I bought my 56cm bike about 2 years ago, and have just concluded I bought one size too large, and should have bought a 54. I had a fit done at the time, and they said everything looks good, but I've since tried to shrink the bike. I went from 100mm to a 90mm stem and went from a setback to a 0-setback seatpost. Everything feels pretty good now.

My question is, at this point is there any reason to go down a frame size? Or if everything feels good, just shut up and ride? I don't race, and mostly do gran fondos, centuries, group rides, and commute.

Hopefully you didn't move your saddle forward to get closer to the bars. That is a no-no. If when the saddle is where your pedaling function preferences say it ought to be (that is a primary independent position factor), and the 90mm stem is still too long, I would say you should size down.

It would surely not be too expensive to pick up a 54 cm frame and just move all your parts over to it. Frames are easier to buy and sell than bike, because they are so much simpler. Less details for the buyer (including you) to disapprove of. You could get on ebay and pick up something used. Maybe even an upgrade over what you have now. The deals are great. Or a no-name carbon frame for a few hundred bucks. Much cheaper than a new bike, even probably if you could sell your old one.

But be sure you want a 54. Is a pro fit in order?

I actually put the new seatpost on before I replaced the stem. I had a fitting when I bought the bike, and I feel like everything was set up too big.

I'll poke around for used frames.

How about compact/short reach handlebars? That has helped me keep the seat where it should be and moved the shifters back another 15mm

If you are young and fit and don't care and don't have knee problem, by all means, move the saddle forward on a 0-setback post. But for me, I can move everything except the saddle to bottom bracket distance; otherwise, I am in a world of knee pain.

That is a good trick, since reach to the bar tops is usually not the problem. Unfortunately a short reach bar is where most people start out these days. There isn't much improvement that can be made to that.

Even if it seems O-K now, a 54 will seem a lot better! Nothing worse than a too-big frame! From the very first time you sit on that 54, you will say "AHhhh!!!".

I went through this exact same scenario earlier this year. I returned to riding after many years off. The last frame I had some years ago was a 56cm lemonde zurich. That bike seemed to fit and ride very well. I am 5'9" with a 31.75 cycling inseam.

So, when I started back up again I bought a used 56 carbon no name job from ebay for $700. Right from the start, it didn't feel right. It made my neck hurt, my knees, etc etc. I did everything I could to make it work. Went from a 100 to 70mm stem. Replaced the long reach bars with compacts. Moved the saddle as far forward as was reasonable. It was better, but still not really "right". The handling felt a little off and I always felt like I was being swallowed up in the cockpit. Maybe 10+ years ago my body could have adapted and not complained so much.

I finally gave up and I now own a pair of 54cm bikes. One in titanium and one in carbon. They both fit so much better and I can ride longer than 45 minutes without getting annoyed and achey. The 56cm frame now sits bare upon my wall.

Funny you fit the 56cm Lemond which is probably closer to a 57/58 in today's frame. I would say the loss of flexibility as we age is probably the cause of you not fitting a 56cm frame anymore, listening to your body is definitely a wise thing to do

I did the same. A warr. replacement frame was ~1.5 cm longer in the top tube. I dropped to a 90mm stem and ordered bars that were 8-9mm shorter in reach. I think it would have worked, but I found a deal on a better fitting bike.

+2 (or whatever) on not solving reach issues by moving the saddle forward.

The first road bike I got a few years back was a 56 (57cm top tube) and I always felt too stretched out. I later got a 54 Cannondale CAAD9 (54.5 top tube) which fit ok but ultimately I felt a little cramped even with 120 mm stem. Now I'm riding a Giant TCR M/L (57 cm top tube)with 100mm stem and it feels perfect.

My main point is different bikes fit different. A 56 is not a 56 for every make and model so you really need to get professionally fit (which you did) and get familiar with geometry measurements of specific frames you are looking at. I have had two bike with the same exact effective top tube and one felt huge and the other feels close to perfect but what I've learned is they have different angles and the head tube height is dramatically different between the two. So there are many factors in fitting a bike. If you got on the same exact bike you own now in a 54 that might force you to move the saddle back and that might effect where you are over the pedals and maybe that is why the fitter decided the 56 was a better fit.