What Did Your Power Do When You Got Lower In Front?

Jan 31, 16 7:37

Post #1 of 47 (5198 views)

My question is while working on position to get aero what have you all accepted (or observed) if any in power loss on your TT/Tri bike?

Some background: I'm an AG roadie trying to minimize my losses to the fast guys during TT's for a couple stage races and a TT series down here in AZ. I have always been a little reluctant to get too low on the front due to a history of back problems. In 2014 I would have characterize myself as a moderately powerful brick. 2015 I was a little more aero but didn't make any huge changes other than finding a saddle that seemed to allow me to relax my shoulders... (hard to describe). Going into 2016 over a few months I have lowered the front 4cm. Anyways, there is a short TT series down here in AZ and I completed the 20k much faster in 2015 than 2014 and just clocked 1:10 faster this year compared to last year. It's slightly down and a tailwind out and up headwind back. I fully understand conditions make it not an apples to apples comparison but, I actually think conditions this year were windier than last. So, compared to last year I was an avg of 10W less but, that 1:10 equates to about 0.8-0.9mph faster. FWIW, my FTP seems to be really close now compared to last year at this time and 2014. Same bike. Pacing was similar on the first leg but, I really lost it in the middle 1/3rd of the 2nd leg. So perhaps a mental/pace issue. Still, interested what some of you have observed.

Whew! Lots of info but, this is the first season I really have had a chance to get low enough to see a drop in wattage. Testing will continue...

Re: What Did Your Power Do When You Got Lower In Front? [woodys737] [ In reply to ]

Jan 31, 16 8:53

Post #2 of 47 (5134 views)

We've tested and have seen people get faster due to reduced drag as they got lower and we've also seen people come up and reduce drag.

We've seen people scrub some watts by moving lower but end up faster bc their drag reductions where so large.

What series in AZ? I'm located in AZ and wouldn't mind jumping into a few TT's.

Brian Stover USAT LII
Accelerate3 Coaching
Insta

Re: What Did Your Power Do When You Got Lower In Front? [woodys737] [ In reply to ]

Jan 31, 16 9:09

Post #3 of 47 (5111 views)

woodys737 wrote:

My question is while working on position to get aero what have you all accepted (or observed) if any in power loss on your TT/Tri bike?

Some background: I'm an AG roadie trying to minimize my losses to the fast guys during TT's for a couple stage races and a TT series down here in AZ. I have always been a little reluctant to get too low on the front due to a history of back problems. In 2014 I would have characterize myself as a moderately powerful brick. 2015 I was a little more aero but didn't make any huge changes other than finding a saddle that seemed to allow me to relax my shoulders... (hard to describe). Going into 2016 over a few months I have lowered the front 4cm. Anyways, there is a short TT series down here in AZ and I completed the 20k much faster in 2015 than 2014 and just clocked 1:10 faster this year compared to last year. It's slightly down and a tailwind out and up headwind back. I fully understand conditions make it not an apples to apples comparison but, I actually think conditions this year were windier than last. So, compared to last year I was an avg of 10W less but, that 1:10 equates to about 0.8-0.9mph faster. FWIW, my FTP seems to be really close now compared to last year at this time and 2014. Same bike. Pacing was similar on the first leg but, I really lost it in the middle 1/3rd of the 2nd leg. So perhaps a mental/pace issue. Still, interested what some of you have observed.

Whew! Lots of info but, this is the first season I really have had a chance to get low enough to see a drop in wattage. Testing will continue...

That's a long post just to tell us how much faster you've gotten. ;)

Seriously though, power is simply one of many variables in the equation of speed. The goal is speed. You rode an average of 10W less but why? Because you are, indeed, 10W less effective or was it due to how you felt, what you ate, how exhausted you were when you started, how you slept, etc.? Are you still adapting to the position? As you pointed out, it could be a mental/pace issue.

Ultimately, you have a very limited data set from which to draw any conclusions. Don't overthink things in the meantime, keep riding faster, and keep gathering info if you want a more conclusive answer to your question on how much power you've actually lost due to the position change.

And congrats on the speed improvement. It's amazing how much speed people leave out on the table from ignoring aerodynamics and a good bike fit.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)

Re: What Did Your Power Do When You Got Lower In Front? [desert dude] [ In reply to ]

Jan 31, 16 9:14

Post #4 of 47 (5105 views)

Hey Brian It's Woody (Swiss...). Really want to podium fro VOS which comes down to the TT. Last year there was a series that I think included Cottonwood1 & 2, RAT 1 & 2, 3 Bears 1 & 2 and not sure if VOS, TBC are included or the hill climbs at the end of the season.

Re: What Did Your Power Do When You Got Lower In Front? [trentnix] [ In reply to ]

Jan 31, 16 9:21

Post #5 of 47 (5096 views)

Yeah I know. Sorry. TMI but, I never know where the line is with giving enough info to get what I'm looking for. While I'm getting faster I am still slow. Just absolutely amazed how many fast guys around.

You nailed the problem with 10W for sure. It could be due to hydration, rest, training in general and on and on. I was more curious in what some good guys (many here) have experienced. Not that it will change what I do but, I very well may learn something incidentally.

Re: What Did Your Power Do When You Got Lower In Front? [desert dude] [ In reply to ]

Jan 31, 16 9:43

Post #6 of 47 (5070 views)

desert dude wrote:

We've tested and have seen people get faster due to reduced drag as they got lower and we've also seen people come up and reduce drag.

We've seen people scrub some watts by moving lower but end up faster bc their drag reductions where so large.

This is really interesting.

I've decided I want to get serious about aero position - how do I know (without a wind tunnel) whether I'm better being higher or lower?

Re: What Did Your Power Do When You Got Lower In Front? [AforEffort] [ In reply to ]

Jan 31, 16 9:46

Post #7 of 47 (5064 views)

AforEffort wrote:

desert dude wrote:

We've tested and have seen people get faster due to reduced drag as they got lower and we've also seen people come up and reduce drag.

We've seen people scrub some watts by moving lower but end up faster bc their drag reductions where so large.

This is really interesting.

I've decided I want to get serious about aero position - how do I know (without a wind tunnel) whether I'm better being higher or lower?

Field testing.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)

Re: What Did Your Power Do When You Got Lower In Front? [trentnix] [ In reply to ]

Jan 31, 16 9:57

Post #8 of 47 (5046 views)

trentnix wrote:

AforEffort wrote:

desert dude wrote:

We've tested and have seen people get faster due to reduced drag as they got lower and we've also seen people come up and reduce drag.

We've seen people scrub some watts by moving lower but end up faster bc their drag reductions where so large.

This is really interesting.

I've decided I want to get serious about aero position - how do I know (without a wind tunnel) whether I'm better being higher or lower?

Field testing.

Basically just trying the same route with different setups?

I have a closed track near me. How many trial runs, of what distance, should I do for each setup?

Re: What Did Your Power Do When You Got Lower In Front? [woodys737] [ In reply to ]

Jan 31, 16 10:13

Post #9 of 47 (5020 views)

Hey, here's a tip that worked for me. Get all your tools to adjust your seat, seatpost, and bars out and get on the trainer and ride for a while to warmup. Wear a HRM and have either speed or watts available too.

After about 20 to 30 minutes, start dropping your bars until just before the point where your HR starts rising for the same speed/watts as before. If your HR starts climbing, then you're squishing your chest and not able to breathe enough to keep up the output you were doing before. When you hit that point, that's just a tad too far. And remember, you often want to bring the seat down a tad with the bars as well.

Also, remember the biggest problem is raising your HR compared to before. If your speed/watts go down a tiny bit but HR stays OK, that's still OK. You won't put out quite as many watts in a newer position because you haven't spent years in it getting efficient at it yet.

Do this and the next time you go ride, you should be lower, tighter, and faster at the same HR. Works like a charm.

----------------------------------------------------------
Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com

Last edited by: ZenTriBrett: Jan 31, 16 10:14

Re: What Did Your Power Do When You Got Lower In Front? [ZenTriBrett] [ In reply to ]

Jan 31, 16 14:12

Post #10 of 47 (4809 views)

Excellent idea Zen. Need to find a HRM. I've only used power for some years now..

Re: What Did Your Power Do When You Got Lower In Front? [woodys737] [ In reply to ]

Jan 31, 16 14:51

Post #11 of 47 (4771 views)

For me there is almost an "on/off switch" for aerobar height and power production. When I set up my Shiv TT (M) I tried running the bars slammed with no spacers (I'm a flexible guy") and I couldn't get within 30w of my normal TT pace, even worse at high cadences. I added 20mm of spacers and I was flying as normal. Same thing with other frames. I think its a hip impingement thing given UCI rules but not sure.

Professional Athlete: http://jordancheyne.wordpress.com/ http://www.strava.com/athletes/145340

Coaching Services:http://www.peakformcoaching.com/

Re: What Did Your Power Do When You Got Lower In Front? [AforEffort] [ In reply to ]

Jan 31, 16 15:41

Post #12 of 47 (4737 views)

Basically just trying the same route with different setups?
I have a closed track near me. How many trial runs, of what distance, should I do for each setup?

Do you have a powermeter? What sort of track?

You can't go by heart rate.

Re: What Did Your Power Do When You Got Lower In Front? [woodys737] [ In reply to ]

Jan 31, 16 16:46

Post #13 of 47 (4663 views)

With 11cm of drop I've found my heart rate at race pace wattage is basically the same whether sitting up on the basebars or in aero position in the aerobars. Logically, that seems decent to me.

-------------------
Madison photographer Timothy Hughes | Instagram

Re: What Did Your Power Do When You Got Lower In Front? [AforEffort] [ In reply to ]

Jan 31, 16 17:20

Post #14 of 47 (4622 views)

AforEffort wrote:

trentnix wrote:

AforEffort wrote:

desert dude wrote:

We've tested and have seen people get faster due to reduced drag as they got lower and we've also seen people come up and reduce drag.

We've seen people scrub some watts by moving lower but end up faster bc their drag reductions where so large.

This is really interesting.

I've decided I want to get serious about aero position - how do I know (without a wind tunnel) whether I'm better being higher or lower?

Field testing.

Basically just trying the same route with different setups?

I have a closed track near me. How many trial runs, of what distance, should I do for each setup?

Check out the Platypus thread, lots of great info on field testing. http://forum.slowtwitch.com/...ng=platypus;#3536905

Also check out this thread. http://forum.slowtwitch.com/..._reply;so=ASC;mh=25;

Re: What Did Your Power Do When You Got Lower In Front? [woodys737] [ In reply to ]

Feb 1, 16 4:28

Post #15 of 47 (4431 views)

My power stays the same regardless of how low I get in the front. What doesn't is my CdA. It goes down until I hit a sweet spot and then it climbs drastically.

Re: What Did Your Power Do When You Got Lower In Front? [Grill] [ In reply to ]

Feb 1, 16 4:41

Post #16 of 47 (4415 views)

Grill wrote:

My power stays the same regardless of how low I get in the front. What doesn't is my CdA. It goes down until I hit a sweet spot and then it climbs drastically.

That's what happens with me as well.

jaretj

Re: What Did Your Power Do When You Got Lower In Front? [woodys737] [ In reply to ]

Feb 1, 16 6:53

Post #17 of 47 (4276 views)

My FTP delta TT position to road position on the hoods is about or close to 30 watts. That said I spend about 90% of my time riding on the road bike. I hope to close that delta this year due to more training on the TT bike.

All that said my TT position would appear to be quite aero due to my results compared to others based on my race results and power. My one hour power on the TT bike is just under 4.5w/kg.

Again I hope with more time in the TT position I can better prepare myself to close that delta a bit. I absolutely do not expect it to get to zero.

24 Hour World TT Champs-American record holder
Fat Bike Worlds - Race Director
Insta: chris.s.apex

Re: What Did Your Power Do When You Got Lower In Front? [woodys737] [ In reply to ]

Feb 1, 16 8:47

Post #18 of 47 (4206 views)

When I went from 10cm drop to 15cm drop, I lost about 20W at FTP, from about 290W to 270W. I did put bike splits faster, but would loose it all on the run due to messed up hip flexors.......Went back up to about 11.5cm drop and got faster as I was able to bring my FTP back up to 295-300W. So yes, I think one can be too low in the front. This was a pure trail/error and observation over same routes and same courses.

Re: What Did Your Power Do When You Got Lower In Front? [trentnix] [ In reply to ]

Feb 2, 16 20:47

Post #19 of 47 (3968 views)

trentnix wrote:

AforEffort wrote:

I've decided I want to get serious about aero position - how do I know (without a wind tunnel) whether I'm better being higher or lower?

Field testing.

Without a wind tunnel, I'd suggest first using a full length mirror, humanipers, or digital imaging to help quantify the demand side of things before trying to do any field testing with power. Explore both reach and drop. These low-tech demand side quantification approaches I've suggested will likely save you either time or money in the early stages...

If you have an excess of time, it's possible to get good demand side quantification results using a reliable power meter in the field under dead calm conditions. This style of field testing is tedious work and isn't for everyone - don't be fooled here. For novice/inexperienced field testers, it's a tough row to hoe to get reliable results. Caveat emptor.

If you have an excess of money, it's possible to get good demand side quantification results for a variety of ambient wind conditions in a wind tunnel.

Field testing by power is really the only way to go when trying to quantify the supply side of things regardless of one's experience level.

=================
Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

Re: What Did Your Power Do When You Got Lower In Front? [desert dude] [ In reply to ]

Feb 2, 16 20:55

Post #20 of 47 (3961 views)

desert dude wrote:

we've also seen people come up and reduce drag.

off the top of my head, I can think of about 1 out of 150 folks that I've witnessed being tested in the tunnel that when controlling for all other variables, a smaller drop reduced axial force...but the team director's mind was made up in that one outlier case and we weren't able to explore the fishy-ness any further.

=================
Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

Last edited by: BikeTechReview: Feb 2, 16 20:58

Re: What Did Your Power Do When You Got Lower In Front? [jaretj] [ In reply to ]

Feb 2, 16 21:34

Post #21 of 47 (3936 views)

jaretj wrote:

Grill wrote:

My power stays the same regardless of how low I get in the front. What doesn't is my CdA. It goes down until I hit a sweet spot and then it climbs drastically.

That's what happens with me as well.

jaretj

out of curiosity, what do you guys do when tucking on a high speed descent? ...get real low and then raise your torso until you find that sweet spot?

=================
Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

Re: What Did Your Power Do When You Got Lower In Front? [BikeTechReview] [ In reply to ]

Feb 3, 16 3:17

Post #22 of 47 (3825 views)

On a high speed decent where I'm not pedaling I put my hands on the horns, keep my elbows in and put my shoulders right near the pads.

My butt moves back slightly so I can get my back flatter

It's basically as low as I can get and still be able to turn my head up and see where I'm going. I can do the same on my road bike while on the drops on fast straight descents but as soon as I come up to a turn (like descending mountains in Georgia) I need to position myself to apex the turn correctly.

On a fast decent where I am pedaling (normally under 32mph) I'll do my best to make myself as narrow and low as possible while staying in the aero bars.

Edit: There is somewhere while riding 22-26mph when going lower has resulted in slower bike time in my races. At first I thought it was just a particular instance but it happened several times last year in training and races. Before LCN in September I raised myself up to where I had been the previous year (not much higher) and speed to power was back in the range I expected. Perhaps my change was not as drastic as Grill's was.

jaretj

Last edited by: jaretj: Feb 3, 16 3:24

Re: What Did Your Power Do When You Got Lower In Front? [Timtek] [ In reply to ]

Feb 3, 16 9:07

Post #23 of 47 (3721 views)

Timtek wrote:

With 11cm of drop I've found my heart rate at race pace wattage is basically the same whether sitting up on the basebars or in aero position in the aerobars. Logically, that seems decent to me.

That's certainly decent in terms of not losing any power in your aero position. But it doesn't tell you if you have an aerodynamically fast position. I lose about 10-20 watts in my aero position compared with the drops, but I save a lot more than that in aero. If I set my position solely on not losing power, I'd definitely leave significant speed on the table. The power drop is mostly significant when climbing hills, and then I either choke up to reduce the effective drop and open up my hip angle, or if it's steep I'm on the drops anyway.

The actual amount of drop is meaningless as it depends on your upper arm length and how stretched out you are, but for reference, at 5'9" my sweet spot is 14 cm of drop. When I was running 10 cm drop I was quite a bit slower even though I was a bit more powerful. I was able to partly minimize the power loss by moving my saddle more forward. But a lot of triathletes ride with the saddle forward even with low drop so that's not necessarily going to help them. I also ride more stretched out than most triathletes, who seem to like choked up positions, and who thus at the same size/upper arm length would need more drop.

Re: What Did Your Power Do When You Got Lower In Front? [atasic] [ In reply to ]

Feb 3, 16 9:22

Post #24 of 47 (3698 views)

atasic wrote:

When I went from 10cm drop to 15cm drop, I lost about 20W at FTP, from about 290W to 270W. I did put bike splits faster, but would loose it all on the run due to messed up hip flexors.......Went back up to about 11.5cm drop and got faster as I was able to bring my FTP back up to 295-300W. So yes, I think one can be too low in the front. This was a pure trail/error and observation over same routes and same courses.

That's a very drastic change in drop and might need a long time for adaptation. Also, I needed to move my saddle forward in conjunction with going lower, when I just went lower it strained my hips and reduced my power. If your FTP went to a higher level at the intermediate height rather than the highest height, how are you sure that isn't a change in fitness rather than position-related?

Not doubting it's possible to go too low, I've gotten to the point of no further returns but not higher drag in my own testing. But I think a lot of people never iterate enough to get to that point.

Re: What Did Your Power Do When You Got Lower In Front? [Grill] [ In reply to ]

Feb 3, 16 9:50

Post #25 of 47 (3663 views)

Grill wrote:

My power stays the same regardless of how low I get in the front. What doesn't is my CdA. It goes down until I hit a sweet spot and then it climbs drastically.

Sorry for the basic question, but how does one go about measuring or estimating their CdA (when wind tunnel is not a feasible option)? Think I saw mention of a site/tool that estimates CdA a while back but didn't grasp the idea - is it something like you ride the same stretch of road at the same wattage in different positions and there's software to estimate you CdA based on the speed the different positions equate to?

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