hi i'm fairly new to road cycling. i noticed that the saddle height/seat post is raised fairly high for most advanced and pro riders. i would assume that would make the reach to the handlebars further away. to compensate, would you ride a smaller frame and raise the saddle height?

for example, if someone was fitted on a 51 (53 effective tt) with a relatively low/normal saddle height. would they size down to a 48 (52 effective tt) and raise the saddle height higher? i didn't really know how to phrase the inquiry, sorry if this is a stupid question.

https://www.sheldonbrown.com/frame-sizing.html

That Sheldon Brown article is a great start. In general, my theory goes that you just need to keep tweaking things until it feels right to you.

Going down to a smaller frame to raise your saddle seems like it wouldn't be comfortable. I like my saddle high and my drops low because I feel like I can stretch out a bit when I go to my drops and I like that. If you go for a smaller frame size your arms will always feel too cramped IMO.

Just make sure you don't raise your saddle too high or you'll end up with Achilles tendon problems.

Yep, as the frame gets smaller, the seat tube (and just about everything else) shrinks. Your saddle height is really non-negotiable, it needs to be a particular height for your legs. So if they get a small frame, the saddle goes up. You're right also, that the drop increases. The head tubes are shorter on smaller bikes too, which means the handle bars are lower. They'll often put a longer stem on to compensate for horizontal reach, but you need to be pretty flexible to do this because as you said, the saddle to bar drop increases as well.

You can get around the saddle-bar drop increase by using a positive angle stem, but that isn't very pro looking so you don't see it much on pro bikes.

As someone who just sold a 60cm bike with more relaxed geometry to a 58cm with aggressive race geometry, I can tell you the smaller frame definitely handles better, and is a bit lighter. This is why they size down the frames.

Particularly true for mountain bikes. I've gone down a size or two (29er) from the charts and you get a lighter more nimble bike. Of course, you end up with 7 inches of seatpost to the saddle, and risers bars.

The pros (to me pro= anyone that gets paid to ride, or perhaps anyone that races and wins enough for the $$ to justify it) may use the tactic of buying smaller frames to increase the amount of drop from saddle to stem height, which does as others have said necessitate using longer stems. For the rest of us, buy the frame that is the right size, then tweak it to fit you: longer stem for more reach and to be a little more stretched out, get the right saddle height for proper leg extension, etc.

On a related question, how long can a person go on the stem length? On my old road bike I was afraid about getting a stem that was too long and might end up putting my hands too far out over, and possibly in front of, the front hub. I was afraid that doing so might make riding the bike a little unstable from putting too much weight out over the front of the bike. Everyone, is this a misconception?