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I am 5 ft 11 1/2 " with an inseem of 32-33 inches.

I am loking at a 58 cm bike on ebay. Do you think this will be a good fit?

Thanks
 

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Sounds about right...

mab05 said:
I am 5 ft 11 1/2 " with an inseem of 32-33 inches.

I am loking at a 58 cm bike on ebay. Do you think this will be a good fit?

Thanks
Hard to say exactly from just those two measurements but it sounds like it is in the right ballpark. You should be able to make it work.

Mike
 

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eminence grease
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I'm 5'11" and I ride 56, 57 and 58 bikes. In some brands I could even ride a 59.

While you may be in the correct neighborhood, the devil is in the details. There are 58s that I would never consider.

My advice - find out all the measurements on the bike - top tube, seat tube, head tube and then go and find some bikes to sit on. It's the only correct way to know if this particular 58 will work for you or not.
 

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Good advice...

Good advice from terry b. I assumed you were talking about the top tube. It is hard to say what a 58 c bike is without knowing how they measured it. Top tube and seat tube angle would be more valuable information.

Mike
 

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WAAAY to fuzzy!

mab05 said:
I am 5 ft 11 1/2 " with an inseem of 32-33 inches. I am loking at a 58 cm bike on ebay. Do you think this will be a good fit?
Neither your inseam measurement nor the bike size provides enough information to offer any suggestions. Bike frames can be measured in several different ways, and the difference can be several cm. And you are telling us that you don't know your inseam within 2 cm. Here's what you need to do to get the measurements right:

Measure your inseam: stand against a wall with your feet 6 inches/15 cm apart. 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.
 
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