Why leg strength doesn't matter, that much, for road riding - a technical answer

[GrasB]

When you start to look at video of you in various states of power production & riding position you see all kinds of interesting things. If you were to just look at the pedal force plots you'd think that I was pulling up on the back pedal when sprinting hard but actually I'm not I'm just bracing against the pedal & all the force is coming from the front leg. You get a very similar plot when I'm up at 350-400w, however if you look at video you can see that I'm actually pulling up with some force on the pedal. If only when you combine pedal force plots & video footage you can actually see what's going on.

 

[Rob3rt]

What level do you race at GrasB? Just curious, since you seem to do a lot of analysis etc and have coaches and go training in spain or italy or wherever etc.

 

[fenlandpsychocyclist]

Thanks for the interesting read black'n'yellow.

So if mountain bikers have the smoothest pedal action, maybe i'm already there as i do
lots of offroad stuff?

 

[GrasB]

What level do you race at GrasB? Just curious, since you seem to do a lot of analysis etc and have coaches and go training in spain or italy or wherever etc.

Nominally cat 3 ... but only because I don't do enough races to get any higher. If I look at my TT/hill climbing results I'm a very good cat 2 racer or better.

 

[black'n'yellow]

Nominally cat 3 ... but only because I don't do enough races to get any higher.

out of interest, what's been your best placing on the road this season? And what points total did you finish on? I only ask because a 'very good' 2nd cat would, in theory, only need to ride (and win, obviously) four regional C+ events (or less if national B/regional A) to move out of 3rd category.

 

[GrasB]

My only race this season was 7th in a Cat 2/3 race. I don't race in the UK & as such I don't pay any attention to points.

 

[black'n'yellow]

I'm just not clear on where the 'very good 2nd cat' bit came from, when you don't hold a 2nd cat licence and have only scored three ranking points as a 3rd. Where do you race, incidentally..?

 

[Drago]

Why do formula one cars rev four times higher than your average family saloon?
They have x amount of torques, but made four times more often to produce four times the horsepower.

Torque x revs = power.

(Enough of the car stuff).

because (at the moment) they aren't permitted variable valve timing or turbos, so there's a limit to the volumetric efficiency they can achieve. Therefore, increasing revs and chucking in more power cycles is the way forward.

Increase the strength of your F1 muscle by bolting on a turbo and peak power and torque will both be better for less revs. The current formula is limited by regulations rather than any force of physics.

As for cycling, it's not the force with which a rider can depress the pedals that is the only consideration. The Maths are a bit more complex because most fast riders will be clipped in and applying force in different directions at different points of the pedal stroke. And then there's Newtons laws of motion that coming into play when a rider is honking.

Because of my other sporting hobbie I can probably apply more force than most, but to maximise that I'd need to bolt my arriss to the seat.

One thing is for sure - big hills are a damn sight easier with big muscles than with girly ones, but what is the prime, optimum point in the middle?

 

[black'n'yellow]

One thing is for sure - big hills are a damn sight easier with big muscles than with girly ones,

No - the point is the exact opposite of that. Seriously - have you not read the thread..?

 

[Drago]

I have read the thread. I find it much easier now I'm manly and meaty than I did when I was a weakling. Simple as.

As per my earlier post, the mathematics are too simplistic, and don't take into account other variables in power transmission and are badly flawed as a consequence.

You may also recall the final part of the closing sentence of my last post, where I suggest the truth is perhaps somewhere in between the poor mathematics and my bulging quads - I mean, c'mon, have you not read the thread?

If I deploy (keeping the maths simple) 100NM of torque in the same time you apply only 80, I will go faster. If I apply 80 like you do, I'm potentially activating less muscle fibres, so it certainly won't feel so hard as my muscles are using less of their structure. Now, the energy expenditure will be the same, so someone with a better diet that mine may have an edge. Similarly, that muscle mass is just that - mass to be carried about, which requires more power. Then there is the mechanics of the power application in the pedal stroke, mechanical inefficiencies, the length of the riders bones compared to their muscle mass, even wind resistance between riders if differing sizes, so the variables to considerate very varied. Comparing just a muscle is far, far too simplistic, and leaving aside all the variables mentioned above the simple fact is a big muscle can do more 'work' in the same period of time. Come up the gym with me one evening (if you're I've 16 it'd be my pleasure to have you as a guest) and we can actually the measur of your muskets output, and do some experiments on endurance to boot.

As a slightly tongue in cheek aside, it always seems to be the week and weedy who have such a strong opinion about what muscles can't do. Those of us that have some don't seem to have these problems.

 

[T.M.H.N.E.T]

I have read the thread. I find it much easier now I'm manly and meaty than I did when I was a weakling. Simple as.

Nothing to do with erm,cycling then? And getting better at it by doing it perhaps?

As per my earlier post, the mathematics are too simplistic, and don't take into account other variables in power transmission and are badly flawed as a consequence.

Yet people still can't understand the simplest of concepts.

As a slightly tongue in cheek aside, it always seems to be the week and weedy who have such a strong opinion about what muscles can't do. Those of us that have some don't seem to have these problems.

You'll probably find that the "weak and weedy" will show you their heels on pretty much any terrain.

 

[Drago]

Ps, apologies for Mr Apples preditivadef terse.

 

[Drago]

You'll probably find that the "weak and weedy" will show you their heels on pretty much any terrain.

I've not found that person yet sonny

 

[black'n'yellow]

As a slightly tongue in cheek aside, it always seems to be the week and weedy who have such a strong opinion about what muscles can't do. Those of us that have some don't seem to have these problems.

how is it that the weak and weedy Contador can go up mountains so quickly if he doesn't have your awesome physique, Drago..??

 

[Drago]

Ah, and that's the whole point you've hit most admirably on the head Sir!

The original post was too simplistic - in terms of physics it's like trying to calculate a cars performance from its power output alone. Power is an important variable, but not the decider...

The cars weight - a heavy car will go slower for a given power output than a light one. Riders are the same.

A car with tall gearing will be slower to accelerate, slower to bring that power to bear - a rider with long bones compared to their muscle mass, such as an ectomorp, suffers the same problem.

A large slab like car will be slower all round than a smaller one with the same power due to aero properties - this is also true of cyclists.

And the list goes on.

As for my riding skills, it's pointless getting into that willy wagging arena. Ive never competed in a sporting event, so we'll never know that one. Certainly the WWWs around these parts will attest that I'm a bugger to catch up with, never mind scalp, even on my laden commuter. I've never ever done any cycle-specific fitness training in 38 years of riding, and that capacity has come from somewhere.

If anything will kneecap me, it'll be yet another variable - diet. I'm a moderately careful eater and put away a lot of proteins for the obvious reasons, but I've never paid any attention to slow-release carbs etc for cycling.

Oh, and pubs - I can't seem to do more than 30 miles without being in desperate need of a Guinness