12strings

THE BACKGROUND: Tonight, something I already sort of knew was confirmed...I suck at riding fast.

Tonight was the last of our bike club's regular Monday Night group ride before Daylight Savings Time cancels it for us. It just so happened that I (someone who really just started riding fast, and with groups, this past spring) ended up riding with only 3 other guys: 2 Triathaletes, and one guy who is just a very fast and strong rider, all of whom have years of experience.

Our 25 mile route has 2 significant climbs, and 1 long descent that is followed by a long flat section. So here's what happened:
-First climb, I was able to keep up pretty well, though 2 of the guys started to pull away from the other 2 of us.
-Long Descent + Flat, all 3 took off, and kept pulling away from me even on the flats, until they got to our regular stopping point half-way through the ride where they waited for me. Also, one the next flatish section, I was able to keep up, but just barely, and felt like I was working harder than the rest of them. I just can't get comfortable riding at 21-23mph...
-Second climb - I led the way up the whole climb, and felt much more comfortable than on the fast flat sections...One of the more competitive guys passed me near the top, but I was able to chase him down without much trouble.

Due to the fact that our group was smaller this ride, there were not other riders that were a bit slower/weaker like me for me to stay with...it amplified and confirmed what has been the case all summer: I can beat lots of people on climbs, but not on gradual descents, or on the fast flat sections that follow those descents.

THE SCIENTIFIC EXPLAINATION I FOUND: (Link: Climbing vs time-trialling: same effort, different power output | CyclingTips)

Apparently there is something called Crank Inertial Load, that has to do with the very fast loading and unloading of power within the pedal stroke when riding at high speeds, since your inertia is taking care of most of your forward motion, you are only "topping off" the power on each stroke...whereas on a climb, you are applying power to a much larger portion of the pedal stroke, because inertia is not as great.

Apparently Fast-twitch fibers are actually better for this high-speed, time-trial-like effort...and slow-twich fibers are better for climbing. So there are some people who are great time-trialers who aren't great climbers...

I found the article very interesting...Some of this is in-born, and some can be improved with training...Much of my solo training has been focussed on hill repeats, and 30-second intervals, which are all acceleration, not much sustained speed...I guess I know what I need to work on now.

svtmike

Any other explanations to consider? What are your relative weights? Relative power?

12strings

For this specific ride, sure the simple fact that I fell behind and the 3 of them were riding together allowed them to draft, but the whole summer pattern is one that has me doing better at climbs than at sustained speeds on flats...

Fyi, if I had to guess:
Me- 160lbs, 5'9"
Tri guy 1- 165-170, 5'11
Tri guy 2 - 155, 5'7"
Biker guy-180, 5'10" this is the only guy who has any noticeable fat on him, but not much, he's older... the tri guys are big calfed machines.

Also, I ride unplugged, so no power numbers for you...

Drew Eckhardt 

Up-hill speed is increases approximately linearly with power-to-weight ratio. With lung area increasing with the square of height this tends to favor light riders that aren't too short - elite climbers tend to weigh under 2 pounds per inch.

Down-hill speed comes from the weight-to-drag ratio. A cyclist's speed increases with the square root of his weight as he gets fatter.

On flat ground speed comes from the power-to-drag ratio. Naturally bigger cyclists power may increase linearly with their mass, while frontal area only goes up with the 2/3 power of their weight.

I'm 5'9.5", and in good shape weigh 135-137 pounds with a 3.5-3.6W/kg power to weight ratio. I get up hills quickly.

Jumping out of airplanes, big people in the same body position wearing similarly tight jump suits can fall 15-25% faster.

On "flat" ground it takes me about 210W to average 20-21 MPH which is 95% of my one hour power in good shape. There are 185 pound guys with about the same drag for whom that's an all-day pace.

Carbonfiberboy 

Downhill and flats speed is mostly form on the bike. Work on that because that's free speed. Easier to decrease drag than to increase power. Practice riding low and with a flat back, knees brushing the top tube, elbows in as far as you can get them. You want your elbows in front of your knees as you pedal when low. Test hoods with forearms horizontal vs. same back angle and in the hooks. Sitting on the floor, you should be able to almost touch your knees with your nose, legs dead straight. Practice straightening your back by rotating your pelvis forward. Your back should be dead straight from your neck to the top of your butt. This opens your chest and reduces pressure on your heart. Use a mirror while on your rollers.

You also might look at your tires. Need low RR tires with plenty of pressure. Try Conti 4000s II in 23mm at 120 lbs. if you are riding carbon, 100-110 for anything else.

PepeM

I think it mostly boils down to tactics/strategy and of course, power. Sounds to me like (and since I don't know anything about you, take is as the completely uneducated guess it is), while you're keeping up in climbs, you're probably having to dig deeper than they are, which leaves you with less to give on the flats. Then on the flats you say it feels like you have to work harder than they have, which is true. They probably have higher FTPs than you, so they are comfortable putting out a constant power output which is not comfortable to you. Also, how good at you at drafting? Do you really hold on to the wheel in front of you, or are you constantly falling a bit behind (can be as little as a wheel length) and having to do small accelerations to catch up? All that adds up quickly, especially when going fast where drag becomes by far the main force to overcome. Lastly, you spend way longer on flats than on the climbs (well, usually, and your ride description seems to suggest it) so being able to keep up for the short period that the climb lasts doesn't mean you'll be able to keep up for the long period of fast riding on the flats.

I've read about crank inertial load. I really doubt that is your issue. While it is true that the whole fast twitch slow twitch probably limits who can become a great time trialist vs a great climber, you aren't either of those so I would be surprised if muscle composition is your limiter. I could be wrong of course, what with me knowing absolutely nothing about you.

My layman recommendation: Keep training to raise that FTP and keep doing fast group rides to become better at drafting and conserving energy. The last one in particular I have found pays off tremendously.

EDIT: Forgot one more: I know it feels great to beat people on the climbs, but maybe next time try to get over the hills with as little effort as possible instead of going all out. That will leave you fresher for what's coming next.

Carbonfiberboy 

One other thing you can try, which would benefit anyone, and does have something to do with inertial load:
Once a week, put your bike on your trainer or rollers and do as follows. Warm up with 15 minutes in zone 1. Put the bike in a very low gear and spin up to 115-120 rpm. Hold that cadence for 15 minutes, then cool down with another 15 minutes in zone 1. Over a period of weeks, gradually increase the fast pedal time to 45 minutes of continuous pedaling. If you can't reach that high cadence because you bounce, spin up until you are just below your your bouncing point and hold that. Your maximum cadence will gradually increase.

Relax your feet and keep them flat. No ankling. Imagine that you have a cushion of air between the bottoms of your feet and your insoles. Pedal mostly with the shoe uppers. Don't run your heart rate way up. Try to do the whole fast pedal in zone 2, so a very low gear. You'll gradually get better at this, and yes, this will help you on the flat . . . and climbing, too.

You really need a trainer or rollers for this for two reasons: There's not usually enough room on the road to do anything for a steady 45 minutes, and your momentum on the road makes it too easy.

I disagree about the tactics thing. Most group rides back off the intensity after the climbs. You shouldn't have big trouble holding their wheels. Whup 'em on the climbs, then trade pulls on the flat, that's the thing. You can bet your sweet bippies they aren't just letting you whup them on the climbs without a battle. They have to be hurting at least as bad as you, probably worse.

12strings

Thanks for all the good input. I'm definitely just beginning this whole thing, though I commuted to work for several years, Just started riding faster and with groups this past spring. I'm still gaining skill at things like drafting, descending, and such.

It probably comes down to what I have trained for. Once I started riding with a group, I realized last spring that my climbing was really bad, (having avoided hills like the plague when choosing my commuting routes). So for the last 3-4 months, I have been doing one group ride a week, and 1-2 shorter rides which were focused primarily on climbing, with a few 30 second sprint intervals thrown in. I got better at everything, but very quickly got a lot better at climbing (According to strava, one climb that took me 12:36 in may, I just did in 8:04 last night).

So definitely I need to work on holding a sustained high-speed in high gears. That is difficult in my area. "Flats" here means gently rolling hills, they are interspersed among the valleys and ridges and climbs ranging from 5%-15% at places.

Finally, I'm not really that depressed about it. It just so happened that this night it was me and 3 of the fastest guys, 2 of which have done full-length ironmans...so they've got their sustained power really dialed in......usually there is 8-12 riders, and about 4-5 of them are about my speed, and a few are weaker.

PepeM

Hard to trade pulls when you're being dropped.

Yes, that is a good idea. If you want to go fast, you need to get used to going fast. That's why things like motor pacing exist. It's ok if the terrain around you is rolling hills, that's what you'll be riding on your group rides anyway. Just try to keep a high constant effort throughout. Ride based on effort, not on speed.

Carbonfiberboy 

One more thing you can try that's rather after the moto-pacing idea:
Go out and ride fairly hard at a steady 100 cadence, shifting as necessary to hold that steady cadence yet not blow up. Make that a 30 minute interval, rest 5 minutes, then go back along the track for another 30 minute interval. You'll have to adjust your effort to be able to hold it fairly steady and at a level you can hold for 30 minutes. So that means pedal the downhills too. If you run out of gears descending, of course just keep increasing the cadence, then drop it back to 100 when you can. Climbing, if you run out of gears, just do what you can, but don't go too hard, then pick it back up to 100. You'll probably be using much smaller gears than you usually use. That's fine and doesn't matter to the effectiveness of the training.

12strings

I generally feel like I have got the cadence thing down pretty good. I spin up hills, not mashing. In fact, a few weeks ago one of the more experienced riders told me I needed to slow down my cadence because it looked like it was over 100. But I tend to use my gears to their fullest, which means spinning a lot, shifting early on hills, rarely pushing that hard. This may have caused me to not build up some leg strength.

Interestingly, it is more on the downhills, and the flats immediately following where I tend to get into trouble of being in too high a gear, and slowing my cadence down....then I have to correct for that and have trouble finding a comfortable gear.

Drew Eckhardt 

It could be they're not working very hard on climbs. When I'm not riding intervals I try for a steady power output regardless of grade - usually below my aerobic threshold on most rides so I train my oxidative energy system and slow twitch fibers, occasionally 95% of one-hour power for 1:15 or 1:30.

Your climbs are relatively short (8:04) so you can rely on anaerobic power, while their better trained slow-twitch fibers give them an advantage on flat terrain.

They probably have better aerodynamics than you too.