How much more effecient are SPD's compared to flats?

and in general I have a smooth, circular pedalling motion

I believe mine is square but I can't get the cranks to fit it 🙁 What mastermind invented unsmooth, uncircular pedalling ? I christen it Poddotosh 🙂

Come now simon, even you know that it dosn't describe the physical shape your feet trace as you pedal, but where you apply torque and where you don't.

thanks for that wonderful diagram of a foot 🙂

I also love the mixture of Imperial and SI units 🙂 – though lb-foot is strangely appropriate 🙂

Other shapes are availible.

If I understand that diagram correctly, the user either is not using spds or is deriving very little benefit from them. Which is it? 🙂

Dunno, it was the only small pic of a spin scan I could find with a quick google. The others were huge.

I seem to recall some interesting ones from q rotor users in last years TdF, but I don't care enough to find them.

the user either is not using spds or is deriving very little benefit from them. Which is it?

I think it reflects the fact that you cannot pull up very much… with flats the left hand lobe would be absent and the right one tangent to the centre.

I believe mine is square but I can't get the cranks to fit it What mastermind invented unsmooth, uncircular pedalling ? I christen it Poddotosh

You know what I mean even though you make out you don't, but of course it's impossible to argue with you once you have a bee in your bonnet, isn't it? 😉

But I'll have a shot anyway…

Unsmooth – People who bob up and down all over the place and mash 'hard' on the pedals (It really shows on FS bikes) without going any faster than those sitting nice and still and pedalling smoothly right next to them.

Smooth – The others I mentioned above, right next to the unsmooth ones!
😛

There's a definate technique to pedalling smoothly. I'm OK, not brilliant, and if I think about it and try hard, I get a bit better. Ask a roadie, they know all about that sort of stuff. 😀

When I'm pedalling in the saddle just mooching along I don't pull up much. If I'm stood up on the pedals riding up a steep hill, partic if I'm on a SS, I tend to *just* pull up, the only push down component is my weight on the retunring leg. But I've done this enough that my 'pull up' muscles are well developed. It seems pretty sucessful, I can ride up absurdly steep stuff anyway.

The only time I pedal in smooth circles (or, for simon, try to apply torque evenly throughout the stroke) is during road sprints and TT's. I try to avoid those though.

try to apply torque evenly throughout the stroke

That's the best way I've ever seen it described ADH, thankyou. 🙂

Hey, no doubt someone will be along to tell me I've got it completely wrong shortly.

I'm not sold on the fact they're any more efficient for 'normal' riders anyway. I just know what I prefer, or have come to prefer. I can't ride for toffee in flats anymore.

People who bob up and down all over the place and mash 'hard' on the pedals

and yet, with motocross bikes, singles, with the least smooth power delivery, work best ? I wonder if it really matters anyway – there are pedals, and you push them to make the bike go & any variations are integrated and smoothed by the inertia of the bike and rider.

Ask a roadie, they know all about that sort of stuff.

I only throw things at roadies

try to apply torque evenly throughout the stroke

I'm mostly looking at girls' arses and trees and rocks and clouds and stuff. Also I doubt if uniform torque is either possible or even desirable.

Ditto, regretable lack of girls arses on my rides though.

They're more efficient at keeping skin on my shins, I can tell you that for free.

Aye, i mainly switched over becuase I was loosing the pedals in the rough stuff far too frequently, and was too lazy to adapt my technique.

and yet, with motocross bikes, singles, with the least smooth power delievery, work best ? I wonder if it really matters anyway – there are pedals, and you push them to make the bike go & any variations are integrated and smoothed by the inertia of the bike and rider.

Different thing altogether. And a single has a very smooth power delivery, (which can't be altered) compared to 'big bang' 4 cylinder engines (e.g. Yamaha Moto GP engine) and the uneven firing order of a Ducati V-twin. That's all to do with allowing the tyre to regain grip between closely spaced 'bangs' rather than a 'screamer' engine which never lets it recover. And remember they're dealing with 210bhp and 300+ Km/h not the 1-2 bhp a human puts out.

To magnify the effects on an MTB, go ride on some ice and see which works best – Smooth or unsmooth….. 🙂

I think it reflects the fact that you cannot pull up very much…

Actually shows that the amount of work you can do (reflected by the area of the left hand lobe) is about 1/3 larger with spds, meaning max force applicable is larger and torque transfer is more constant. Also shows that you could effectively reduce the size of the right lobe, maintain the size of the left lobe and therefore match the same size as the right lobe alone, in which case sharing the climbing duty across multiple muscle groups to help reduce muscle fatigue. Pretty conclusive really. And exactly why these plots exist!

in my experience, the only thing they make you more efficient at is falling off at junctions when you forget you have them on

Ok if you wanna ride flat pedals and tell us you are just as efficient go ahead.

But for those of us in the real world clipped in is quicker, more efficient and for grown ups. Doesnt matter how good you are at pedalling or how big your leg muscles are.

Clipped in for SS , Cyclo cross , xc , downhill and freeride.
Flats for the BMX in the skatepark and maybe the odd DJ action to.

Clipped in. Dont **** about on flats if your wanna go fast.

And a single has a very smooth power delivery, (which can't be altered) compared to 'big bang' 4 cylinder engines

I don't understand how you can think that – a 4 stroke single has one power stroke per two revs, where a 4 cylinder engine has 4 and so is much smoother.

Actually shows that the amount of work you can do (reflected by the area of the left hand lobe) is about 1/3 larger with spds

my estimate from that diagram is 15% not 30%…

meaning max force applicable is larger and torque transfer is more constant.

yet the diagram shows constantly changing torque ?

Also shows that you could effectively reduce the size of the right lobe, maintain the size of the left lobe and therefore match the same size as the right lobe alone, in which case sharing the climbing duty across multiple muscle groups to help reduce muscle fatigue

well, you don't need a diagram for that, but matching the push to the pull just reduces that overall power output. But is there any such thing as muscle fatigue ? Isn't it just when you run out of fuel due to metabolic limits ? I know when my legs get tired, if I have a little rest they work again.

But for those of us in the real world clipped in is quicker, more efficient and for grown ups

well, I envy you grown up real worlders while I languish in 2nd adolescent fantasy. I think.

So, to summarise. No one really knows but think whichever they do is best….

Try both and decide for yourself.

No one really knows but think whichever they do is best….

my position is scepticism. There have been a lot of ad hominem arguments of dubious credibility.

well, I envy you grown up real worlders while I languish in 2nd adolescent fantasy. I think.

they say ignorance is bliss dude. keep on trucking.

Only messing with you dude. As long as your happy with your set up. Just making statements that are blatantly male cow pooh leaves you open to banter. Which is what a thread like this is all about.

Just making statements that are blatantly male cow pooh leaves you open to banter.

which ones ?? And if so, how do you know better ?

To magnify the effects on an MTB, go ride on some ice and see which works best – Smooth or unsmooth

and are we to base our riding techniques on what works best on ice ? Surely holding one's breath is less than ideal in non-icy conditions ?

0%
for a start, you have to say efficiency of what
but for most of us, the limit to the power we can output is cardiovascular, not muscle power, so the pedals make no difference

having seen someone fall off last week at 2mph and get a spiral fracture of the upper arm due to brand new cleats (which I'd seen him adjust at least 3 times) not releasing I'm dubious of the advantages of spuds!

I saw someone once get crapped on by a bird and it actually hit their head because he wasnt wearing a hat. Im never walking outside bare headed.

and yet, with motocross bikes, singles, with the least smooth power delivery, work best ?

so relevant here.

lets face fact here sfb . if you turn up to 90% of cycling race types wearing flats and telling people they are just as efficient as spds you will get some looks of distain and people will give you the bird as they go past you spinning smoothly up a hill whilst eating their banana with the other hand.

But if you dont race and dont mind having to put in more effort than clipped in riders fair play.

Lets face fact here sfb

I suggest it's unsupported conjecture…

if you turn up to 90% of cycling race types wearing flats

I would never try juvenile activities like racing when there is totty to ogle.

But if you dont race and dont mind having to put in more effort than clipped in riders fair play.

but no one has adduced any evidence for improved efficiency, only for allegedly smoother power delivery (which might actually be worse). In purely mechanical terms, provided one's foot doesn't slip off the pedal, the efficiency of power delivery is the same, and I don't think anyone knows if there is a measureable benefit to pulling up over pushing down harder, other than perhaps psychological.

Totty to ogle.

Fantastic. Girls love it when guys leer at them. It makes them just wanna jump straight onto your lap and say,' take me home with you, you flat pedalled leerer'.

I can see you would never change your opinion dude. Its all good.

clipped in?
you ****!

Girls love it when guys leer at them. It makes them just wanna jump straight onto your lap and say,' take me home with you'…

they don't seem too put out:
click pic for bigger

I can see you would never change your opinion dude.

I haven't anything to base an opinion on yet, just a lot of poorly founded guesses – hence my scepticism. As it happens, I don't care much about the answer, as spuds make my knees hurt, and I don't care who's in front of who… however, I'm fascinated by the things people will say to support their arguments 🙂

I used to find when I used spd's that if I was getting a bit of leg ache I could shift to pulling more, or pushing more depending on what felt less painful. Energy consumption and output might have been the same, but a leg's made up of more than one muscle.

Ok if you wanna ride flat pedals and tell us you are just as efficient go ahead.

But for those of us in the real world clipped in is quicker, more efficient and for grown ups. Doesnt matter how good you are at pedalling or how big your leg muscles are.

Clipped in for SS , Cyclo cross , xc , downhill and freeride.
Flats for the BMX in the skatepark and maybe the odd DJ action to.

sam hill thinks you are a d i c k

sam hill thinks you are a d i c k

Oi! Don't pick on da kidz!! (ooops, I mean "grown ups" )

simonfbarnes – Member

I also love the mixture of Imperial and SI units

I think you will find that they are all standard units just a mix of metric and imerial.

I think that the stiff shoes make a big difference rather than they type of pedal but don't care what others use and only care about mine.

simonfbarnes – Member

To magnify the effects on an MTB, go ride on some ice and see which works best – Smooth or unsmooth

and are we to base our riding techniques on what works best on ice ? Surely holding one's breath is less than ideal in non-icy conditions

Smooth power transfer from the wheel to the ground is the most efficent and as ice has a very low coefficent of friction you have to be very smooth. The smooth delivery of power is why a car/motor bike etc slip their clutchs when pulling of as fast is possible if they didn't do this all they would do is spin the power away.
There is going to be very few if any instances on a bike where you would want or need to spin the rear wheel.

To answer the original question – I'm sure I read a study on this using crank power meters, and it was something like 2% more efficient than spinning well on flat pedals, basically for maximum efficiency, there was no pulling up, just unweighting the upward pedals.

Having said that, on spds, it is very very easy to spin well compared to flats, as they pull your feet round nicely and teach you to move your feet in nice circles. But you can develop a very efficient spin on flats with practice.

Joe

I think you will find that they are all standard units just a mix of metric and imerial.

Système International d'unités is based on metres, kilos and seconds…

Smooth power transfer from the wheel to the ground is the most efficent

how do you know ?

and teach you to move your feet in nice circles

it would be a good trick to move you feet not in a circle while keeping them in contact with a pedal that was…

Smooth power transfer from the wheel to the ground is the most efficent

how do you know ?

Have you ever whitnessed a train where the regulator is opened to fast?
Have you ever seen an unbalanced washing machine spin up, thats a non smooth power delivery as it takes more power/effort to move it.
There are plenty of walking machine efforts that shake them selves to peices when they try to move.

The smooth delivery of power is why a car/motor bike etc slip their clutchs when pulling of as fast is possible if they didn't do this all they would do is spin the power away.

Mind you i think sfb would argue that black was white just becuase.