Question re cadence/gearing/hills
nasahapley
Posts: 717
I'm hoping some of you sports science/coaching types out there will be able to resolve a query regarding the above; I've asked this of a few cyclists but I'm still a bit confused -
It seems to be generally accepted that a cadence of around 90, give or take, is optimal for almost everyone, and I'm not going to quibble with that. What I don't understand is why often the very same people who say my cadence should be a bit higher (it's usually only about 80), also advocate grinding up hills in what I would think of as pretty high gears for climbing. For instance, I've heard it said loads of times that 34-25 should get you up anything, and I'm sure it would, but grinding even this gear at a lowly 60rpm up a 1-in-5 (steep but not unusual), would require a power output of over 6 watts/kilo - which is (correct me if I'm wrong!) more than most of us could sustain for long. I would guess a reasonably fit cyclist would be looking at a sustainable cadence of more like 40 in such circumstances, which seems very low indeed.
I guess the question is why is a cadence of 90 'right' for the flat, but much lower cadences 'right' for climbing? And if pushing big gears up the hills builds fitness (as I'm told it does), then why don't we all mash 53-11s on the flat for the same reason?
All answers gratefully received!
N
It seems to be generally accepted that a cadence of around 90, give or take, is optimal for almost everyone, and I'm not going to quibble with that. What I don't understand is why often the very same people who say my cadence should be a bit higher (it's usually only about 80), also advocate grinding up hills in what I would think of as pretty high gears for climbing. For instance, I've heard it said loads of times that 34-25 should get you up anything, and I'm sure it would, but grinding even this gear at a lowly 60rpm up a 1-in-5 (steep but not unusual), would require a power output of over 6 watts/kilo - which is (correct me if I'm wrong!) more than most of us could sustain for long. I would guess a reasonably fit cyclist would be looking at a sustainable cadence of more like 40 in such circumstances, which seems very low indeed.
I guess the question is why is a cadence of 90 'right' for the flat, but much lower cadences 'right' for climbing? And if pushing big gears up the hills builds fitness (as I'm told it does), then why don't we all mash 53-11s on the flat for the same reason?
All answers gratefully received!
N
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Comments
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To start with people saying that they can do a certain thing and actually doing it could be
two different things. If you claimed that you climbed a 20 percent grade hill that was 20 miles long in an hour someone will come along and better that by 10 more percent, 30
more miles, and only take half an hour. So, can you get up "anything" with a 34-25?
I'm sure there are more than a few out there who can. Can all of us do it? Hell no, that's
why they make triples. I have a compact and run a 50-34 with an 11-21 on the flatlands where I live. In the mountains I switch out to a 50-33 with a 12-27. I find myself still
"grinding" it out a lot on long climbs. I don't seem to be able "spin" up hills all that well and
I think this is true with most people. Watching people climbing in the Rockies, there cadences mostly slow down a good bit from their flat section riding.
Dennis Noward0 -
nasahapley wrote:For instance, I've heard it said loads of times that 34-25 should get you up anything, and I'm sure it would, but grinding even this gear at a lowly 60rpm up a 1-in-5 (steep but not unusual), would require a power output of over 6 watts/kilo - which is (correct me if I'm wrong!) more than most of us could sustain for long. I would guess a reasonably fit cyclist would be looking at a sustainable cadence of more like 40 in such circumstances, which seems very low indeed.
N
Personally, I'd take most such claims with a Pinch of Salt
People's cadence varies throughout the course of a hill and on the steeper sections typically drops away considerably - that effect is accentuated when riding hills on tired legs (ie 60-80 + miles). 0 -
I suspect that grinding up hills with low cadence over-stresses joints and could lead to arthritis later and injuries now. For me I prefer to have low enough gears available so that for at least slopes up to say 15% I can spin with low pressure. Slopes steeper than this are sufficiently short/rare that I will just grind and endure it! I wonder if an element of pride compels some riders to avoid having gears that allow them to keep the cadence up?0
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You're in the right ball park with your maths.nasahapley wrote:For instance, I've heard it said loads of times that 34-25 should get you up anything, and I'm sure it would, but grinding even this gear at a lowly 60rpm up a 1-in-5 (steep but not unusual), would require a power output of over 6 watts/kilo - which is (correct me if I'm wrong!) more than most of us could sustain for long.
Depends on a few factors such as weight of bike and other equipment. An 80kg bike + rider doing 60rpm on 2096mm tyres in a 34x25 would, on a reasonable road with half decent tyres, need put out at the crank ~ 460-465watts or 5.8W/kg for bike + rider or 6.6 W/kg for rider mass alone.
That is a power output that a fit cat 3 cyclist could sustain for maybe 2-3 minutes or so.
Indeed it is. and yes 40rpm would be a more manageable power of ~ 305-310W (4.4 W/kg rider mass) on your theoretical climb. But not if it's a long climb for an average cycist.nasahapley wrote:I would guess a reasonably fit cyclist would be looking at a sustainable cadence of more like 40 in such circumstances, which seems very low indeed.
Typically we ride lower cadences uphill, simply because we don't a large enough range of gears on our bike to do anything else.nasahapley wrote:I guess the question is why is a cadence of 90 'right' for the flat, but much lower cadences 'right' for climbing? And if pushing big gears up the hills builds fitness (as I'm told it does), then why don't we all mash 53-11s on the flat for the same reason?
On your example hill, to ride at your suggested more sustainable speed (power), then you would require a 23 tooth chainring and a 26 tooth cog to get to 60rpm. I don't see many road bikes with gearing that low.
Large gear (low cadence) riding does no more for your fitness than normal gear riding (at same speed/power). It's how much power you are putting out that matters.0 -
About the same stress as walking up stairs with a couple of bags of shopping.normanp wrote:I suspect that grinding up hills with low cadence over-stresses joints ...0 -
Alex_Simmons/RST wrote:
About the same stress as walking up stairs with a couple of bags of shopping.normanp wrote:I suspect that grinding up hills with low cadence over-stresses joints ...
A lot of stairs if the hill is an alpine col....
And with heavy shopping bags if you're built like me...0 -
IanTrcp wrote:Alex_Simmons/RST wrote:
About the same stress as walking up stairs with a couple of bags of shopping.normanp wrote:I suspect that grinding up hills with low cadence over-stresses joints ...
A lot of stairs if the hill is an alpine col....
And with heavy shopping bags if you're built like me...
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