What bike size?

[broady]

I've got a few different bikes and they are different size frames.
I just put the seat at the right height and off I go.
How important is it to have the correct size frame?
Does it make that much of a difference?

I'm 5'10" with a 30" or 31" inside leg measurement.
What size should I look to ride?

 

[bpsmith]

It can make a huge difference. Will definitely affect your speed, but more importantly your comfort as you rude further afield. Better for the bike to be slightly too small than too big.

As far as sizing is concerned, that will depend on the type of bike and the specific model you're after, as they vary depending on geometry.

 

[smokeysmoo]

Like bpsmith says, different styles and different manufacturers will size up slightly differently.

All manufacturers websites should have sizing charts, and sites like WIGGLE have generic ones too.

FYI - if your buying new in the future and aren't sure about size then avoid buying online, visit your LBS for an informed choice.

 

[RWright]

I'm 5'10" with a 30" or 31" inside leg measurement.
What size should I look to ride?

I am nearly your same measurements, inside leg is 29 to 30 inches though. I ride a 53 and 56 Cannondale Synapse and a 56 Trek 2.3. I feel a little far out front on the 53 but I have not started tweaking the layout on it yet since I have not had it that long and since I was off the bikes for several months because of a knee. I am just doing basic short fitness rides now. I am a little faster on the smaller bike it seems but not very much. I would definitely try to ride before I bought but I think a 54 to 56 would be very close for you on those two types of frames. It depends a lot on the particular bike you choose.

 

[Gravity Aided]

Sometimes you might benefit from a smaller or larger frame all depending on what you're comfortable with.

 

[broady]

I'm looking at getting a second hand road bike. I have a old carlton cosair (large frame, maybe xl?)
A specialized sirrus (medium frame)
Giant TT bike (large)
Old Scott Boulder mountain bike (small frame)
Also a small frame single speed with drop bars

I can't afford a new bike and don't want to waste the lbs' s time when I have no intention from buying from there until finances improve

 

[broady]

The cosair is my work commuter bike

 

[Gravity Aided]

Does the Carlton Corsair fit you? It looks from here(middle of United States) to be about a 63 or 65cm. Measurement from center of bottom bracket to the top of the top tube is better than the sizes S,M,L,XL,. as it is more accurate across lines. One man's L may be another mans XL, etc.

 

[T.M.H.N.E.T]

I've got a few different bikes and they are different size frames.
I just put the seat at the right height and off I go.
How important is it to have the correct size frame?
Does it make that much of a difference?

I'm 5'10" with a 30" or 31" inside leg measurement.
What size should I look to ride?

Go and test ride bikes. Leave the height and inside leg nonsense alone..

 

[vickster]

It'll depend on what sort of bike you are actually buying and which one

 

[broady]

When I stand flat footed on the floor the crossbar on the corsair is pushing my work trousers up into my crotch, but when I wear lycra I clear it fine.
And the bike is quite comfortable to ride

 

[steveindenmark]

It all depends what you are comfortable with when riding. I am your size and all my bikes have a 54 cm frame. But my road bike is a Trek Lexa SL and is designed for women. The top tube is slightly shorter. But it suits me very well.