force or rather the horizontal component will be zero, itll take either weight movement or muscular force to get it to move from that point :)
But momentum often will be able of carrying the weight applied on a pedal around further than the TDC and BDC areas, at which point a slight shift of weight will mean that youll continue to pedal, without requiring any further exertion. (if on a frictionless flat plane, in the real world yes some exertion will be needed to recover from the losses in transmission, and friction however not as much exertion as a recumbant :))
I think were both saying the same things maybe :D
No. Were not. Because you seem to be conveniently forgetting the fact that at TDC, one leg is bent and the other isnt. And like it or not, you cant just "shift your weight" to do another half-stroke. You have to straighten the leg, and surprise surprise you have to lift your weight to do so.
No because your forgetting that when you straighten the bent leg, your straight leg will become unbent.
Apply force to raise leg out of BDC and get leg down out of TDC by a few degrees and voila... your weight and balance will take over. Your body weight is not distributed equally on both sides of the bike, the one leg (the one that is rising) will be carrying less weight than the one on the descending side.
damn physics nerds.
(http://www.ics.uci.edu/~eppstein/pix/j4p05/Recumbent-m.jpg)
;)
I dont mind if its not quite as quick up a hill.
its all about the amazing speed along the flats and the like
Quote from: M3ta7h3adApply force to raise leg out of BDC and get leg down out of TDC by a few degrees and voila... your weight and balance will take over. Your body weight is not distributed equally on both sides of the bike, the one leg (the one that is rising) will be carrying less weight than the one on the descending side.
I feel like Im banging my head against a brick wall here. I say again, go and try it. Youll find your error pretty quick even if the whole "conservation of energy" thing doesnt wash with you.
Quote from: funkychicken9000Quote from: M3ta7h3adApply force to raise leg out of BDC and get leg down out of TDC by a few degrees and voila... your weight and balance will take over. Your body weight is not distributed equally on both sides of the bike, the one leg (the one that is rising) will be carrying less weight than the one on the descending side.
I feel like Im banging my head against a brick wall here. I say again, go and try it. Youll find your error pretty quick even if the whole "conservation of energy" thing doesnt wash with you.
I had the same problem with dave and space travel some time ago, people dont notice that when they straighten their leg from a sitting position is different from going up hill when you are going to be standing in order to maximise your weight on the pedals. In the first you dont move your body up visibly, even though that is what you are pushing against. in the second you straighten the bent leg at the top and there is a delay before the pedals turn, which is what we have been going on about, and in that case you do lift your body reducing efficiency.
I dont need to try it. Though even just pedalling a bike you will be doing this.
Conservation of energy applies to my case.
You convert potential energy in the one leg (starting just forward of TDC), to kinetic (as it moves) and potential (by lifting the other leg with the pedal).
There will be energy loss (Through friction on bearings and air resistance) but this is why you will need to use muscles to apply extra force to keep the motion going.
After the half motion (taking one leg from TDC to BDC, and the other vice versa) inertia carries the leg through the areas in which no force can be applied (if this wasnt true then youd come to a halt after pedalling one half revolution)
This brings you back to the beginning on the other leg/side.
Imagine viewing the motion from behind... youll see a pendulum motion, rocking back and forth across the top bar. That would be your center of mass. You will put the center of mass over the leg with the TDC position, and gradually swing it over to the other side as the positions of the legs swap places.
With the pedals horizontal your center of mass will be directly over the crossbar 50/50 each way.
this positioning of your mass is what I mean by using the weight of your body to power the bike.
Recumbants have no way of allowing you to use your weight to aid your pedalling. Sure they provide a solid support for you to apply force from, but all that force requires use of your muscles.
Uprights merely require muscles as supplemental input to a pedal motion.
the only reason youd need to straighten your legs at the top of a pedal motion would be because your starting off and need to start with your weight on the other side of the bike that your naturally on. orrrr... your using poor pedalling technique whilst not clipped in.
When a leg is straight, all weight is on that leg.
to start it on its up journey you dont need to "lift it" just sway your center of gravity over to the bent leg and the pedal will drop down as the pedal becomes more heavily loaded (more force is applied), lifting up the bent leg. Easy.
The way serious describes cycling whilst out of the saddle, hed have us all stumbling instead of pedalling in nice controlled circles.
Without wishing to appear arrogant, I know my fair share of dynamics. Id like to think I know a little about conservation of energy too, having spent the last two years of my life solving problems just like this. The internets a tricky medium to convey this over as most of mechanics relies heavily on diagramatic methods. But Ill do my best and write one more paragraph on this.
Work done = force x distance moved in direction of said force.
In this case youre talking about the benefit of using weight. So, youre talking about using your potential energy (as an object high up) as a power source. However, since at the end of a ride your body is in the same position it started out at, the total potential energy is the same as it started at. Consequently, any energy "given out" by using your weight on the pedals must be exactly equal to the energy used up to get it back to its initial state. And thusly we have proved that the weight doesnt directly contribute to the energy put into the pedals, only to how well you stay rooted and consequently how hard you can push them round. And obviously a recumbent is better at this. QED etc etc, Im f***ing off to bed.
In order to release energy a body has to drop though, yours remains at the same point, all the energy used comes from your leg muscles. moving your weight just balances it over the bike. Unless you pull down on the handlebars you cant increase the force over the actual weight of your body which is what I was getting at, with a recumbant you can use all the muscle strength available.
I have seen one that you can use your arms to pedal with as well as your legs.
Quote from: funkychicken9000Without wishing to appear arrogant, I know my fair share of dynamics. Id like to think I know a little about conservation of energy too, having spent the last two years of my life solving problems just like this. The internets a tricky medium to convey this over as most of mechanics relies heavily on diagramatic methods. But Ill do my best and write one more paragraph on this.
Work done = force x distance moved in direction of said force.
In this case youre talking about the benefit of using weight. So, youre talking about using your potential energy (as an object high up) as a power source. However, since at the end of a ride your body is in the same position it started out at, the total potential energy is the same as it started at. Consequently, any energy "given out" by using your weight on the pedals must be exactly equal to the energy used up to get it back to its initial state. And thusly we have proved that the weight doesnt directly contribute to the energy put into the pedals, only to how well you stay rooted and consequently how hard you can push them round. And obviously a recumbent is better at this. QED etc etc, Im f***ing off to bed.
It clicks ;) lol. Fair nuff mate :D I gets ya.
chucksbikes.com has a cheapie bent for $499. :lol: