Strava has been a great motivator for my fitness in trying to improve on climbing times. As I typically ride alone and not "racing" a friend to the top, I'm always looking for ways to shave a few seconds, keeps it fun.

so lets say on a 1.5 mile climb that basically has 3 sections - one steep 12% avg, one easy 5% grade, one medium 7% avg in that order. And lets say I have the power to go all out on one of those sections, spin one and medium on another (which is probably about accurate for me). Where should I be putting that all out effort? where do I get the most bang (time) for the buck?

When riding with friends on that same climb my strategy is usually to save that all out effort for the top but I think that has more to do with the fact we're having fun riding together and no one really usually attacks till section 2 or 3 although I have thought of applying the pressure for the get go from time to time. I understand that riding with others has so many variables that strategy can quickly get tossed out the window and you're just trying to survive at times but what about when just racing the clock????

Thanks for any advice.

Helps to know what type of power you can hold for that amount of time & where you are strong & weak. I probably wouldn't approach it like you should & you probably shouldn't approach it like the next guy/gal.
Questions like this always remind me of Carlos Sastre. He would start slow on a climb, the favorites group disappearing up ahead. Gradually he would raise his rhythm. At the top of the climb he would be back up with the group, or have passed them.

Assuming the sections are of equal length, and that you'd otherwise ride them all at the same intensity, you put in the extra effort on the section where the power increases your speed the most, which is probably the shallower section. The trick is to not overcook the steep initial section, so that you can actually lay out the extra 30w or whatever when the grade shallows.

I don't agree with chadster. A 5% grade at speed can have some air resistance losses. But the 12%? Going twice as hard will give you a full twice the speed. I don't care how strong you are. Because at your low speed, even going hard, that 12% will take, relatively, a long time. Small speed difference, while making for small distance differences, still represent real differences in total time. But going faster on the more level stretch, while making for impressive distance gains, really doesn't add up to as much time gain and if you are now going fast enough that wind resistance matters, you are throwing away effort.

The minus side is that the following sections will hurt! Especially if you have dropped your buddies and now have to not get caught.

Ben

You're not going to place on the segment unless you can hammer all three, so why worry about it? As a start, try pedaling over the tops of all three, instead of coasting. Recovering speed is as important as maintaining as much of it as you can.

There are many times differences between theory and practice...

I believe with Strava you are able to set up multiple courses, or segments, or whatever they call them. Do that, then monitor time in each segment. As an example, you may find that hard exertion in section A slows the moderate and easy exertion in the later sections (since you will be more tired) or you may find the difference is minimal and/or is eclipsed by the better time in section A.

I know setting up segments on the tools like MapMyRide or Strava are not necessarily accurate (at least not easily) in setting up segments, but if you can get close to the dividing line between the various slopes, I would suggest using the tool for all it is worth.

Go hardest on the 12% section, where the speed gains from more power are closer to linear (the force of gravity acting on you is a constant so power to overcome it is proportional to speed, while aerodynamic drag increases with the square of velocity and power with speed its cube) and you're spending a disproportionate amount of time on.

Spin easy on the middle section. That'll have the least impact on your overall time and let you recover a bit for the last section.

Go medium on the last.

Hmm, well, I'm not so good at the maths, but using the formulas I found here (Ultra Cycling » Cycling Power Calculations), it looks like the following should be true:

Overcoming wind and air resistance to travel 12mph on flat ground, no wind, would require 23.5w.

Assuming about 189lb combined rider and bike weight (86kg) and exclusive of wind/air resistance:

12% grade @ 5mph = 225w
12% grade @ 7mph = 315w
5% grade @ 10mph = 188w
5% grade @ 12mph = 225w

So, if you add in the 23w for wind/air resistance to the 5% @ 12mph, that's about 250w.

It looks to me, then, that there's about 2x speed gain for the same watt output on a 5% grade than a 12% grade. Is that what you see there, too?

If your FTP is 250w, you can hold that for either around 6mph on the 12%, or get 12mph on the 5%.

Again, if the segments are of equal length, I'd throttle back on the 12% for an easier high-tempo output, kick up the RPMs and watts to threshold on the 5%, and drop back to tempo on the 7% for the quickest hill climb effort.

There just doesn't seem to be much speed to gain on the 12% for rather massive increases in power output. Or am I looking at this wrongly?

Great stuff...thanks and yes, the segments are fairly equal in length. Most of my best times have been doing just as you described but my PR came from hitting the first section hard, resting on the 2nd, and hitting the last section hard again. I know, not as I described in terms of my available output and why a PR but good info on how to generally do the ride for best results.

Spin and stay below redline, works for me on the mt bike.

That's what I do for my training. Once I got a premium strava account I was able to monitor HR, power, etc. The first thing I did was setup “segments” of all the hills on my local route and broke down my local loop into 4 major parts. My local loop is about 32 miles with 2500’ overall. The key though is the start of the loop has 3 good climbs about 1200’ in about 7 miles. Initially I would hammer the easy portion of the climb because I was fresh and had lots of power then I would quickly die on the steep hill and just have to pull over. By setting up segments of each hill I can see how much power and speed I was putting on the 5% grade before I got to the 10% grade. Sadly I was just going too fast for my own good. I learned that setting a 8mph pace on the first part was fast enough without killing me on the next few hills. As I rode the loop more and more I would move up the first part of the loop from 8mph to 10 and the 2[SUP]nd[/SUP] part of the loop from 6-7 and slowly increase my speed and power. Since I almost always ride alone on this loop I know what time I should have for each overall segment of the loop. Knowing this keeps me motivated to keep my pace even when I don’t feel like riding. I’ve managed to consistently increase my time on each climb, segment and the overall loop just about every ride.

Sure, it's all going to depend on how much effort you need to put into the climb, your overall fitness, and the everyday things like weather, nutrition, and simply how you're feeling on any given day. Also, without a power meter, it's very hard to know what you're actually doing, as perceived effort is vagarious.

Personally, I'd go medium on the 12%, rest/recover on the 5%, and sprint the 7%.

If I sprinted the 12%, I'd be toast the rest of the way up.

Yes. As 79pmooney and others have mentioned, you should be going hardest on the steepest section. It's the same principle that applies when doing a hilly TT. It's fastest to go a little harder on the hills. How much harder, you'll need to experiment based on the length of the hlil.

Assuming the hill is equally divided into 12, 5 and 7% sections, and you can climb for that time at 1000 VAM, it should take a little under 12min with about half that time spent on the first steep section. 10% extra power on the first section would shave about .6 min or 36 Seconds. 10% extra power on the 5% section wouldn't save as much time as the time spent on the section is less and more energy gets wasted due to aero losses.

The other factor is gearing, I'd end up standing and going quite a bit harder on the 12% section just because I don't have low enough gears to spin up a hill like that.

Yes. Yes.

(No insult intended.)

Ok, I think I get it; our numbers align, but I was neglecting the "time spent per section" factor, and was just looking at speed. So yeah, it looks like my 86kg rider/bike combo with a VAM of 1000 would save the 30-some seconds on the 12% (at 250-260w vs. 228w) and only about 15 seconds on the 5% grade by bumping up from 228w to 250w.

Bike Calculator makes the modeling easy, but thanks for pointing out where I was going wrong.

So its hammer the first section, recover on second and then give it a go (higher tempo) on the 3rd then? All things being equal (which they never are)...

Thanks...

On physics I agree with those saying work the steepest section harder.

On a biology point and especially as it relates to getting a better time next week and next month I say work your worst section the hardest.