Bike Fit Critique and Sizing Question

I have the same bike, in a 48cm. 

You look stretched out in the upper body, like you're reaching.  Beyond that, I can't offer anything.

Another peanut gallery comment, ie you should ask a good fitter

Yes, you seem a little stretched in front. But you also seem to be riding quite back (slack), so there is an opportunity for the seat to go forward. If so, you can also go down a bit and maintain the same hip angles and your back would be lower

You may find it tougher on the neck, but there is only one way to find out

So I would not jump to the conclusion of too much bike quite yet.

Couple questions....

What size stem do you have on now?  How adjustable are your aerobars?  How far forward (degrees) is your seat?

These questions will be a good indication if you have room enough to make adjustments or if you are at the limit and need to downsize.  

I agree with marcag said.

What is your stem size? Can you move your seat fwd? Make sure you mark where you are now in case you mess up everything lol

This reminds me, when I was fitted on my (same) bike, I needed more adjustment on the aero bars so I wasn't as stretched out.  I switched from the stock bars to Profile T2+ bars so I had the ability to bring them towards me a little.  It made a world of difference for me.

This thread got me thinking, has anyone tried using this:

http://blog.ubersense.com/2012/08/09/triathlon-bike-fit-introduction/

I haven't tried this one but use proviewer.  It uploads video and then you can pause it and check an angle.  It's not perfect or the same as a fitter but can help tweak things or fix really bad fit.  

A couple thoughts.  You might be "in between clubs" with the two bike, so both might fit you.

I like the calculator on competitivecyclist.com .  They offer a range of top tube dimensions that they feel would work for you and both bikes might fit in that range.  After that, it's just setting up the rest of the bike.

I found that my professional fittings fall within mm of what competitivecyclist give me.  In fact, if I lose some of my setup due to new parts or if I had to take the bike apart to ship, I go back to that calculator to get it set up right again.

I think most people can fit pretty well about two different frame sizes.  Rare is someone that would fit a 52cm EXACTLY where a 50 is too small and the 54 is too big.  Many pros also go with a slightly small frame as they then to be a bit lighter and stiffer because of the marginally smaller tube lengths.

I'll have to check it out. It's got to be better than paying $200 for a fit on a $700 bike!

Generally speaking, I'd be surprised that someone your size got put on a 51.  

That said, if it feels good - why question it?  Maybe you're more flexible and can get into the position and it's no big deal?  I just don't understand why you're questioning it, based on what you wrote.

This ^ 

I have no qualifications other than my own fitting experiences.  But, I think you look fine on the 51.  I think the fitter probably put you on the 51 to avoid using a ton of spacers on the 48 because you don't seem to have much of a drop from seat height to armrest pad height.  It looks like you have a good angle upon leg extension.  Your knee and foot perfectly align, so I wouldn't move your seat forward one bit.  As for the reach, it doesn't look out of wack at all.  Your elbows are aligned pretty well with your ears.  But not everyone is comfortable that extended, even though it's not out of the ordinary.  It's a little bit personal preference there IMO.  If you're not compfortable I would look at moving elbow pads back a touch

I agree, there is a lot of flex going on in the basebar or something.

Also, agree with this.  I'm actually surprised someone your size would have any spacers at all on a 51.  I would think you might need some spacers with a 48 (built up on the larger end of the spectrum - longer stem, more spacers, etc) or no spacers with a 51 (built up on the small end of the spectrum - shorter stem, no/fewer spacers). 

I have a 51 P2 (and a 54 R3) and I'm ~ 5' 8 and have one spacer below the stem (100mm).

CJ