OBBB14

Reading and trying to learn - BEFORE - I purchase bike. I'm puzzled when I read that somebody's wife or girlfriend tried the Trek but the Specialized bike fit her like a glove. Or Visa-versa.
Not sure that it applies to all types or bikes as I have been looking first at Comfort and now hybrid might be better for me to grow into as my fitness lets me breathe. ha ha Specialized Ariel or Trek Neko is what is in town here. Trek 7.2 seems similar too.
Have not ridden in forever (no gears, brakes on pedals) so there has been much to learn. No test rides yet, still pondering if I'm getting the right type bike too. Want to drive to BIG CITY so I can try out both bikes at same store. Assume it would be best to stick with the 2 brands carried here in town.
Any input appreciated. for puzzled question and bike types

Kopsis

The short answer is that you can only adjust the saddle and bars by a certain amount before you start running into a variety of problems. In most cases, the range of adjustment is about +/- 1 inch (20 mm) (though saddle height usually has a larger range) before you either hit a physical limit or start to negatively affect the way the bike was designed to handle.

Why different brands fit differently is that bike "sizes" are typically based only on the length of the seat tube (the frame tube that goes "up" from the "bottom bracket" where your pedal arms attach toward the saddle). However that number doesn't tell you anything about how "long" the frame is (distance from the saddle to the handlebars) or how high the front end is (height of the handlebars above or below the saddle). Seat tube and head tube angles and whether measurements are actual or "effective" further compound to make the listed "size" close to meaningless.

For example, two people with the same leg length may not be the same height. Though both would (in theory) need the same length seat tube, a taller person with short legs may want a longer frame than someone who is the opposite. Likewise, a rider with good flexibility may want a frame that can get the bars lower for better aerodynamics while a less flexible rider may need them much higher so the frame's "stack" measurement becomes important.

Experienced riders often know exactly what they need in terms of "fit". Less experienced riders aren't so fortunate. That's why the best thing to do is test ride the bikes you're interested in and pay very close attention to how they feel. This can be difficult because your body can compensate for a lot of fit problems for a short time without you really noticing. So note things that feel even slightly "off" on your test ride since they will probably become major fit issues in the long run. Don't settle for a bike that needs major bar/saddle adjustments until you've tested all your options. Unless you are very uniquely proportioned, chances are at least one brand in the style you're looking at will feel good "right out of the box".

Sticking with locally available brands is convenient if you need warranty service, though most bikes never will. For things not covered by warranty or after the warranty expires, your local bike mechanics should have no problem working on brands other than what their shop sells, so you needn't feel restricted to just two brands. However, most shops will include one or more free tune-ups with the purchase of the bike, so having that service available locally might be reason enough to buy from your local shops.

chaadster

I'm somewhat in awe, Kopsis, that you could say all that without using the word "geometry" even once!

OBBB14

Thank you - understood

RoadTire 

Good catch.

squatchy

All of what Kopsis said is right on.

I can add a little bit from my experience. I own several bikes. I paid for a professional fit and it worked for me. I have been able to make my same measurements on every bike I won. All the way from a 58 to a 63. Even though All bikes are set up with the same measurements by changing stems and a higher or lower amount of saddle post exposed I can tell that some are a better fit than some of the others.

For instance I have a 58 S-Works Roubaix and a 61 S-Works Tarmac. Both have pretty much all the same name brand componenets. And the difference is risa and reach dimensions. I bought the Roubaix first and really liked it. I have recently decided to selll the Roubaix because I just feel better on my Tarmac. I'm not talking about quality of ride. Most of that comes from your wheelset and tires/tubes.

I also own a 60 Tommasini and a 63 Eddy Merckx. Again they are set up with the same dimensions but each feel a bit different. The differences there are probably more the tubes that were used to build the frame. Both of them are truly superb rides in every way. Just a bit different.

My SO rides a 56 Roubaix. I just recently bought her a Lemond Zurich in 54 and made the cockpit dimensions the same as her Roubaix. I built one of her bikes to climb with and the other to ride fast on the flats so the drivetrain is much different. She doesn't get caught up in bikes like I do but she has noticed a few of the differences one would expect to feel in regards to the ride qualities of steel verses carbon. She also noticed the difference when I bought her her first set of really nice wheelset and could tell some of the difference in tires as I have fished around some to learn for myself what the differences are between width/depth and rubber properties.

I guess my point is that many bikes can be made to fit. Like someone above has said. Just go ride some and one will tell you to take it home. I have heard before somewhere that your firts real keeper is probably your second bike you end up purchasing. Personally I started out with top shelf modern bikes and found that for me, the top shelf steel bikes of earlier years are much more appealing. I feel like my steel bikes have a personality and have become my friends. My carbon bikes just feel like lifeless machines.

That is probably not so unusual for me as I also flyfish and bowhunt with traditional gear. Meaning I am drawn somehow to a different era.

Make sure to post some pics of your new ride when you get one

fietsbob

Bring a tape measure and compare the data..