Figuring out lastest frame sizing trend...

[biker7]

Much has been written about frame size from crank center to top of top tube but wanted to poll the board as to top bar length or effective length with sloped top bars from seat tube center to steerer tube center relative to rider height. I am 6'1" and ride a 23 inch or 58.5 cm top bar length C-t-C. What do you guys ride? Other thing is it seems many bike manufactures for '05 are getting more into compact frame/sloped top tube geometry which makes sense to conserve frame material/increase stiffness etc. and reduce weight by running a longer seat post but there also seems to be a companion reduction in top tube effective length (not sloped tube hypotenuse if you will...but horizontal C-t-C along top tube). It seems with sloped tube bikes, the top tube effective length has gotten shorter relative to steerer tube height which is the true measure of a frame's size. Would some of the board's frame experts comment on this trend?
Thanks,
George/biker7

 

[boudreaux]

Much has been written about frame size from crank center to top of top tube but wanted to poll the board as to top bar length or effective length with sloped top bars from seat tube center to steerer tube center relative to rider height. I am 6'1" and ride a 23 inch or 58.5 cm top bar length C-t-C. What do you guys ride? Other thing is it seems many bike manufactures for '05 are getting more into compact frame/sloped top tube geometry which makes sense to conserve frame material/increase stiffness etc. and reduce weight by running a longer seat post but there also seems to be a companion reduction in top tube effective length (not sloped tube hypotenuse if you will...but horizontal C-t-C along top tube). It seems with sloped tube bikes, the top tube effective length has gotten shorter relative to steerer tube height which is the true measure of a frame's size. Would some of the board's frame experts comment on this trend?
Thanks,
George/biker7

A poll has nothing to do with it. If you currently ride a bike with a XX toptube length and it fits well,go with the same virtual TT length on a sloping toptube design. End of story.

 

[biker7]

I have to say I enjoy your posts boudreaux. They are informative...you know biking...if not also laden with brevity if not comedy which I appreciate as well. But a poll is relevant to establish a correlation or trend between rider height and top tube bar length. Just like most bike sizing is predicated on rider in-seam length relative to seat tube height which is being obsoleted by revisionist frame builders...hence my question. You need not respond of course
George

 

[RC2]

A poll wouldn't be meaningful to you or any 1 indivudual as every individual's proportions differ. One six-footer might fit best on a bike with a longer top tube than another. The key is finding what works best for you.

 

[biker7]

Guess this was a tough question. For those who have been involved with cycling for many years, frame sizing has evolved. Of course proportions matter. But within every stature which includes a population of different proportions there is a range of top tube length that work most effectively. A poll would amplify this trend. This BTW is how frame sizing correlations came into being in the first place...not only top tube length relative to seat tube height but correlating seat tube length to people's inseam measurements.
Frame sizing has continued to evolve over time and will continue to do so.
As a trend, people today ride a much smaller frame than what was common twenty years ago for example.
George

 

[boudreaux]

Guess this was a tough question. For those who have been involved with cycling for many years, frame sizing has evolved. Of course proportions matter. But within every stature which includes a population of different proportions there is a range of top tube length that work most effectively. A poll would amplify this trend. This BTW is how frame sizing correlations came into being in the first place...not only top tube length relative to seat tube height but correlating seat tube length to people's inseam measurements.
Frame sizing has continued to evolve over time and will continue to do so.
As a trend, people today ride a much smaller frame than what was common twenty years ago for example.
George

It isn't a tough question.And a bike still has to fit the person riding it , polls be dammed . FWIW, many people are riding bikes smaller than they should because of image and marketing. TT length matters, but I aslo do quite well on ones ranging from 56.3 to 57mm with adjustments to stem length. Do you buy your Jeans based on a poll of others waist and inseam lengths.

 

[biker7]

I figured you were under 6' tall

George

 

[boudreaux]

I figured you were under 6' tall

George

Wrong again.6' with a long bike inseam.

 

[biker7]

It worked...I got your size...lol
George

 

[RC2]

Me too -- 6'2".

 

[boudreaux]

It worked...I got your size...lol
George

wrong again...I lied.

 

[biker7]

...meant that figuratively

George

 

[RC2]

wrong again...I lied.

uh...uh... me too!

 

[PeterF]

Much has been written about frame size from crank center to top of top tube but wanted to poll the board as to top bar length or effective length with sloped top bars from seat tube center to steerer tube center relative to rider height. I am 6'1" and ride a 23 inch or 58.5 cm top bar length C-t-C. What do you guys ride? Other thing is it seems many bike manufactures for '05 are getting more into compact frame/sloped top tube geometry which makes sense to conserve frame material/increase stiffness etc. and reduce weight by running a longer seat post but there also seems to be a companion reduction in top tube effective length (not sloped tube hypotenuse if you will...but horizontal C-t-C along top tube). It seems with sloped tube bikes, the top tube effective length has gotten shorter relative to steerer tube height which is the true measure of a frame's size. Would some of the board's frame experts comment on this trend?
Thanks,
George/biker7

George, I'll answer. I'm 6' tall, with a 32 inseam and long arms (75" wingspan). I find that a 56.5 TT with a 130 cm stem is the best fit for me, but all of my bikes have been traditional not sloping, so I cannot comment on that style. My seatpost has about an inch of set back and I slide the saddle back about a cm past center.

 

[meehs]

Isn't it really just the relationship between the three contact points (peddles, saddle and handlebar) that's significant in terms of bike fit? It seems that whatever happens in between (compact, traditional, folding, mixte, whatever...) is somewhat irrelevant provided you don't have to run a 180mm stem (for example) to get the relationship right. So if someone wanted to run a frame with a mile of exposed seatpost, 80mm of stem spacers and a 150mm stem, just so they could shoehorn their ass onto a smaller frame size, there's really nothing stopping them. All of the B.S. about sizing "methods" between compact and traditional is really just that (B.S.)... Isn't it? You just need to find the position that works best for you and go with it.

 

[biker7]

Thank you Peter. The kind of input I was looking for. Appreciate you sharing your specs.

George

 

[RC2]

Isn't it really just the relationship between the three contact points (peddles, saddle and handlebar) that's significant in terms of bike fit? It seems that whatever happens in between (compact, traditional, folding, mixte, whatever...) is somewhat irrelevant provided you don't have to run a 180mm stem (for example) to get the relationship right. So if someone wanted to run a frame with a mile of exposed seatpost, 80mm of stem spacers and a 150mm stem, just so they could shoehorn their ass onto a smaller frame size, there's really nothing stopping them. All of the B.S. about sizing "methods" between compact and traditional is really just that (B.S.)... Isn't it? You just need to find the position that works best for you and go with it.

Yeah it's pretty simple... aside from a very long/short stem (which would screw up the handling) and getting the crank length about right. If the contact points (feet, bum, and hands) are where they should be, the geometry of everything else aint gonna matter.

 

[biker7]

True Meehs...which was also boudreaux's point as well. But, all said, many do have a "preference", relative to their height, allowing for proportion differences and most don't run a 150mm stem with spacers and lots of seat set back. The intent of the thread was to ask what people "like to run" relative to their size for perspective. Believe Peter understood the intent. That's all there is to it.
If you don't want to share your specs thats OK.
George

 

[capwater]

Height is meaningless and to a certain degree as is inseam. Tibia and fibula sizes vary within the same inseam measurement. Top tube becomes an even bigger question with arm and torso length varying widely. I have 3 bikes, all slightly different, but all real comfortable to ride. My 54" Klein has traditional geometry and a custom top tube extended by 2 cm. My compact Litespeed has been called "too small" for me by some (it's technically a 53), yet it feels great. FYI; 5'10", 190lbs, 31" inseam.

Ride a bunch of bikes especially different manufacturers. Too many variables to say "you're a 5x size". Sizing calculators can be helpful, but in the end nobody but yourself can determine fit.

 

[biker7]

good input Cappy...Thanks.

George