First attempt with SPD's today in 30 mins

omegas

I use SPDs because I like them.

The moral of the story (or this thread ) is that real mountain bike riders, the ones that live, breathe the sport and hobby don’t give a toss what other people are using they just live to ride.

Some people on here need to start enjoying what they do rather than looking at what everyone else is doing or using.

bike-a-swan

cgarossi, I'm not completely sure what you're getting at here-

'If you try to simultaneously pull up and push down with exactly the same force (which is impossible) then the total power exerted will be divided between forcing down and pulling up, combining in the axle to propel the bike forward via the drive train.'

Correct me if I'm wrong, but that supports realman, surely- if you push down and pull up, the two moments around the bottom bracket combine to give more drive. Were you just pushing down, you'd only have half the moment.

RealMan

cgarossi wrote:

The reason why your foot popped out of the cleat is because you cannot apply 100% power into just turning your cranks. The power you are applying is going toward propelling the bike forward.

When I say resistances, there are too many to list. In order to get the bike going forward there are many resistances at work.

Still don't understand what you're saying there.


Basically, my rear foot was pulling up on the pedal. It then released (probably due to worn cleats) and my foot was suddenly pulling up on its own, with nothing to hold it down, it flew up.

And I still don't understand why you are talking about resistances. Or things like "100% power".

omegas wrote:

The moral of the story (or this thread ) is that real mountain bike riders, the ones that live, breathe the sport and hobby don’t give a toss what other people are using they just live to ride.

Some people on here need to start enjoying what they do rather than looking at what everyone else is doing or using.

Two people in an art gallery like two different pieces of art. Are they not allowed to talk to each other about why they like their piece of art more then the other? The only difference is that art isn't a science, where this discussion is. Which means that one side of the argument is right (SPDs).

Thewaylander

The bit that cracks me in this thread, is the people arguing for SPD, were the people areguing against full sus.

People who claimed that having fullsus made it to easy no challenge over bike what ever lol. Now because they have no technique so can't unweight the bike with out being attached there arguing for the technical solution... Oh the fantastic irony

cgarossi

No. It divides total power between the two. It is more effecient, but one leg will dominate the other and cancel the action out.

So if you could pedal with exactly the same power on up and downstroke you would have optimum effeciency. But, if you push down harder, you will not be able to match that action with your upstroke. Try it, I assure you its impossible.

Thats why SPDs make it more effecient, you can releive some of the pressure but apply a force in either direction, but so long as one force is greater than the other it will cancel out.

You can also use SPDs to apply power to the point where an upstroke becomes a downstroke or vice versa, this is where flats fail as you have to rely on your leg moving to a point where you can apply power to the pedal.

RealMan

Thewaylander wrote:

The bit that cracks me in this thread, is the people arguing for SPD, were the people areguing against full sus.

People who claimed that having fullsus made it to easy no challenge over bike what ever lol. Now because they have no technique so can't unweight the bike with out being attached there arguing for the technical solution... Oh the fantastic irony

Not quite sure why you're talking about unweighting the bike and general trail skills and such, as this discussion has nothing to do with any of that. Unless maybe you're just trying to prove that people who ride hardtails are smarter then people who ride full sus?

And to be honest, I find flats make it easier. Better sideways grip, and I can bunny hop better on flats. You can also dab easier, and you don't have to clip in and out all the time. I would ride flats more often if it wasn't for the efficiency and power from SPDs and the better choice of shoes.


cgarossi by your argument, two people pushing a car along a road would be pointless unless they were both equally strong. If one was weaker then the other, him pushing it would make no difference what so ever.

Rethink what you're saying.

cgarossi

Basically, my rear foot was pulling up on the pedal. It then released (probably due to worn cleats) and my foot was suddenly pulling up on its own, with nothing to hold it down, it flew up.

Try doing that while spun out. The effect will be less noticable.

As you approach the apex of the turn, you can't force any more power to the cranks since the crank is upright, all off a sudden, the force of your foot pull upwards moved to the cleat/SPD, which then came away.

Thewaylander

RealMan wrote:

Thewaylander wrote:

The bit that cracks me in this thread, is the people arguing for SPD, were the people areguing against full sus.

People who claimed that having fullsus made it to easy no challenge over bike what ever lol. Now because they have no technique so can't unweight the bike with out being attached there arguing for the technical solution... Oh the fantastic irony

Not quite sure why you're talking about unweighting the bike and general trail skills and such, as this discussion has nothing to do with any of that. Unless maybe you're just trying to prove that people who ride hardtails are smarter then people who ride full sus?

And to be honest, I find flats make it easier. Better sideways grip, and I can bunny hop better on flats. You can also dab easier, and you don't have to clip in and out all the time. I would ride flats more often if it wasn't for the efficiency and power from SPDs and the better choice of shoes.

In any comparison of pedals i believe this is part of the core of the argument.

I like Yee have a relatively high understanding of physics and mechanics and understand the point where power difference is not quantifiable. This only leaves control and obviously being attached to the bike takes less skill i believe its a very relative point as its the only difference.

RealMan

cgarossi wrote:

Basically, my rear foot was pulling up on the pedal. It then released (probably due to worn cleats) and my foot was suddenly pulling up on its own, with nothing to hold it down, it flew up.

Try doing that while spun out. The effect will be less noticable.

As you approach the apex of the turn, you can't force any more power to the cranks since the crank is upright, all off a sudden, the force of your foot pull upwards moved to the cleat/SPD, which then came away.

What? Why are you talking about apex and turns? What??

Thewaylander wrote:

In any comparison of pedals i believe this is part of the core of the argument.

I like Yee have a relatively high understanding of physics and mechanics and understand the point where power difference is not quantifiable. This only leaves control and obviously being attached to the bike takes less skill i believe its a very relative point as its the only difference.

Think of it as road cycling if it helps. We are all talking about efficiency and power transfer in flats and SPDs. This isn't just about which is better. This is about efficiency and power transfer. Nothing else. You might as well talk about which come in the nicer colour schemes as well.

bails87

I've only just started using SPDs and I can certainly feel that I'm using my calves to pedal by pulling up. I simply didn't do that on the flats, I couldn't, if I lifted my trailing foot up, it would lift off the pedal.

However, I only feel this when accelerating or climbing, a lot of the time there probably isn't any difference. But when I'm pulling away from stationary there is a definite 'boost' from SPDs. Now this may be less efficient, just as afterburners on a plane are, but I'm definitely quicker. I don't know if the efficiency loss makes me slower overall though.

But having done the first 'proper' ride on SPDs yesterday, another major, and probably the most obvious advantage, seems to be an ability to control the back of the bike much better.

You could argue this is down to a lack of skill on flats. And fair enough, but then anyone who uses knobbly tyres or suspension is (if someone uses that argument), by the same logic, compensating for their lack of skill.

Now I agree with yeehaamcgee on the dropped/fired bullet and front wheel braking things, and I'm sure I backed him up on them. But I don't see how pulling up on the trailing pedal reduces the force on the leading one.

If people like flats then that's fine, and I'm not saying SPDs are more efficient. But I don't like being told that I'm making up excuses because I feel silly for spending money on something rubbish. I like them. So I'll keep using them for the majority of my rides. That's all that matters. I also like flats, so I'll use those where I'm happier/more comfortable with them than SPDs, again, my choice, and I have to live with the consequences (whatever they may be) of pedal choice!

It's the absolute answers that annoy me: "Flats ARE just as efficient"/"SPDs ARE better"/"You CANNOT pull up" etc etc.

Just let people try them and use what they're happiest with!

cgarossi

What? Why are you talking about apex and turns? What??

I'm sorry if you don't understand.

RealMan

bails87 wrote:

I've only just started using SPDs and I can certainly feel that I'm using my calves to pedal by pulling up. I simply didn't do that on the flats, I couldn't, if I lifted my trailing foot up, it would lift off the pedal.

However, I only feel this when accelerating or climbing, a lot of the time there probably isn't any difference. But when I'm pulling away from stationary there is a definite 'boost' from SPDs. Now this may be less efficient, just as afterburners on a plane are, but I'm definitely quicker.

Exactly, +1

cgarossi wrote:

I'm sorry if you don't understand.

That's ok, maybe you would like to try to explain your ideas again, more clearly?

Thewaylander

[/quote]Think of it as road cycling if it helps. We are all talking about efficiency and power transfer in flats and SPDs. This isn't just about which is better. This is about efficiency and power transfer. Nothing else. You might as well talk about which come in the nicer colour schemes as well.[/quote]

Uhm then go discuss it in a road forum

bike-a-swan

bails87 wrote:

Just let people try them and use what they're happiest with!

But they can't be happiest because they AREN'T RIGHT! I'd like to add I'm interested in the debate from a technical perspective only!

joshtp

i know its a total preference thing, but keep going for a while, get used to them properly... it took me a while and i like them now... i not a die hard spd advocate, flats are great too, but at least on my main XC bike, i like them

Thewaylander

Bails mate

I think what Yee and myself are trying to point out is that, we get annoyed with people telling us there more efficient when looking at actually measured evidence and the physics you can pretty much prove that isn't true.

If you said SPD's are ace they just make me feel more secure/incontrol then fine i can accept that, but then if someone on SPD's on a hardtail tells me I'm overbiked on my FS bike and lack skill i'm gonna hit on there pedals to show the hypocracy

bike-a-swan

at what point then do you become underpedalled?

cgarossi

That's ok, maybe you would like to try to explain your ideas again, more clearly?

It doesn't matter.

Each to their own. I like SPDs.

RealMan

Thewaylander wrote:

I think what Yee and myself are trying to point out is that, we get annoyed with people telling us there more efficient when looking at actually measured evidence and the physics you can pretty much prove that isn't true.

Yes you can.

cgarossi wrote:

That's ok, maybe you would like to try to explain your ideas again, more clearly?

It doesn't matter.

cgarossi

Ok now you're just a cunt. :roll:

bails87

Thewaylander wrote:

Bails mate

I think what Yee and myself are trying to point out is that, we get annoyed with people telling us there more efficient

As I said:

bails87 wrote:

It's the absolute answers that annoy me: "Flats ARE just as efficient"/"SPDs ARE better"/"You CANNOT pull up" etc etc.

Although I will dispute the point that you cannot pull up. You can. Whether it makes any difference is another matter, but you can pull up so to say that it's "impossible because the riders weight has to be supported somewhere" is wrong.

RealMan

bails87 wrote:

Although I will dispute the point that you cannot pull up. You can. Whether it makes any difference is another matter, but you can pull up so to say that it's "impossible because the riders weight has to be supported somewhere" is wrong.

+1

cgarossi wrote:

Ok now you're just a ****. :roll:

Thewaylander

No you can't realman,

All i have seen from the SPD camp is terrible mech/physics which is why Yee left. You are 18 fella and sorry but if you not in an advanced uni level super brains class, I'm going with the people like myself and yee who have further education in the field.

The fact you state you can with no back up is no claim at all.. your arguing blindly just hoping your opinion will win because everyone else will give it because your just to annoying stuborn to listen to anyone else/.

Thewaylander

Indeed bails but specifically i said effieceny not pulling up who cares where the power is applied.

We are talking about force out compared to force in and energy consumed type of things, and there is just no way to support SPD's are more effeicent. So it's an annoying argument against flats.

cgarossi

I don't have a degree in physics but I do have some idea (more than most probably) and I may be flawed in some areas but I beleive im on the right track.

If someone wants to prove me categorically wrong then I will accept it and move on. Suffice to say, i'm trying to agree with Yee here.

That said, I prefer SPDs wether they are more effecient or not.

bails87

Thewaylander
But you can! Just yesterday I was riding along with one leg doing nothing (not on the pedal) and the other one powering the pedals through the whole revolution.

Was it pointless? Yes.

Did I look silly? Yes!

Was it less efficient than pedalling with 2 legs? Most probably

But was I pulling up on the pedal? Yes.

Does pulling up on the pedal improve efficency? I don't know

Do SPDs actually make you pull up much? I don't know

Those last 3 points are crucial. You can pull up, but you might not necessarily do it, and even if you do it might not be of any help.

Kubase

When I bought my 5:10s the bloke in the shop told me that SPDs were 37% more efficient, and that he would beat me in any climb if I was using flats no matter how fit I was, despite him being 41. I think this is indicative of the only real problem, which is people new to the sport being pushed into a certain direction when pedal type is such a personal thing.

RealMan

This terrible mechanics and physics you speak of, why has no one taken it apart yet then?

The fact is, the physics involved is physics a 15 year old could understand. Its painfully simple.

I've backed up my theory with plenty of evidence, and so have other people. My experiments would prove it. You're just in denial I think.


bails87, it really comes into its own once you get used to it. Then when climbing (particularly on steep climbs), sprinting, and accelerating, and when going along at a lowish cadence in a high gear it really does improve your riding.

cgarossi

The only areas I can see SPDs having a benefit are:

1. The transition phase where upstroke becomes down and vice versa, where you can physically pull the pedal around. Providing some benefit.

2. Stability when you're being shaken about on the bike.

3. Ability to apply power over the aformentioned shakey/rocky areas without your feet coming off the pedals.

cgarossi

The fact is, the physics involved is physics a 15 year old could understand. Its painfully simple

Then you have a problem.