New tri bike & lower power output
I just purchased a new Tri bike (6 weeks into OS) - Cervelo P2 - I was riding a Cervelo Soloist (road/tri) that was setup with aero bars and rotated seat stem. The P2 was purchased/setup @ local tri store by what I believe to be competent tri guys. I read the EN e-bikefit book and my setup looks about right. My position on P2 is more aggressive (lower torso position) than the old bike setup. I use a computrainer in my pain cave and spend my time racing the terminator. On my first couple P2 workouts I'm noticing I can't stay in the aero position and maintain the same power output as my old bike. If I sit up I get close to old power output but have to fight to beat terminator. On the old bike I felt like I was making FTP progress as I was beating terminator by larger margins as the weeks progressed. I feel my CT setup is consistent and I calibrate before/during each session. I spoke with my P2 setup guy and he claims the new position will be less effecient power wise but faster due to lower drag when I get outside. Not sue I totally buy that but?
Is my setup guy blowing smoke up my ...?
With new FTP testing coming in a week - should just accept a same/lower FTP on the P2 or switch back to old bike to measure any true gains?
Any other insights?
Comments
How much of change is it? Do you know what your saddle to elbow pad drop is on the old bike vs the new one? Can you post before and after pictures?
What Matt said. It's a very fine line to walk b/t maximal power output & aerodynamic efficiency, while also trying to save your run legs.
As a quick example, I ride pretty steep with a good amount of drop. Right now I am able to consistenly put out about 215w in aero position indoors. That's a position with pretty small frontal that will ride well outdoors & my legs feel quite good to run after. But if I sit up in the pursuits I am able to hold 235-245w pretty easily. My run legs would be fried if I stayed upright though, and my aero profile would suck. It's also alot easier to me to unweight the pedals & push out a solid circle when upright versus aero.
So it's always a tradeoff & you have to navigate that line with what works best for you.
My setup guy did tell me the new position would yield better run results - on my saturday brick the transition was pretty easy.
Even with a good fit, you'll probably have a little lower power than on the Soloist. With a really crummy one, it could be worse.
Anyway, there have been several threads around here about "are you doing your OS on road/tri bike?" or "are you doing your FTP work in aero position?" etc. The short answer is that different people have come to different conclusions and I don't think that a clear "best" answer is out there yet. On the one hand is the crowd that thinks that it's best to get as strong as possible, so they do the road position training. Most of them will have exactly the same phenomenon as you - lower power when they hit the aero position, but they will tell you that (a) they are faster anyway in the aero position with fewer watts and (b) They make some of the difference back up in a few weeks as the specific muscles get trained up. In the other camp is the crowd that does most of the FTP work in aero position, basically for reasons of specificity and to avoid that secondary train-up period. To repeat myself, it's not clear to me that there is a "right" answer on this.
My notes:
i trained in aero exclusively for IMAZ 2010. my starting FT was 180 NP vs. 265 NP sitting up going into 2009IMAZ the prior year.
played around a lot with position, eventually got a pro fitting, and arrived to IMAZ with a 216-220FT.
result:
2009 bike split: 6:10:06; slow run; rode a lot out of aero in the final lap.
2010 bike split: 6:01:33 & fast run. was aero 99%.
conclusion:
i found that the predicted EN pacing translates best on race day, when you do the same as those whose numbers were used to build the database. this is likely testing sitting up mostly and then transferring over to aero work in the race prep period. this normalizes out to a strong bike and strong run, if you ride 68-72% of the sitting up FT.
2weeks from IMAZ, i did the FT test on the P3C, but sitting up and got 232 NP.
just got a road bike and have been riding up at the 300watt range for longer than ever before. my next FT test will be on the road bike. However, despite the ability to generate higher numbers on the road bike, i still go a lot faster on avg on the tri bike.
this OS, i am super excited to ride the road bike to build my power. occasionally, i'll ride the TRI bike, just to keep myself used to the aero position. otherwise, the pipeline is set for us with the current EN pacing tables.
i hope this adds to what the others have advised.
P.S. the above applies to most of us. of course, eventually you get good enough to have similar power outputs for whatever position you are using. these are the ENers of GA'Hoole types
sorry guys, i just re-read the post and lots of things were not clear (wrote too fast!). hope it's understandable.
anyway, meant to say 2weeks out from 2010 IMAZ my FTP was/is 232.
also, i am comparing 2010 and 2009 IMAZ races in the text.
finally forgot to mention that the weather (rain and wind) were polar opposites in 2009 (perfect weather) and 2010 (bad).
GH
here's the arithmetic for the experiment i poorly articulated previously:
pure aero determined FT for IMAZ2010: 224 (i double checked my IMAZ aero FT and it was 224);
70% of this = 156.8 goal watts;
10days after the race my sitting up FT was 232;
70% of this = 162.4 goal watts;
key rides before the race indicated that 70% of 232 was about where i was supposed to be. so, it got confusing as the race approached, since i wasn't sure which way to go. 156.8 goal watts seemed too low in training.
in the end, i ended up boogering the ride and raced the bike leg at a puny 144NP!
with more confidence i could have done 162, all my rides before that indicated so, i just got pysched out. live and learn.
So, as the others recommend:
-build FT on the new bike or road bike;
-don't worry about losing power while in aero position, but do work to get comfortable in that position;
-base your IM or HIM pace based on the sitting up FT's and it will work out on race day, unless you booger it like i did!!!
GH
Ltr P2 Soloist
A: 30.125 31
12.875 12.5
B: +.375 -1.5
C: 30.125 28.625
E: 3 1.5
F: 17.25 17
G: 7.75 10.625
All dimensions = inches
some answers to above questions/comments
- come spring I will purchase a PT. I chose CT specifically for spin scan function - for bike intervals I view split screen and monitor rpm/watts/NP on one side and spin scan on other side - I'm new to cycling and find spin scan keeps me informed on pedaling efficiency - especially towards end of longer intervals as my legs begin to tire
- My old bike was setup as a tribike- aero bars & rotated seat post for steeper angle
- Up till last week (old bike) all work/tests done in aero position - on new bike I'm splitting time - down as long as i can then up - my body seems to be adjusting slowly though
- looking at the measurements above - i notice my aero pads are closer together - maybe restricting airflow to lungs - also new position is a little lower-probably impacting leg power
I've been drinking the EN Koolaid and think i'm making progress
Thx for the all input
I'm guessing the new position is putting more stress on different muscles in your legs such as the hip flexors. Give it a little time as the 1.5 inch drop should make a noticable differance in your speed on the road.
My elbow pads are at 17.5 cm apart which is almost 2 cm or an inch closer together than yours, so I don't think you are restricting airflow by a significant amount. Of course you had the pads much wider on the other bike so it proably feels a little different now but you should adjust to that as well.
BTW, great job getting all the fit cooridinates but everything is usually measured in metric units as all frame sizing, stack and reach, stem sizes, etc are metric. If you have your all of this in metric it is easy to change bikes and keep the same fit.