Login required to started new threads

Login required to post replies

Cameron Wurf, Josh Amberger and Tim Reed bike position changes : improved bike and improved run ?
Quote | Reply
"Rest" noted in the Josh Amberger interview thread that Josh and Tim increased their stack heigh for Kona this year.

Checking pictures, I noticed :
1) Tim Reed increased his stack height for Kona from Santa Rosa or Coeur d'Alene races
2) Josh Amberger increased his stack height also for Kona from Boulder race

Looking more precisely, the first photo I found of Josh TT bike with high stack is 23 august 2019, in Josh Facebook, after one week in Andorra.

Hmmm Andorra....(Cam Wurf leaves there)
Hmmm Tim Reed... (Cam Wurf buddy from Lord Howe Island)

Looking at Cam Wurf stack height :
2018 Roth : high stack
2018 Biomechanics study : high stack : https://www.triathlete.com/...s-top-cyclist_333693
2018 Wind Tunnel with new disk bike : ???
2018 Kona : LOW STACK
2018 Challenge Daytona : LOW STACK
2019 January training with Gearing Thomas in LA : BACK TO high stack
2019 Cannes : high stack
2019 Roth : high stack
2019 Italy : high stack with integrated cockpit on the new Kona bike
2019 Kona : high stack

So Cam Wurf tested lower stack, possibly from his pre-Kona 2018 wind tunnel. He used lower stack in Kona, Daytona, then for 2019 came back to higher stack.

These are facts... now let's go for some intuitions :

1) From 2018 pre-Kona wind tunnel, Cam Wurf tested several configs and choose a config "low stack" may be more aero, more adapted to optimizing bike leg.
2) He get Kona bike leg record.
3) For 2019, focusing on getting the run more efficient, he run much more (kind of doubling run volume) and come back to a more running friendly bike position - with or without aero penalty ?
4) he share his experience with Reed (his old buddy) and Amberger (during Andorra session), both choose also to increase their stack heigh

Side note 1 : increase stack heigh can bring aero penalty but facilitate power production, so little impact on bike leg ?
Side note 2 : increase stack heigh can help the run ?
Side note 3 : you might increase stack heigh, but not changing hip angle and back position, just "turtle" more, which improve aero especially if mantis position, as the head disappear more behind the hands ?

Is it possible increased stack help the run, facilitate bike power production, with no/little aero loss (if well studied) ?
Last edited by: Pyrenean Wolf: Oct 30, 19 5:09
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [Pyrenean Wolf] [ In reply to ]
Quote | Reply
You use "high stack" inaccurately. If you look at the excellent photos on Tririg's site, all three of these riders currently have stacks that by your average age group rider standards are actually pretty low. Amberger has the least drop, which I'd describe as moderate stack, but he's also the most stretched out of the three and the further forward your forearms are, the higher your pads need to be to achieve the same shoulder height.

Rather, they may have raised their stack because if your drop is too great it makes it hard to "shrug" and "turtle". Those actions result in a significantly lower height of the head and upper body with the same armpad drop.

I'm rather dubious of the claim that the somewhat increased stack has anything to do with being able to run better. Rather, it's better understanding the techniques that enable one to ride in the most aerodynamic position.

All this discussion of "high stack" is quite relative and easily misinterpreted by your average age grouper to justify their barn door positions.
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [Pyrenean Wolf] [ In reply to ]
Quote | Reply
not sure why they changed.

For me, there's a small bit of difference at low yaw between high stack and low stack (lower is better) but a big difference at high yaw (lower is better). For Kona, I'd go with my lowest position possible... average yaw of 15 degrees this year.

Eric

Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [tttiltheend] [ In reply to ]
Quote | Reply
 
Yes, I can evaluate a saddle to pad drop on a picture.
Yes, I know Wurf, Amberger and Reed drop, before and after change.

I'm sure you can understand that when I say "high stack", I'm talking about their new increased stack.
And indeed I know the pro can have a saddle to pad drop higher than AGers, even when they increase their stack height, and even when I use the word "high stack" to talk about a drop higher than an average AG drop.
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [Pyrenean Wolf] [ In reply to ]
Quote | Reply
Pyrenean Wolf wrote:

Yes, I can evaluate a saddle to pad drop on a picture.
Yes, I know Wurf, Amberger and Reed drop, before and after change.

I'm sure you can understand that when I say "high stack", I'm talking about their new increased stack.
And indeed I know the pro can have a saddle to pad drop higher than AGers, even when they increase their stack height, and even when I use the word "high stack" to talk about a drop higher than an average AG drop.

I don't doubt at all that you understand that, but the average reader here may not, so that's why I made the point.

The other point I'd make is that while the pros generally have larger drops and better positions than most age groupers, there's no particular reason that has to be the case. I've never had anywhere near the aerobic capacity of the pros, but I have just as good a position as a lot of them. So I'm still a lot slower than the pros, but I'm faster than a lot of other people with comparable athletic ability to myself. Not only that, I'm in my mid-sixties, so if I can do it, so can most amateur age groupers. I'd posit that aerodynamic positioning one of the areas in which most committed amateurs can in fact do just as well as the pros. (Sure, there are some people with bio-mechanical limitations, but they're the minority.) It's just a matter of having the right mindset and putting in the work to evolve a good position.
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [ericMPro] [ In reply to ]
Quote | Reply
 
Yes it is interesting.

Reed move up slightly
Amberger move up more significantly
Wurf came back to its "pre- Kona 2018" stack, about 3 or 4 cm higher

If aero losses, specifically at yaw (indeed typically the case in Kona) are on one side of the balance, what is/are the gains ?

Muscles efficiency on the bike ?
Preparing a better run ?

- Bike leg side :
Alex Dowsett, ex- hour record holder, 5th this year in the TT worlds, 6 time UK TT champs, was already quite high (10 or 11cm drop for 182cm heigh) and is not going down, seems to me this year he increased slightly his stack to a less than 10cm drop, clearly saying "lower is slower" :
https://www.instagram.com/p/BzSc3nMl2Vh/

Spoiler alert : he is not running after TT :-)
Clearly he identify some interest on the bike leg. Ok, only 1h bike leg, at FTP.
Apparently, at FTP or higher, it is more efficient for him to stay relatively high (for a pro). Muscle efficiency gain > Aero loss ?

- Run leg side :
Any evidence that opening the hip angle in the bike save muscles for the run (gluten, hamstring, quads) ?
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [tttiltheend] [ In reply to ]
Quote | Reply
I understand,

I'm also quite old (53) and not very strong. So I take care of my CdA !

I'm 182 cm (6'), same size as Wurf or Dowsett (my inspirations in Tri / TT), and nearly same weight (less muscles and more fat, however).
On the track I was using a drop of - 135 to 150 mm for IP and TP.
Currently I use a drop of -135 mm for 70.3 triathlons, same as I was using for TT.

But considering to go a bit higher, for confort, visibility (I use glasses, and on the road I need to push my head up, an effect I did not had on my beloved olympic wooden track), and.... running efficiency ?
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [ericMPro] [ In reply to ]
Quote | Reply
ericMPro wrote:
not sure why they changed.

For me, there's a small bit of difference at low yaw between high stack and low stack (lower is better) but a big difference at high yaw (lower is better). For Kona, I'd go with my lowest position possible... average yaw of 15 degrees this year.

Eric

Who measured the 15 degree average yaw at kona this year? Interesting to see another “typical” windy kona. Shivs and ia’s would be loving it.
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [Rocket_racing] [ In reply to ]
Quote | Reply
Rocket_racing wrote:
ericMPro wrote:
not sure why they changed.

For me, there's a small bit of difference at low yaw between high stack and low stack (lower is better) but a big difference at high yaw (lower is better). For Kona, I'd go with my lowest position possible... average yaw of 15 degrees this year.

Eric

Who measured the 15 degree average yaw at kona this year? Interesting to see another “typical” windy kona. Shivs and ia’s would be loving it.

Shivs and IAs would still be slower than a low yaw P4. The correct bike is the Trek Speed Concept. I referenced Best Bike Split advanced weather yaw computation.

Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [ericMPro] [ In reply to ]
Quote | Reply
ericMPro wrote:
Rocket_racing wrote:
ericMPro wrote:
not sure why they changed.

For me, there's a small bit of difference at low yaw between high stack and low stack (lower is better) but a big difference at high yaw (lower is better). For Kona, I'd go with my lowest position possible... average yaw of 15 degrees this year.

Eric


Who measured the 15 degree average yaw at kona this year? Interesting to see another “typical” windy kona. Shivs and ia’s would be loving it.


Shivs and IAs would still be slower than a low yaw P4. The correct bike is the Trek Speed Concept. I referenced Best Bike Split advanced weather yaw computation.

Hence TO’s 2nd place finish. 😜

Let food be thy medicine...
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [Pyrenean Wolf] [ In reply to ]
Quote | Reply
Pyrenean Wolf wrote:

Yes it is interesting.

Reed move up slightly
Amberger move up more significantly
Wurf came back to its "pre- Kona 2018" stack, about 3 or 4 cm higher

If aero losses, specifically at yaw (indeed typically the case in Kona) are on one side of the balance, what is/are the gains ?

Muscles efficiency on the bike ?
Preparing a better run ?

- Bike leg side :
Alex Dowsett, ex- hour record holder, 5th this year in the TT worlds, 6 time UK TT champs, was already quite high (10 or 11cm drop for 182cm heigh) and is not going down, seems to me this year he increased slightly his stack to a less than 10cm drop, clearly saying "lower is slower" :
https://www.instagram.com/p/BzSc3nMl2Vh/

Spoiler alert : he is not running after TT :-)
Clearly he identify some interest on the bike leg. Ok, only 1h bike leg, at FTP.
Apparently, at FTP or higher, it is more efficient for him to stay relatively high (for a pro). Muscle efficiency gain > Aero loss ?

- Run leg side :
Any evidence that opening the hip angle in the bike save muscles for the run (gluten, hamstring, quads) ?
Yes. Contrary to some opinions on here, aero is not the be all and end all. Apparently Dowsett lost more power than he made in aero gains when his position was lower.

I would not be surprised if Wurf raised his position to take some strain away from the hip flexors and aductors to avoid cramping on the run. It can also have to do with the length of race, riders in the past such as Cancellara used to have a position for short TTs like prologues, and another for longer TT's of around an hour. Both would be based on how long the rider can efficiently lay down power for the length of the race in question.
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [42x16ss] [ In reply to ]
Quote | Reply
I agree
I was lower on IP and TP (2 to 3km) than in TT (25km).

I'm surprised there is no more answers on the hip angle influence on run efficiency.
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes : improved bike and improved run ? [Pyrenean Wolf] [ In reply to ]
Quote | Reply
Pyrenean Wolf wrote:
Side note 1 : increase stack heigh can bring aero penalty but facilitate power production, so little impact on bike leg ?


Is it possible increased stack help the run, facilitate bike power production, with no/little aero loss (if well studied) ?

We've tested people who have gone higher and gotten more aerodynamic or who saw very, very little drag increase by moving up a bit.

I'd also not discount all that running. Run fitness is the hardest to build, takes the longest time. I'd suspect the real dividends pay off in the 2020 early to mid season.

Brian Stover USAT LII
Accelerate3 Coaching
Insta

Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [Pyrenean Wolf] [ In reply to ]
Quote | Reply
one point of order to this, i think what also matters is where you're measuring elevation to (on the pad) and the angle of the aerobars. for most folks, the elbow sits behind the fulcrum around which the aerobars rotate, and the elbow sits even further back, behind the pad. if you simply rotated your aerobars, extensions high, hands high, most folks would need to place extra pedestals under the pads just to keep the back angle, hip angle, the same as before you rotated the bars. hands-high is becoming a thing with a lot of riders, and hands-high requires normalizing to preserve the other body angles. i have no idea what the riders to whom you refer might have changed their positions. just pointing out that if it's hip angle, and back angle, that you're interested in, pad elevation + aerobar rotation is what goes into that.

Dan Empfield
aka Slowman
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes : improved bike and improved run ? [Pyrenean Wolf] [ In reply to ]
Quote | Reply
Pyrenean Wolf wrote:
1) From 2018 pre-Kona wind tunnel, Cam Wurf tested several configs and choose a config "low stack" may be more aero, more adapted to optimizing bike leg.


For what it’s worth he stated in a recent interview he doesn’t go to the wind tunnel.

My guess is they may implement a beefed-up version of the Chung method which in my mind makes a lot of sense. This is entirely speculation on my part but testing at real world yaws while pedaling seems to be more effective than a tunnel or velodrome.

-------------------
Madison photographer Timothy Hughes | Instagram
Last edited by: Timtek: Oct 30, 19 9:51
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes : improved bike and improved run ? [Timtek] [ In reply to ]
Quote | Reply
Timtek wrote:
Pyrenean Wolf wrote:
1) From 2018 pre-Kona wind tunnel, Cam Wurf tested several configs and choose a config "low stack" may be more aero, more adapted to optimizing bike leg.


For what it’s worth he stated in a recent interview he doesn’t go to the wind tunnel.

My guess is they may implement a beefed-up version of the Chung method which in my mind makes a lot of sense. This is entirely speculation on my part but testing at real world yaws while pedaling seems to be more effective than a tunnel or velodrome.

Maybe he didn't go to wind tunnel in 2019. Not seen any pictures indeed.

But in 2018 he was in wind tunnel just before Kona, with the new Pinarello TR+ disk. I have some nice pictures from this session, they are easy to find. For exemple :
https://lumina-magazine.com/archives/9914

SCx measured and annouced : 0,214

Before this wind tunnel session, he was using "old" Bolide, with "high" stack (see Roth pictures).
After receiving the new Bolide TR+ disk, and the pre-kona 2018 wind tunnel session, he was going "low" stack, as proven by Kona 2018 and Daytona 2018 pictures.

Then, during winter, he went back to "high" stack, as proven by many training pictures (with both old and new Bolide), and he kept this config for Cannes, Roth, Italy (new "black" TR+ with new integrated cockpit) and Kona 2019.
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes : improved bike and improved run ? [Pyrenean Wolf] [ In reply to ]
Quote | Reply
Interesting Amberger went higher around the same time he spent time training with Wurf in Andorra. Wurf benefits from swimming with Amberger, and Amberger benefits from the knowledge and tech Wurf and his team bring...
Quote Reply
Re: Cameron Wurf, Josh Amberger and Tim Reed bike position changes [Slowman] [ In reply to ]
Quote | Reply
Understood.

In Cam Wurf and Josh Amberger case, there is no variation of aerobar angle, just more stack, and the elbow move up the same amount.

Then, I do not know what proportion of this additional stack goes to increase of hip angle, and what proportion goes to more "turtle effect" (head lowering compared to shoulders).

Seems to me it mostly increase hip angle. To increase bike efficiency and/or run efficiency ?
Quote Reply