During a long climb, what is speed when I should just sit up and spin.
I get up around 13mph, not sure if it is right.
To me it’s more of a “feel”. I want to say at 10 mph or less. But, I’m no expert. I will say that was one area I improved on this season. I stayed aero 98 to 99% of my races. Bike fit has a lot to do with it.
This season is a run focus. I’m coming back after a 5 year layoff. Swim was above average for me, bike was FOP, run was mid. I didn’t really do any speed training for run.
I usually get up on the base bar around that same speed or maybe a little slower. A lot depends on the grade and length of the climb as well. If it’s just a short and punchy hill, I’ll try and stay tucked in. If it’s a medium to long climb, I’ll get out of aero and even stand up and pedal some to give my taint and back a break.
Don’t forget that it’s your airspeed that’s important. So if you’re riding into a 15mph headwind up the hill you ought to stay aero right down to walking speed. Conversely if you’ve got a solid tailwind, sitting up earlier won’t hurt you and if it’s a strong enough tailwind sitting up will help sail you up the hill.
YMMV,
Hugh
I probably sit up around 15-16 MPH. It depends a lot on the length of the climb and my power output.
I’ll have to hunt this down, but I know one version came from specialized win tunnel videos.
Going slowly, on a flat road, you actually gain more time staying in aero, then going faster (as a percent of your overall time). At this point, on a flat road, gravity accounts for almost 0 percent of the force slowing us down, and air resistance counts for nearly 100%
That said, most of us slow down because we are going up a hill. As the hill gets steeper, the percentage of forces your are overcoming that are coming from the air vs gravity switches… By, 2-3 percent grade, gravity is the primary force in front of your speed. Staying in aero will still drop your aero drag by roughly the same number of grams on a hill… It just matters way less because what you need is power to get up the hill.
2-3% grade is nothing. That number can’t be right
I believe the number was 6% for amateurs and even higher for pros since they ride up hills quicker then we do. Thought this came from a test done by Cervelo, but at least those were the numbers. 2-3% grade indeed is nothing. Your speed should still be high enough there that aero outweighs weight.
There is no easy right answer to that.
In still air it entirely depends whether you can produce more power by sitting up. If you can’t, it’ll never be faster to sit up as drag will increase. However, if you can sustainably produce more power by sitting up, then there will be a combination of slope, and speed when you would be better to sit up. Of course it’s not this simple either. This assumes that any extra power from sitting up doesn’t impact your performance later in the race, or that an accumulation of discomfort from staying tucked could impact you later, especially on a steep slope where the tuck position may not be as ergonomic as usual. Furthermore the above assumes still air; and as another poster already covered - wind should factor strongly in your decision:
Don’t forget that it’s your airspeed that’s important. So if you’re riding into a 15mph headwind up the hill you ought to stay aero right down to walking speed. Conversely if you’ve got a solid tailwind, sitting up earlier won’t hurt you and if it’s a strong enough tailwind sitting up will help sail you up the hill…
Even the above is a drastic simplification that ignores things like rolling resistance (impacted by weight distribution, shock absorption etc which vary with rider position).
So, no easy answer.
My experiences are when I am rolling on flat ground, no wind, under 17 mph I will normally come out of the bars.
Under those conditions I’m likely pedaling 100-120 watts or less than half my FTP.
If I’m going uphill it’ll probably be the same.
If I’m going against the wind I’ll probably go a little slower.
These speeds are purely anecdotal.
During a long climb, what is speed when I should just sit up and spin.
I get up around 13mph, not sure if it is right.
Long climb, I’m probably wrong but I come up at that speed too and even grab onto the arm pads a bit. I saw Sam Long do the same thing so I don’t feel bad, I just take it as a time to get massive amounts of air and even push sone higher power. I can stay down but this feels right. Just my 2cents
During a long climb, what is speed when I should just sit up and spin.
I get up around 13mph, not sure if it is right.
Let’s pretend your CDA in aero is 0.25 and sitting up, 0.35
At 13mph = 21km/h = 5.78 m/s
Let’s pretend air density is 1.18, no wind.
Power to overcome aero drag will be 0.5 * 1.18 * 0.25 * 5.78^3 , therefor in aero = 28.48watts
Out of aero 0.5 * 1.18 * 0.35 * 5.78^3 = 39.88watts
So it’s costing you 11watts. Chances are you can put down more than 11extra watts out of aero and/or changing position will just be good for the rest of your race
I put the formulas so you could play with them yourself
All Aero all the time, even up hill. I’ve learned that at any speed you always lose it when you get up. That isn’t to say I don’t get out of aero, I do to shift around quite a bit lol. But not for more than a minute.
Very interesting and it’s not too different from the calcs that the guys at Endurance Innovation did on one of their latest podcasts. They were getting to 18-22 kph as the threshold for most age groupers with an OK CDA.
EI is a great podcast. They typically have really good looking guests. (Joke. I did two with them)
On the climbs, when sitting up, it’s time to drink, eat…do all the stuff that isn’t ideal in aero.
Out of curiosity (and for lack of physics smartness), how would you include the wind component into the formula? Is it a variation on the speed or can you have it as another factor in the equation?
The point when your speed does not change going from aero positions to the base bar. If you notice yourself slowing down when you get out of aero, then you should have stayed in aero.
Out of curiosity (and for lack of physics smartness), how would you include the wind component into the formula? Is it a variation on the speed or can you have it as another factor in the equation?
In the above I did.
Power to overcome aero drag will be 0.5 * 1.18 * 0.25 * 5.78^3 , therefor in aero = 28.48watts
In fact it 0.5 * 1.18 * airSpeed^2 * groundSpeed. When airSpeed = groundSpeed (no wind) it becomes groundSpeed^3.
So if there is a 1m/s (3.6km/h) headwind, it would be 0.5 * 1.18 * 0.25 * 6.78^2 * 5.78 = 39watts
And 0.5 * 1.18 * 0.35 * 6.78^2 * 5.78 = 54watts, so a 15watt difference
During a long climb, what is speed when I should just sit up and spin.
I get up around 13mph, not sure if it is right.
Let’s pretend your CDA in aero is 0.25 and sitting up, 0.35
At 13mph = 21km/h = 5.78 m/s
Let’s pretend air density is 1.18, no wind.
Power to overcome aero drag will be 0.5 * 1.18 * 0.25 * 5.78^3 , therefor in aero = 28.48watts
Out of aero 0.5 * 1.18 * 0.35 * 5.78^3 = 39.88watts
So it’s costing you 11watts. Chances are you can put down more than 11extra watts out of aero and/or changing position will just be good for the rest of your race
I put the formulas so you could play with them yourself
I agree with this.
The “average joe” makes a lot less power in aero. Like, probably more than 20w less. Just do the math on the gradient of the hill and your estimated speed and you can go from there.
Probably most relevant to middle of pack age group triathletes versus strong time trial racing. The average speed would be a lot less and getting into that gray area when going uphill. Gotta think a lot of folks are targeting less than 200w for a full IM and 200w for a not skinny person isn’t super fast up even 4%.
In a TT I’m almost never out of aero. I’ll take some pretty sharp corners in it even if I’ve practiced the course before. Simply because even uphill due to the local area here that hills are short and the momentum from descending at over 40mph starting up a hill with that I may never get under 20mph.
During a long climb, what is speed when I should just sit up and spin.
I get up around 13mph, not sure if it is right.
The answer depends on how much power you individually gain by sitting up. If you gain nothing (some people basically gain nothing) then you should just stay in the aero bars all the time. If you gain a huge amount then you should sit up even at faster speeds, like 15mph and sometimes even faster. The same goes for standing up out of the saddle.