I'd be surprised if your new frame is "too large", as I have never seen an experienced adult cyclist riding an expensive bike that was too large. But 60% or 70% of the guys I see on road bikes are riding a frame that is one, two, or even three sizes too small.

There are two measurements that matter in bike fit:

1. Saddle height

2. Cockpit length (the distance from the back edge of the saddle to the front edge of the stem).

A guy doesn't go into a store to buy slacks without knowing his inseam length. And a guy should not buy a bike unless he knows his cockpit length.

Bike fit is really, really simple. If you can dial in your preferred saddle height, and your preferred cockpit length with the bars at your preferred height, the bikes fits. If the bike is set up with your preferred saddle height and preferred bar height, and the cockpit is too long, or too short, the bike does not fit.


Set up your new bike with the saddle at your preferred height, and at the middle of the saddle rails. Raise the bars to the correct height (which ranges from level with the top of the saddle for a long distance cyclist to two inches lower than the top of the saddle for racing crits or time trials).

Then measure the cockpit length. All of my road bikes have precisely the same cockpit length, even though the frame sizes range from size 56 to size 61. How can a size 61 bike have the same cockpit length as a size 56 bike?

Although the top tube on the size 61 bike is longer than on the size 56 bike, the frame is taller, and the headtube is longer and taller. The combination of the taller frame and taller headtube brings the bars both up and back, closer to the saddle.

You can verify that your new frame fits by taking measurements on the bike that fits you the best. Measure the saddle height and the cockpit length. Then set the saddle on your new bike to precisely that height, put the bars at your preferred height, and measure the cockpit length. If the cockpit length is within 1/2 inch of your "perfect" bike, it will be easy to dial in a perfect fit by swapping out the stem.

If the "perfect" cockpit length for you is 31 1/4th inches, any bike that provides you with a cockpit length of 31 1/4th inches is a perfect fit, regardless of the size of the frame, or the length of the top tube.

What about the relationship of the knee to the crank? Many sprinters SWEAR that it is crucial to have the knee in a forward position relative to the crank bolt. And, Greg LeMond SWEARS that having the knee BACK relative to the crank was crucial to his success in long stages and climbing stages. But, for cyclists without a racing license, comfort is more important than mythical claims about racing performance. Start with the saddle at mid-rails and dial in your preferred cockpit length. If you are into short fast rides, you may end up sliding your saddle a bit forward. If you prefer looong rides with a steady high cadence, you may prefer sliding the saddle back a tad.