Please help me understand fast riding at relatively low watts

I’m trying to wrap my head around this and I feel like I’m missing something (or possibly everything).

I recently did a nice slightly hilly ride on my road bike. Three hours, 19.3 mph average, 217 average watts (NP=253), 3200 feet of climbing.

Then I go and read Steve’s (@darkhorsetri) IMAZ race report (http://forum.slowtwitch.com/forum/Slowtwitch_Forums_C1/Triathlon_Forum_F1/'16_IM_Arizona_RR_-_Lucky_%2313...with_an_8%3A48_PB.__P6162799/?page=unread#unread)

wherein he has the same average power output and averages 23.75 mph on the bike, 4.5 mph faster.

Given the caveats of

  1. Decent road bike with a good fit and crappy wheels vs optimized tri bike with aero wheels
    and
  2. More climbing for me, approximately 1000 feet per hour vs approximately 350 feet per hour

doesn’t 4.5 mph seem like a very large delta in speeds? Or does that seem totally reasonable to you all? Like I said, I feel like I’m missing something.

-Colin

I’d start by comparing watts/kg of weight. Put my 200 watts on a skinnier body and it goes a lot faster.

Did you do all of your climbing in aero?
You loose more energy to going down fast to aero drag than you save by going slow up the hill.

Totally reasonable difference. Here are three recent samples for me (155lbs).

–IMAZ for me = 23.0 mph on 207 AP/NP (7 minutes slower than Steve).

–100 mile flat training ride (~90% in aero position) on tri bike (same power meter) = 21.0 mph on 200 AP/205 NP

–80 mile rolling training ride on road bike (diff. power meter, but same brand) = 17.7 mph on 208 AP/225 NP

This should highlight the importance of staying in aero position.

You really can’t compare a training ride on a road bike and a race on a tri bike and expect there to be similarities in speed.

Bike, wheels, tires, helmet, clothing all play a part in your speed for a certain power output; and all are in favor of the triathlon race.

Plus the much different course, not having to stop for stop signs, not dealing with traffic, etc.

19.7 mph seems good for your watts on a road bike; My average speeds are usually 17-18 mph and my power is roughly the same but the terrain is very rolling here.

Perfectly reasonable numbers. I reckon I’d be about 30 minutes faster than Steve on those same watts, so other really comes down to w/CdA (especially on such a fast course).

When it comes to hills it really depends on how steep they are as there’s a point where the extra power produced sitting up is more beneficial than the CdA reduction of your aero position. Thinking of 50 mile TTs, I was 10 minutes faster on one with under 1000ft of climbing as compared to one with 3600ft on slightly less power.

Do you wear a skinsuit and aero helmet on your training group rides? If not, you are losing a ton of speed there that is certainly affecting your average compared to a racer that is decked out in the most aero gear.

Pretty light traffic, nothing to really ‘deal’ with. Average speed is on riding time, not total time.

Thanks.

Big people need more power, in many cases they can produce more power just because they are bigger.

Many small people can go fast on little power just because they punch a small hole in the air.

How does your size compare to his?

About the same. I go ~155-160 pounds, 5’10".

Are you including zero’s in your avg power?

I’m trying to wrap my head around this and I feel like I’m missing something (or possibly everything).

I recently did a nice slightly hilly ride on my road bike. Three hours, 19.3 mph average, 217 average watts (NP=253), 3200 feet of climbing.

Then I go and read Steve’s (@darkhorsetri) IMAZ race report (http://forum.slowtwitch.com/.../?page=unread#unread)

wherein he has the same average power output and averages 23.75 mph on the bike, 4.5 mph faster.

Given the caveats of

  1. Decent road bike with a good fit and crappy wheels vs optimized tri bike with aero wheels
    and
  2. More climbing for me, approximately 1000 feet per hour vs approximately 350 feet per hour

doesn’t 4.5 mph seem like a very large delta in speeds? Or does that seem totally reasonable to you all? Like I said, I feel like I’m missing something.

-Colin

You are comparing race data to training data. That is not even close to an apples to apples. For one, in races you usually don’t have to obey traffic laws that is a biggie right there.

For the record, I think TJ went 4:11 on ~255 watts which blow my minds

Heck I was I just out there for S&Gs and went 238 for 4:22 https://www.strava.com/activities/781736566

Nope. Those times/numbers are all based on moving time, stops are removed.

Thanks,
-Colin

For the record, I think TJ went 4:11 on ~255 watts which blow my minds

It shouldn’t blow your mind. It should simply tell your reasonable mind that either a) he had serious wind doping at his aid or b) his power meter is broken AF.

Simple stuff, really. No chance he goes that fast solo on 255 genuine average watts. It’s just not happening.

Nope. Those times/numbers are all based on moving time, stops are removed.

Thanks,
-Colin

Doesn’t matter if the actual stops are removed. Slowing down and starting back up are significant drains on your average speed, as are slowing slightly approaching intersections, traffic, etc.

Comparing speeds vs power between training rides and races is not even close to apples to apples as TG noted.

Nope. Those times/numbers are all based on moving time, stops are removed.

Thanks,
-Colin

I guess I don’t understand how you have it setup. In training, your clock may be stopping, but how are you accounting for slowing down and speeding back up from stops or slow-downs. I assume your time is running then. That doesn’t happen in races. In races, you have the constant motion and hopefully very little braking.

Ah, yes, thanks. Sorry I didn’t see what you were getting at before, excellent point.

I will say, all things considered, this is a pretty slowdown free ride. One u-turn, four traffic stops over the course of the 60 miles.

For the record, I think TJ went 4:11 on ~255 watts which blow my minds

It shouldn’t blow your mind. It should simply tell your reasonable mind that either a) he had serious wind doping at his aid or b) his power meter is broken AF.

Simple stuff, really. No chance he goes that fast solo on 255 genuine average watts. It’s just not happening.

Are you just poking fun or are you being serious here. I honestly haven’t given it a lot of thought, but the course seemed relatively fast this year for whatever reason. Can you back calculate his .cDa from this. Based on prior conversations, it is possible his .cDa at 0 is in the .215 range but it is nearly impossible to account for the nearly 2500 athletes who were on the course and pushing a huge amount of wind as a group. We have already seen in prior analysis in years past how every single age group goes slower and slower for each lap speed-wise, however with the pros tend to go faster on lap 2 than lap 1, even though the power tends to be higher in lap 1 than lap 2.

Ah, yes, thanks. Sorry I didn’t see what you were getting at before, excellent point.

I will say, all things considered, this is a pretty slowdown free ride. One u-turn, four traffic stops over the course of the 60 miles.

There are a slew of other factors that I neglected to mention to keep it simple, but some include:

  1. Race day position awareness - you tend to actually think about things like maintaining a good tuck - on training day you have to be more attentive. This includes both keeping the head higher for oncoming traffic but also looking behind you more. You may refrain from getting up from the saddle to stretch it out more in a race as well.

  2. Equipment - On race day you usually ride race equipment. Ie, race tires, race tubes, aero helmet, clean bike, clean chain, remove excess frame bottles (each bottle is adding roughly 55 grams of drag), race wheels, race clothing that is tight fighting.

  3. Pacing - that was quite a large differential in power between AP and NP. That wouldn’t most likely be optimal on race day. Even on hilly course you want .IF to be way lower than what you have there.

  4. Slip-streaming - the rough equation is that it is 1 second per person passed if you take advantage of slip-streaming. It also gives you a chance to get up and stretch and have less drag than doing it out in the open.

  5. Course difficulty - you cherry picked one of the fastest courses out there. At AZ you had amateurs going 4:3X and quite a few. A whole slew in the 4:4x, and just increases from there. At the flip-side. Take a race like Ironman Wisconsin. You had a former pro ride sub 5hr, but no other amateur broke 5 hrs. So you are talking about a 30min difference. Factor that into the Avg MPH and you are going way way down.

it is nearly impossible to account for the nearly 2500 athletes who were on the course and pushing a huge amount of wind as a group

Right, so he was wind doping in the purest sense of the phrase. I am being serious but of course I am also goading you a bit. There’s simply no way, unobstructed, that a guy that size goes 4:11 on 255 watts. If you don’t believe me, read rappstar’s posts on this same subject in the past regarding Frodeno’s performance at Roth. It just doesn’t jive with the available modeling and data.

By the way, I find the assertion that his real life effective CdA is ~0.215 to be preposterous. However, given that the Marquise grants him another 100 grams of drag reduction…oh wait, only fools believe that nonsense.