hello to everyone!

new to this forum [this is my first post] as well as to the cycling community. i'm curious on the frame sizing and what size is adequate for my body height. i'm roughly 5'8. any and all feedback is greatly appreciated [i apologize if i'm posting this question in the wrong part of the forum]. again, great to meet you all.

kind regards,
garrett

I bet you'll like a 52 or 53cm. Something with a 54cm toptube. Have fun.:thumbsup:

Bike sizing is a lot more complex than just overall height. There are some helpful fit calculators on line, but you'll do best if a qualified person at a local bike shop (LBS) can measure you and put you on a few frames and watch you pedal.

Depending on the manufacturer, you could wind up on something as small as a 52cm and as large as a 56cm, with the most likely scenario somewhere in between. But even after you get the right frame, you'll want assistance being sure you get the saddle position right (both height and fore-aft) and stem length (reach to handlebars). In short, no one can really nail it down for you via the 'net.

The numbers are the nominal seat tube height. But the top tube length and the frame angles determine the reach to the bars, which is just as important. Some bikes are built long, others short. You can use a short or long stem to compensate but the handling gets wierd with very short or very long stems. The seat tube height is measured differently on different bikes. One manufacturer's 54cm will be different from anothers'.

I have gotten some crazy numbers from the more well known online fit calculators, so don't take them as pure gospel.

thank you all for your feedback. being a novice and new to cycling, i don't know everything yet and i'm glad i asked. i really appreciate you all taking the time to steer me in the right direction and i'll go to a local shop to get a better idea of all the specifics.

regards,
garrett

Not to change topics here but..........

Don't hesitate to ask forum members about their favorite shop in your area. There is a lot of experience here.

Also, I would visit as many shops as possible to find not only a good bike fit, but a good shop fit, i.e., one where you feel comfortable and one that understands your needs and doesn't just try to sell you the most expensive item in the shop.

Measure your inseam: stand against a wall with your feet 6 inches/15 cm apart, no shoes. Push the spine of a 1 inch/2-3 cm thick book into your crotch with significant pressure, and measure the distance from the book spine to the floor. Your saddle top to pedal axle should be 108-110% of the inseam measurement.

Here are several frame fit calculators.

http://www.zinncycles.com/fitsystems/default_ie.aspx
http://www.bsn.com/cycling/ergobike.html
http://www.coloradocyclist.com/BikeFit/index.cfm
http://www.sheldonbrown.com/harart-frames.html
http://www.rivendellbicycles.com/frameinfo/Frame_Sizing.htm
http://www.peterwhitecycles.com/fitting.htm
http://www.wrenchscience.com

For adjusting the fit of the bike, there are roughly five starting points:
1. Seat height (top of saddle to center of pedal axle) at 108-110% of inseam.
2. Saddle parallel to ground.
3. Saddle fore/aft adjusted so that a plumb bob from the bony protrusion just below the kneecap passes through the pedal axle when the cranks are horizontal. This is known as KOPS (Knee Over Pedal Spindle)
4. Front hub axle obscured by the handlebars when riding in your "regular" position (drops, hoods, or tops).
5. Top of handlebars 1 to 4.5+ inches below the top of the saddle depending on your flexibility and size.

These are all starting points for "average" proportioned people, and many folks like to move away from these starting points as they learn what makes them more comfortable, powerful, or efficient. For example, the KOPS position range is typically +1 to -2 cm, depending both on your personal physiology (long femurs tend to push the saddle back) and pedaling style (spinners move the saddle forward, pushers move the saddle back). You want to get the fit of the frame as close as you can, then do minor adjustments with the stem, seat post, saddle position, etc.

A lot of this is personal comfort, and we all tend to adapt to a given position over time. For example, a given stem length may be right for you, but it may feel long at first. I use the "handle bar obscures the front hub" rule for my fit, but others claim better position (for them) with the hub in front of or behind the bar. Plus, if you look down without moving your head, you get a very different view than if you tilt your head to look at the front hub. I'm 6' tall and ride with 11.5 cm drop from saddle to bar, probably more than most people would like but fine for me. Some are suggesting zero drop from saddle to bars - it's about comfort, efficiency, and aerodynamics. No calculator is infallible, so look at the different results you get to see where there is consensus among them. I would suggest riding some miles (over 100 total, and over 500 would be better) and see if you adapt to a given position. There are no hard and fast rules, just general guidelines, when it comes to these things.

Just as important as your size is your flexibility. If you have a stiff lower back, you may not be able to lean over and stretch out as much. If you are very flexible, you may get away with a longer top tube, with the stem in a lower position. Over time on the bike, too, you may become more limber, or at least become accustomed to being lower and stretched out. So, your first 'real' bike may not be anything like what you will want 5 years from now.

Someone new to road riding is highly unlikely to find their ultimate position on the first go. As they become accustomed to the riding position and get some miles in, sometimes over several seasons, people often find their desired position changing. What was "stretched out" now feels OK, or what was "just right" now feels cramped. With time, if you are working on your position along with all your other riding stuff, seat position tends to rise, handlebars tend to be farther below the saddle, saddles tend to move rearward, and handlebars tend to be farther forward from the saddle. You simply cannot say "this is the right position for someone of your body dimensions" because there are too many variables and things that change with time. Get used to your position, and then occasionally make small changes: raise/lower your saddle, move your saddle forward/backward. Ride a while with the changes (a few 100 miles, anyway) and decide if it is better or worse. If it is better, keep moving in that direction. If it is worse, try moving the other direction. If you don't try, you won't find out, but it is a long term process, often taking years, to really dial in your position. And since your strength and flexibility are changing with time, it is reasonable that your position would need to change also.