Bike Fit... sweet spot or ever evolving? (Page 4)

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Hmm, I was just going by Coggan/Allen's book... an Olympic bike leg you are usually shooting for 95-100% ftp. Although my question would translate to whatever "guide" you were using for pacing. 10% more AVG watts, NP (which basically is IF anyways) or whatever.

you could probably ride close to 1.1 if you were using your FTP estimate (and had no intention of running afterwards )

ahh I see what you're saying, although the question of translation comes into play. I do all my ftp tests on my road bike, and then use the zones/pacing for road AND tri bike. I haven't ran into a problem yet where I needed more power for my tri's (that is to say, IF I could make more power, it wouldn't be doing me any favors in relation to what we think we know about not burning up on the bike and walking/jogging the run...although I admit I'm not by any stretch of the imagination an expert on such things.)

It is tougher to ride crunched down (my position) at FTP for 10+ minutes. It's not tougher to ride below FTP (reasonably below) for 50+ miles (other than the next morning haha)

I should do an FTP test on my Tri bike just to see what the drop off is... I really hate doing FTP tests though

So I guess I'm saying I don't know... does anyone know if I can drill/tap into a Shimano crankarm? Or is it actually "hollow"

It also likely has to do with what software you're using. The Olympic from the picture above I had an IF of 1.04

However WKO estimates FTP MUCH closer to real hour power than most FTP tests do. So YMMV

Hey Tom

Do you believe such a small drop in bars would have that big an impact on power generated ?

^ Poweragent, sorry.

(To expand on what I meant, My 20' Power is 307 - Coggan/Allen test - so FTP is estimated closer to 29x, but Poweragent measures 4' & 30' power to get an estimate. That # usually ends up closer to TRUE hour power in my experience... but that number is likely not accurate either... hard to know since I've never done a true 1hr test)

Poweragent assumes my FTP is much closer to 240, so it's easier to see how I could ride a 1.04 If my true FTP is somewhere in between or closer to the Coggan/Allen method.

Triathlon... the sport where the more sh*t you buy, the more confusing life gets

Edited by Leegoocrap 2013-10-07 12:58 PM

Do you test in that super aggressive position for the full 20' ?

True or false, in your opinion:

"95% of people can fit 95% of bikes"
(This is something that a respected bike fitter in my area said to me once).

I think there's a segment of the tri/cyclist population that believes in the "one true bike fit"-- that for any individual, there are only one or two frames that are optimal for their body type. The quote above would suggest otherwise.

While there might be certain people who are better suited to one particular geometry, or, more likely, that a particular brand of frame is poorly-suited to their body, my anecdotal opinion is that it seems like most people can get a nearly-perfect fit on just about any model, assuming it's the right size.

And to the extent that bike fit is constantly evolving and that there isn't really ever a "perfect" fit, that means that there's nothing wrong with, for example, choosing a frame based on the color or the component group.

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You're right of course, it would be better to do on my tri bike in regards for this scenario (this thread particularly) but I do want the highest numbers in the test so I can zone "optimally." Ideally I'd test for each bike separately, but realistically that's a bit more mentally taxing than I'm up for.

As I said above, I've held 10' sets at ftp (and a bit higher) in aero... but have never buckled down for the full 20min.

If you're willing to compare an inside trainer FTP test to an open road TT (actually closer to 25 minutes) held after a road race (which is obviously flawed in numerous ways) then you'd get about 40 watts difference in favor of the road bike on the trainer.

But again, Fred is right... I should test on my tri bike too.

* as for the fits... I think *most* people could fit on *most* bikes they bought in T-shirt sizes (like I couldn't buy a 64cm bike and be ok, but I could probably ride a 50-58 range at least adequately as far as the general population is concerned.) although you'd get some strange setups on the extreme ends.

For example, Fred looks good riding his Shiv. I tried a Shiv at my LBS and had I been interested I'd have needed an XS with a forearm length stem to get near my Planet X's position or would have had to settle for a massive gain in Stack and loss in reach... (which if you've been following this thread may have been better )

Edited by Leegoocrap 2013-10-07 3:59 PM

So your 20' test gives 307.

What do you think you could hit on the 20' in that aggressive position under the same conditions (indoors/outdoors) ?



Edited by marcag 2013-10-07 4:16 PM

If I had to guess... just shy of 290w

When I get my P3 built up I'll take the guess work out of it.

You're giving up almost 20watts on a 20' test.

How sure are you that position is the right balance between aero and power ?

I'd say pretty much everyone experiences 2-3% difference between the 2 positions (which is closer to 10 watts in this case)

You asked what I thought I could do, not what I was capable of. Doing a REAL all out 20' test is tougher than (mentally especially) than you seem to be giving it credit for.

There's always room for volunteers. Get on both your bikes, don't sandbag (and don't sit up) and let's see if I'm just a wuss. I think a lot of you guys will be surprised.

Edited by Leegoocrap 2013-10-08 2:46 AM

It's also important (and very difficult) to say whether those watts are limited because
a.) the position is limiting the output (biomechanical)
b.) the lack of time spent attempting to maximize power in the position (specific training) or lack of time in the position as a whole (bike choice) is making the difference.

there's a lot more going on than what makes it a simple "you make less watts for 20' here, your position is the problem." That's what makes it's difficult to make changes and know whether they are better or worse short term.


Edited by Leegoocrap 2013-10-08 5:38 AM

I know. I would bet I have spent as much, if not more time than anyone trying to dial in my position and understand the impact on my power. I've rode steep, slack, shorter cranks....you name it, i've tried it.

Yes, I have been in a tunnel, yes I chung regularly, aerolab....measuring frontal area.....I do it because I find it interesting, not because I obsess over .01 on my cda. I am a data and science geek so I find it interesting.

But I always find a way to do testing while getting my normal workouts done.

I am also a believer that there is a line you cross (on the way down) that you are losing. I have a funny feeling you may be close to that line if you haven't already crossed it. The most dialed in guys in triathlon aren't in a position as aggressive as yours. That intrigues me.

You are right that it's more than "you make less watts for 20' here, your position is the problem."
IF you are producing less watts, you need to figure out the why and whether the less watts is worth the cda saving (if any).

The first thing I posted in this thread was




The blood lactate device is so I don't have to do 20' tests in aero position, because maybe I am a wuss, but I don't like them either.

So to answer the title of the thread I think it's ever evolving and the hoopla of fitters is way overdone. There are a handful of fitters that get the whole picture. You should go visit Mat Steinmetz

That's fair

For a random change of topic... how do the fit systems that measure power (retul maybe?) work? Do they just measure "current" power? Avg? Over what course of time?

It's worth mentioning my next position is unlikely to be *as* low as the current one (although still pretty low to compensate somewhat for the high hands) This is more what I'm testing next...





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Chris,

As evidence for me that I was heading in the wrong direction with going low was that the discrepancy between my road bike 60' FTP and tri bike was pretty large at 30 to 35 watts at one point.... 325 to 295, that was last spring. I had gotten low on my previous bike (there was a 5.25" of saddle to pad top drop, now it's at 4") and while I had decent short duration numbers that matched my road bike for the 1 minute, 5 minute and 10 minute tests... it's that I my watts would precipitously decline for longer term segments b/c my hip flexor would burn like a mofo at the tight angle. Further evidence, is that after being squished up for the time of like Oly length events or longer, I wasn't negative splitting, but losing about 5 to 10% over the race. Another thing was that my right hamstring where I have lower back tissue damage from previous weight lifting injuries (in my 20's) felt like it was being ripped off the bone after an hour and had to deal with the pain or back off the watts.

Anyways, not an advertisement for the SHIV, but when I couldn't place my bars as low as the previous bike and reset my fit... 2 weeks later and the absolute first ride with the bike, I won my first HIM triathlon with best bike split at the lowest effort that I've had at that race before and it set me up for a run that got me home in time for the win. Then I blew away my power numbers at the state TT championships, and then did a great split the next week for the Oly. That being said... I'm happy, my position is less aggressive and my power production is now almost in line with the road bike.

If I made any changes to my setup, it would be to experiment with 165mm crank from the 170mm during the offseason.

I get the impression that you're in doubt, or insistant about being as low as possible... there are some of us that think that maybe you've gotten too far... I understand the dilemna in your mind... I doubted the evidence and advice too, perhaps you'll have to convince yourself during the process of discovery. I think that it's hard to look at TT specialists and think that you can do that too... ALL of those folks that you look at don't have to run afterwards and probably have more miles experience than all of us combined.... plus they have a team of professional advisors, coaches and trainers to look over their shoulder. Keep that in mind.

You have to answer your own question, are you trying to be a TT specialist or triathlete?

I asked before in this thread, what are your definable goals? I know what mine are and I set them back 2 years ago and am finally closer to them than ever before and will have to reset them soon for next year.

Edited by tomspharmacy 2013-10-08 9:41 AM

To push and find those limits. You think I'm past there, I think I'm not. Neither of us has evidence to prove we're right other than n=1.

If we don't go too far, we won't ever know where those limits are.

For my own n=1, I changed my position (to the one above) and set pr's in every distance I raced this year, bike and run and included a few pure Time Trials.
That doesn't make me right though, and now we're in the most dangerous territory of all, using uncontrolled results as verification.

Edited by Leegoocrap 2013-10-08 9:44 AM

Good, sounds great...but how do you know that those results aren't a result of improved fitness vs. proper position?

We've got you in the witness stand... LOL