Pro compact 52x36

bernithebiker

Imposter wrote:

bernithebiker wrote:

You are historically fixated with the idea that cycling uses less force than just about anything else a human can do. I disagree.

Good - so do I.. That's an absurd strawman argument, not to mention something I have never said.

Er, these are your words;

"My point is, the forces are still significantly less than those used when walking, running, climbing stairs, etc."

bernithebiker wrote:

When a powerful sprinter is going for the line in a big gear and putting over 1000W through the pedals, sorry, but that's a lot of force right there. Force that can snap chains, flex wheels and bend frames.
Similarly, if I was to try and climb Sa Calobra in 50-11, I really don't think it would do me, my legs or my joints much good.
Cycling IS low force, low impact if you take it easy and spin, which is why it is prescribed over running.

Imposter wrote:

Doesn't sound like you understand the difference between power and force, but let's stick to the discussion in hand. It is obviously possible for cyclists to get knee problems, just like anyone else - from things like over-use, poor fit, things like that. But the specific issue of high-gear work promoting knee problems in an otherwise healthy knee (or knees) is not proven as far as I'm aware. Steve Hogg has a good page on knee problems here:

https://www.stevehoggbikefitting.com/bi ... knee-pain/

No mention of pulling high hears up hills though...

Well I have a degree in mechanical engineering so I probably know more about force and power than you do. I mentioned 1000W simply to illustrate the very high powers that sprinters can produce. Their cadence will be high too, but not always, and this will result in very high forces through the legs.

You seem to think our legs are immune to any force going through them. Imagine trying to leg press double what you normally could. The strain on your legs and joints would be enormous. Grinding a big gear up a climb and pushing as hard as you can is not going to do your joints any favours, long-term.

drlodge

dennisn wrote:

I'm not talking about you or me or a car. I'm talking about the amount of work it takes to move an object of a certain weight(you and a bike) a certain height(vertical drop). That has nothing to do with "efficiency". No matter what "efficiency" you pedal with or the car motor runs has any or zero effect on the amount of work that must be done to move you and bike or car to the top of the hill.

Technically that's true. However lower rpm requires greater torque and if you exceed the torque output of the legs/engine etc then it goes kaput. High torque is never good - it strains the legs, strains the internal combustion engine and will lead to premature wear/fatigue.

imposter2.0

bernithebiker wrote:

Er, these are your words;

"My point is, the forces are still significantly less than those used when walking, running, climbing stairs, etc."

Correct - and the words "cycling uses less force than just about anything else a human can do" are remarkably absent.

bernithebiker wrote:

Well I have a degree in mechanical engineering so I probably know more about force and power than you do.

Oh dear. First you gave us a strawman, and now an embarrassing 'appeal to authority'.

bernithebiker wrote:

You seem to think our legs are immune to any force going through them.

Seriously?

bernithebiker wrote:

Imagine trying to leg press double what you normally could. The strain on your legs and joints would be enormous. Grinding a big gear up a climb and pushing as hard as you can is not going to do your joints any favours, long-term.

Berni - I think you need to put away your degree certificate and calm down. I've never argued that pushing harder on the pedals does not result in an increased force through the joints. My only argument - which you have either missed, or are resolutely ignoring - is that those increased forces would not, in themselves, be enough to cause knee problems in an otherwise healthy human knee (or knees).

dennisn

drlodge wrote:

dennisn wrote:

I'm not talking about you or me or a car. I'm talking about the amount of work it takes to move an object of a certain weight(you and a bike) a certain height(vertical drop). That has nothing to do with "efficiency". No matter what "efficiency" you pedal with or the car motor runs has any or zero effect on the amount of work that must be done to move you and bike or car to the top of the hill.

Technically that's true. However lower rpm requires greater torque and if you exceed the torque output of the legs/engine etc then it goes kaput. High torque is never good - it strains the legs, strains the internal combustion engine and will lead to premature wear/fatigue.

Not talking torque or strain or rpm's. Whether your body, legs lungs, etc. are efficient or not makes no difference in how much work you must do to raise you and your bike up that hill. Most likely, in climbing that hill you will put out more work than is necessary to get you there. This is because your body and mind are not perfect and you will expend valuable work in the form of poor climbing form, poor efficiency, flailing the bike around, uncontrolled breathing, and possibly even poor mental attitude as the climb drags on.

dennisn

Imposter wrote:

bernithebiker wrote:

Er, these are your words;

"My point is, the forces are still significantly less than those used when walking, running, climbing stairs, etc."

Correct - and the words "cycling uses less force than just about anything else a human can do" are remarkably absent.

bernithebiker wrote:

Well I have a degree in mechanical engineering so I probably know more about force and power than you do.

Oh dear. First you gave us a strawman, and now an embarrassing 'appeal to authority'.

bernithebiker wrote:

You seem to think our legs are immune to any force going through them.

Seriously?

bernithebiker wrote:

Imagine trying to leg press double what you normally could. The strain on your legs and joints would be enormous. Grinding a big gear up a climb and pushing as hard as you can is not going to do your joints any favours, long-term.

Berni - I think you need to put away your degree certificate and calm down. I've never argued that pushing harder on the pedals does not result in an increased force through the joints. My only argument - which you have either missed, or are resolutely ignoring - is that those increased forces would not, in themselves, be enough to cause knee problems in an otherwise healthy human knee (or knees).

Berni - I think you're arguing with someone to who can't imagine that there is ANYTHING bad about cycling. To him it's perfect and with no faults. Sort of a "you don't need anything more in life than to ride" type of person. Seems to be more than a few of them on this forum.

imposter2.0

dennisn wrote:

Berni - I think you're arguing with someone to who can't imagine that there is ANYTHING bad about cycling. To him it's perfect and with no faults. Sort of a "you don't need anything more in life than to ride" type of person. Seems to be more than a few of them on this forum.

Never seen so many strawmen in one place. If only I had a lighter. Another one who likes to attack the poster, not the content.

drlodge

I forget what the argument is about anyway...debating 34x50 vs 36x52 is pointless as gearing is all about ratios, and it all depends on what's running on the back. Oh and other factors like terrain, fitness etc etc. Aesthetics seems a rather pointless reason to go for one or the other.

Gearing is, afterall, a torque converter. torque x rpm = power. Lower one, increase the other, power stays the same.

singleton

amrushton wrote:

48/36 with an 11-28 or 12-30?

bernithebiker wrote:

50/36 with 11-28

I don't understand either of those combinations.

If the standard setups are 52/36 or 50/34 why would you go for a 48/36 or a 50/36?

drlodge

Singleton wrote:

amrushton wrote:

48/36 with an 11-28 or 12-30?

bernithebiker wrote:

50/36 with 11-28

I don't understand either of those combinations.

If the standard setups are 52/36 or 50/34 why would you go for a 48/36 or a 50/36?

48/36 is more of a CX setup, not uncommon.

imposter2.0

The nice thing about gearing is that you can tailor it almost 100% to match the type of rider you are - and the type of riding you do.

Suggesting gearing to people is a bit like telling someone what size trousers they ought to wear...

bernithebiker

Imposter wrote:

bernithebiker wrote:

Er, these are your words;

"My point is, the forces are still significantly less than those used when walking, running, climbing stairs, etc."

Correct - and the words "cycling uses less force than just about anything else a human can do" are remarkably absent.

Well I would say that walking, running, etc. covers most 'normal things a human can do'.

bernithebiker wrote:

Well I have a degree in mechanical engineering so I probably know more about force and power than you do.

Imposter wrote:

Oh dear. First you gave us a strawman, and now an embarrassing 'appeal to authority'.

Oh dear indeed. You were the one that suggested I didn't understand power, so presumably I need to prove that in fact, I do.

bernithebiker wrote:

You seem to think our legs are immune to any force going through them.

Imposter wrote:

Seriously?

Yes!! You seem to think that high forces in legs in cycling couldn't possibly do any harm.

bernithebiker wrote:

Imagine trying to leg press double what you normally could. The strain on your legs and joints would be enormous. Grinding a big gear up a climb and pushing as hard as you can is not going to do your joints any favours, long-term.

Imposter wrote:

Berni - I think you need to put away your degree certificate and calm down. I've never argued that pushing harder on the pedals does not result in an increased force through the joints. My only argument - which you have either missed, or are resolutely ignoring - is that those increased forces would not, in themselves, be enough to cause knee problems in an otherwise healthy human knee (or knees).

Well we disagree then. I ride with many excellent ex-racers in their 50's and 60's who are all of the same opinion; high force cycling does not do your joints any good long term.

imposter2.0

bernithebiker wrote:

Well we disagree then. I ride with many excellent ex-racers in their 50's and 60's who are all of the same opinion; high force cycling does not do your joints any good long term.

That, I'm afraid, is yet another 'appeal to authority'. I am also an ex-racer in my 50s (the word 'excellent' is very subjective, so we'll gloss over that). My knees are fine. Your anecdote suggests one thing, mine suggests another. Which is why I am suggesting we discard the anecdotes and look for actual evidence instead. Surprised you can't comprehend that, what with you having an engineering degree 'n all...

drlodge

Well it seems we can't agree that cycling has any effect at all on knee joints. Does it?

I can't imagine low force cycling will be detrimental to the knees, which just leaves high force cycling...

The statement

high force cycling does not do your joints any good long term

seems like common sense. That's not to say everyone who cycles using high force at some point will suffer knee problems, but it will increase the risk. And the more you do it, the higher the risk. Its like smoking and lung disease. Not all smokers get it, and some non-smokers get it anyway. But those who smoke are more likely to get it.

I'm not sure you can prove the point either way without some scientific trail with a large enough sample.

imposter2.0

drlodge wrote:

That's not to say everyone who cycles using high force at some point will suffer knee problems, but it will increase the risk. And the more you do it, the higher the risk.

Sorry, but there you go again. You have no evidence whatsoever for saying that. You have no idea whether it will increase risk or not, because there is no evidence for it one way or the other. If only you would stop talking in absolutes, I would leave you alone..

pinno

I think tyre pressures are critical and nicely placed decals that are lacquered over (if you can find any) and extra drill holes in your helmet for ventilation and an aluminium hat to ward off aliens reduces all sorts of stress and sex before marriage needs to be made compulsory - just in case...

pblakeney

Pinno wrote:

I think tyre pressures are critical and nicely placed decals that are lacquered over (if you can find any) and extra drill holes in your helmet for ventilation and an aluminium hat to ward off aliens reduces all sorts of stress and sex before marriage needs to be made compulsory - just in case...

But only if you upgrade from SPD first.

bernithebiker

Imposter, this is from Sheldon Brown, you know, the guy that knows naff all about cycling;

"Knees

Cycling, done properly, is much less stressful to the knees than many other aerobic activities, since there's no impact involved. Nevertheless, knee injuries do occur, usually as a result of poor technique or position.

Gear Selection

A principal cause of knee problems is over-stress as the result of using too high a gear. For more on this, see my article on Gear Shifting."

I bet he doesn't understand Power either, right?

imposter2.0

FFS. I give you Steve Hogg - you give me Sheldon Brown. You are either desperate, or deluded. I don't want to trash Sheldon, but let's just say it's an utterly absurd comparison and leave it at that.

bernithebiker

Imposter wrote:

FFS. I give you Steve Hogg - you give me Sheldon Brown. You are either desperate, or deluded. I don't want to trash Sheldon, but let's just say it's an utterly absurd comparison and leave it at that.

You just hate being wrong.....

darkhairedlord

Imposter wrote:

FFS. I give you Steve Hogg - you give me Sheldon Brown. You are either desperate, or deluded. I don't want to trash Sheldon, but let's just say it's an utterly absurd comparison and leave it at that.

I'm not saying anything either way but, Steve Hogg? Now there's a man in another universe, right out there with the thetans.

imposter2.0

Don't get me wrong - I just used the Steve Hogg link as a reference back when we were talking about some of the origins of knee pain. By the same token, I would not be using dear old Sheldon as a reference either.

All I've ever said is that there is no particular evidence that pushing a high gear leads to knee problems. Counter arguments like "surely it has to" and "my excellent ex-pro mate said it did" don't really cut it...

bernithebiker

Imposter wrote:

Don't get me wrong - I just used the Steve Hogg link as a reference back when we were talking about some of the origins of knee pain. By the same token, I would not be using dear old Sheldon as a reference either.

All I've ever said is that there is no particular evidence that pushing a high gear leads to knee problems. Counter arguments like "surely it has to" and "my excellent ex-pro mate said it did" don't really cut it...

And there is no particular evidence that pushing a high gear does NOT lead to knee problems either.....cuts both ways, right?

imposter2.0

Congrats Bernie - you have successfully reached gold standard 5* absurdity. I've used that word a lot in this thread. I'm getting out now, before you are consumed by dark matter...because there's no evidence it doesn't exist...

bernithebiker

Imposter wrote:

Congrats Bernie - you have successfully reached gold standard 5* absurdity. I've used that word a lot in this thread. I'm getting out now, before you are consumed by dark matter...because there's no evidence it doesn't exist...

You're weird.

Matthewfalle

I've got a "pro" compact (I prefer to call it a "lovely crank bought in the sales compact") on my holiday bike. I can't tell any difference between the 52x36 and 53x39 on the rest of the bikes, apart from the hundreds of pounds I saved when buying it because it was in the sales.

Hope that doesn't muddy the waters.

pinno

Matthewfalle wrote:

I've got a "pro" compact (I prefer to call it a "lovely crank bought in the sales compact") on my holiday bike. I can't tell any difference between the 52x36 and 53x39 on the rest of the bikes, apart from the hundreds of pounds I saved when buying it because it was in the sales.

Liar.

Matthewfalle

No, its true. Its a carbon one I got for about £50 down from something silly like £250 because it was last years colours. I'll take a picture of it in July when I go over.

I honestly can't tell any difference at all.

Its like when people say that they can feel the difference between a 175mm crank and a 172.5mm crank on their really fast Sunday chain gang with all their really fast 'n' cool bicycle club friends. No difference at all.

pblakeney

Nonsense.
There is a clear and obvious 2.5mm difference.

pinno

PBlakeney wrote:

Nonsense.
There is a clear and obvious 2.5mm difference.

Per crank. That means a 5mm difference in diameter which is life threatening especially if you put them on a CF frame and pedal in the rain; lethal. That's why the combination of discs and Barbour's waterproofing wax is essential.

bendertherobot

I've gone down to a compact because a) I am pathetic and b) the Spider like rings for the Cannondale Si were only available cheaply in 50 / 34

So, basically, set of FSA pro compact rings in the classifieds if anyone hard wants them.