Road Bike Racing - Standard bike fit Vs. Bike fit with Power

Hi guys,

I haven't had a bike fit on my current bike. I just guesstimated everything and raced on it last year. I'm thinking about getting a bike fit and am planning on working with a very reputable fitter here in Austin. He offers two options - 1. standard bike fit which takes about 30 minutes for $50 or 2. Bike fit to optimize wattage/position that takes about 2.5 hours for $150.

Does anyone here have any experience using power output to optimize your bike fit? Is this kind of thing worthwhile?

-s

I haven't done it, but I think it's worth the extra $100. $150 is a good price. I would have expected $200.

I'm self-fit, but when I get a PT this Christmas, I will revisit my fit with power data.

The thing is, I think your power may not adapt to a given position until several weeks of riding in it, so positions closer to your current position may appear skewed to favorable in the shop fit, because of this adaptation.

So, I think tracking your power over time would be useful when changing positions. The shop fit should be a good first stab though, and much better with power input, I think.

Hi guys,

I haven't had a bike fit on my current bike. I just guesstimated everything and raced on it last year. I'm thinking about getting a bike fit and am planning on working with a very reputable fitter here in Austin. He offers two options - 1. standard bike fit which takes about 30 minutes for $50 or 2. Bike fit to optimize wattage/position that takes about 2.5 hours for $150.

Does anyone here have any experience using power output to optimize your bike fit? Is this kind of thing worthwhile?

-s

What do they do that merits $ 50 for 30 mins? Sounds like you're paying them to sell you a bike?? What do they do in the 2.5 hour power-based fit session?? How do they test the power-based fit in real world conditions (i.e., on the road in the wind)?

gene r

You can't use wattage to get fit. You have to adapt to the position before you know what your power is gonna be with the new position.

Don't waste your money on a power fit. Spend your money on making sure you have a good fitter -- if you're in Austin, I'd look into Wenger at Source Endurance (http://www.source-e.net), or Sol Frost at Austin Bikes (http://www.austinbikes.com). They don't need power to get you fit correctly.

Adaptation is gonna take weeks, so don't bother with a power fit.

Interesting. Makes sense though.

BTW: I'm talking with Sol (hopefully tomorrow morning) about joining a team...

AT&T or Austin Bikes? I vote AT&T!

I agree- don't waste your money on a power fit. It isn't accurate until you have ridden with power for a while and even then, it's not as guaranteed as a "true and tried" fit. I outfitted my cleats with a special plate to move them more in the middle of my shoes and my FTP went up about 7 watts. I will go back to my old set up which I suspect would yield the same average.. sometimes trying something new results in a strong reaction that is not necessarily beneficial in the long run.

AT&T or Austin Bikes? I vote AT&T!

Yeah, I just need to see the M35+ squads. I guess I could race Cat 3 and help push riders up, too. Still, I'm mostly interested in M35+ (faster, shorter races :))

Hi guys,

I haven't had a bike fit on my current bike. I just guesstimated everything and raced on it last year. I'm thinking about getting a bike fit and am planning on working with a very reputable fitter here in Austin. He offers two options - 1. standard bike fit which takes about 30 minutes for $50 or 2. Bike fit to optimize wattage/position that takes about 2.5 hours for $150.

Does anyone here have any experience using power output to optimize your bike fit? Is this kind of thing worthwhile?

-s

I was fit to my current bike over a year ago. Went in for a ramp test on a Computrainer with a coach. We observed the estimated wattage at a certain HR and rpm. Adjusted the height and rails and squeezed out 10 more watts at the same HR rpm. Other posters have said you need to adapt to the position...I agree but an increase due to fit is an increase. What am I missing here?

I was fit to my current bike over a year ago. Went in for a ramp test on a Computrainer with a coach. We observed the estimated wattage at a certain HR and rpm. Adjusted the height and rails and squeezed out 10 more watts at the same HR rpm. Other posters have said you need to adapt to the position...I agree but an increase due to fit is an increase. What am I missing here?

The variability of heartrate. When you do any power:HR ratios or comparisons, you're basically combining a (typically) accurate measurement with an inaccurate one and end up with an inaccurate composite measurement.

Power should be compared to time. That's how it works in races where there's no cap on heart rates but if you need to do X watts for Y time to make a selection, you either do it or get dropped. I've never been to a race where one of the rules was that you had to keep your HR under 170 bpm.

Change your fit and if you can output more power for the same duration then maybe it did something.

The variability of heartrate. When you do any power:HR ratios or comparisons, you're basically combining a (typically) accurate measurement with an inaccurate one and end up with an inaccurate composite measurement.

Power should be compared to time. That's how it works in races where there's no cap on heart rates but if you need to do X watts for Y time to make a selection, you either do it or get dropped. I've never been to a race where one of the rules was that you had to keep your HR under 170 bpm.

Change your fit and if you can output more power for the same duration then maybe it did something.

That makes sense. thx!