[Gnarly 928]

Ok, here is a question for you Timed Event specialists. I've been racing mass start races mostly my whole racing 'career'. I just recently started entering more TTs and hillclimbs. I've finally trained my weight down to where I can now climb OK. I also got pretty soundly spanked last fall in a TT, my first TT in a long while. Time to work on those, too.
So, it seems to me that when you are racing against the clock, you should try to use your most intense efforts when they will save the most time. Been trying to figure it all out during my long hours in the saddle, and I've come up with some ideas (with some input from elsewhere, sure..)
A riding partner of mine is friends with some of the RAM guys of old. He says Pete Pensaries (sp?) told him how he used to make the best times across the US...Pete told him you 'gain' the most time right over the top of the climbs...Pete says if you really keep hammering as you crest a hill and on down the other side, you make big time savings because you increase your speed very quickly and can carry a higher bike speed for a longer distance...Probably not explaining that the best way..but..
So, applying that idea (sort of..) to a time trial/hill climb, wouldn't it be true that when you do go "red-zone" during the event, you should save it for the places where you'll increase your speed by the largest amount?
Using fictional numbers... Like this..say on a 9% section of the climb you can just sustain say 14mph without exceeding your redline..You can bump that up to about 16 or so for maybe 2 minutes, but then you gotta recover, clear out your legs, so back to 14mph you go.. But on this theorhetic hillclimb course, there are a few "flat spots" down to say 6% grade..If you saved your "over the redline" efforts for those spots and hammered there, wouldn't you make better time? You could kick it up from 14mph to maybe 20..Of course, when the hill got steep again or you load up your legs, you'd have to notch back, just like if you hammered on a 12% pitch to keep your speed at 14 mph, but would you not be further ahead? (by saving your max effort for a section where your resultant speed increase would be much greater?)
Now, most riders I know and ride with seem to save their biggest efforts for the steepest climbs, right? It is just natural, especially for us who race against other people, more than we race against the clocks...We all try to put the hurt on other riders by hammering up a wall. We usually sit up breifly at the top of a climb, too, right? And we seem to like to recover some when the gradient gets gentler...Am I wrong in thinking that all those behaviors are counter-productive in a race against the clock? Should I work on developing new habits? Hammer the hardest when the riding is easiest for better times? Get into the big chain ring for the apron of the climb, like? Haul a** through the dips, and recover on the steepest pitches.. What say you all?
Don Hanson

 

[gray8110]

Honestly, in the most direct sense, you are overthinking things here. The key to performing well in most TT's & hillclimbs is steady effort. The ideal TT effort is riding at the maximum intensity you can maintain for the duration - going harder than that for very long will eventually slow you down more than you gained with that extra effort. A lot of what you say is true, specifically upping the effort at the crest of a climb to maximize speed and recover from that effort without losing speed on the descent - however those opportunities are short and overdoing it on a steep section will catch up with you.

As far as new habits - if you want to improve in TT's, working on hammering the easy parts and recovering on the hard parts (or vice-versa) will not be a benefit. Learning how hard you can ride for the duration of an event and training to that limiter will be what improves your time trialing the most. There are moments where you can gain time by making a short effort and recovering - as I said the crest of a hill is a perfect example, but 95% of a time trial is steady pacing.

 

[wavylines]

You can geek out on this from BikeTechReview (i.e. Kraig Willet): http://www.biketechreview.com/power/supercomputers.htm

Short answer: manage your effort so that the steeper the section you're on, the harder you work. The steeper the road, the more of your effort goes into fighting gravity rather than air resistance. Fighting gravity gives you a 1:1 effort:speed ration, so if you work 10% harder, you go 10% faster. But air resistance is (roughly) a 3:1 ratio, so you have to work 30% harder to go 10% faster. In other words, you get more for your effort the steeper the road, so work hardest when it's steepest.

That's the math, though gray's probably right that it's overthinking. Knowing this hasn't helped me in any TT's, I don't think, but I find the physics interesting.

 

[Gnarly 928]

more..

So far, from two posts, we have two diametrecially opposed veiws. Sort of.
It is certainly a fact that defining your limit and using that in training plus riding "at" that limit for the duration of the event will give you your best times. But we all know that we can exceed our 'limit' for breif interludes without totally 'blowing up'. Think back to almost any crit you've ever raced...and recall the pack behavior..
"Over-thinking" or "geeking-out"? Perhaps. But you have to think of something while you are out there daily turning those cranks. And what better subject for thinking, while you are training for racing, than how to improve your racing?
OK, agreed, there aren't going to be any 'magic minutes' to be found in small details like this question, but once we all train up to our fullest potential, the details are all that are left, really. Look over some of your past finishing results, like I have done. The time margins are very very small, sometimes...If there are any unfound seconds 'laying around' on the course, seconds I can find by learning, I want em. If I learn I could gain say 5 seconds in an hour TT or 15 seconds in a hillclimb by slightly different riding behavior, why not? Should I just keep on with the "try harder"? "Train more?"...been there, doing that. I think it's also smart to use my brain to try to figure out where and how I can improve by riding smarter. Hence, the original question. And, "the physics" is interesting, too. Some engineer out there should be able to speak to the physics...
Don Hanson

 

[asgelle]

So far, from two posts, we have two diametrecially opposed veiws. Sort of.

Yes, but you'll notice one point of view includes reference to an article with both calculated and real-world data to back up that position. The other states an opinion with absolutely nothing to back it up. You can draw your own conclusions, but the consensus among those who have looked into it through modeling and field test is that a variable pacing strategy going harder on the slower parts (uphill, into the wind, etc.) is faster than a steady effort.

 

[Gnarly 928]

Interesting article referenced here..

That is the kinda experiment that could be helpful. Interesting to see that varying the amount of power input seems to make almost half a minute's difference, using this fellow's math. Interesting, too is his conclusion that 'going out and riding a lot' is going to help more than sitting in front of a supercomputer..
Don Hanson

You can geek out on this from BikeTechReview (i.e. Kraig Willet): http://www.biketechreview.com/power/supercomputers.htm

Short answer: manage your effort so that the steeper the section you're on, the harder you work. The steeper the road, the more of your effort goes into fighting gravity rather than air resistance. Fighting gravity gives you a 1:1 effort:speed ration, so if you work 10% harder, you go 10% faster. But air resistance is (roughly) a 3:1 ratio, so you have to work 30% harder to go 10% faster. In other words, you get more for your effort the steeper the road, so work hardest when it's steepest.

That's the math, though gray's probably right that it's overthinking. Knowing this hasn't helped me in any TT's, I don't think, but I find the physics interesting.

 

[gray8110]

I don't think that our two opinions are that diametrecially opposed. I acknowledge completely that there are very valuable times where you can gain time with increased intensity followed by recovery. My point, and this is partially anecdotal but also backed by more than a few opinions of coaches and trainers, is that most of what makes up a TT performance is maintaining a pace that can be maintained - this doesn't say that difficulties in the course won't require changes in effort but in the grand scheme it should average out. Regardless, Kraig Willett's article is a very good read - I don't know that it contradicts my general point - it is an enlightening read.

I am curious about the "1:1 effort to speed ratio while fighting gravity versus 3:1 while fighting wind resistance." There's no point where one is completely independent of each other for one thing - the general consensus of opinion is that a ratio of power to weight takes precedence on climbs while a ratio of power to surface area is more relevant on the flat but the mathmatics is never as simple.

 

[wavylines]

I am curious about the "1:1 effort to speed ratio while fighting gravity versus 3:1 while fighting wind resistance."

I was refering to the fact that in the power:speed equation, the portion of power used to overcome wind resistance rises with the cube of speed, while that used to overcome gravity is linear. Of course, both are always present, and there's also rolling resistance and drivetrain inefficiencies. But in general, the steeper the road, the more gravity predominates, the flatter, the more wind. So on a flat road, the power:speed curve will look like a cubic function (where, very roughly speaking, a 1% increase in speed takes about a 3% increase in power), while on a steep road, it will look like a linear function (1% > power = 1% > speed). You're right that w/kg and w/CdA are the contolling terms, but the difference is that if you increase your w/kg by 10%, you'll do an uphill TT almost 10% faster, but if you increase your w/CdA by 10%, you'll only go about 3% faster on a flat TT.

And I agree that we're agreeing .

-- WL (not an engineer, but the son of one ...)