General Cycling Discussion - Question about frame sizing.

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Anders K
04-16-03, 10:57 AM
I am 176 cm that is about 5´9" I think:rolleyes: . If I want to look after a road frame with classic geometry, what frame size would fit me?
My pubic bone height (PBH) is about 84,5 cm that is about 2´9" I believe.
According to Rivendell´s catalouge, considering my length, a frame of 58,5 cm would fit me!? That sounds terrifying BIG to me:confused: . Rivendell calculate like this:
For riders between 5´8" and 5´11", PHB minus 25 cm to 26 cm (1 inch = 2.54 cm).
A friend of mine rides a beautifull Eddy Merckx. He is two inch taller than me and have a higher PHB and rides a 59 cm frame.
OK, I know Rivendell proclaimes a higher bar and that you should choose the bigger frame if in doubt between two sizes. Maybe they have a different geometry on theire bikes?
Any suggestions? I am thinking of buying a second hand road frame this summer.
Thanks:)
Anders K
04-16-03, 12:42 PM
I was thinking of a 54 cm frame or a 56 cm frame. Ofcourse I will testride it first, but there is no idea looking at a frame that is probably too big, for example 59 cm and larger. Is this right? Which size do you guys have and how tall/short are you and how does your frame suite/fit you?
I am 5'10" and had to decide recently between a 21" or 23" (58cm) frame. The 21 felt okay but the 23 really felt good, although that's probably pushing the upper limit of bike that would fit. IMO you just have to go with what feels best.
Michel Gagnon
04-16-03, 09:21 PM
There are two factors to consider: frame height and top tube length.
"Modern" sizing theories tend to go with a relatively small bike with lots of seat tube exposed. The top tube is relatively long (ex. a 56 cm frame may have a 59 or 60 cm top tube), but the idea is to allow you to put handlebars very low, sometimes as low as 15 cm below the saddle. Great for racing, but not as great for a more relaxed pace.
Rivendell tends to follow the more "traditional" theory that you should have a frame as high as possible, which means that you will have about 6-10 cm of seatpost showing and bars that will be either 5 cm lower than the saddle, or maybe level or higher if you really want a more "touring" setup. BTW, their 60 cm frame uses approximately a 59 cm top tube.
In terms of rigidity, sales persons say that a small frame is stiffer. True, until you consider that the longer seatpost negates the gains in rigidity offered by the smaller frame. So the small frame is more rigid for someone who stands on the pedals, but not for someone who sits.
Regards,
Anders K
04-17-03, 11:29 AM
Thanks for your replys, looks like it´s idea look at frames up to 58 to 59 cm. Thanks for the help.
Regards
Anders K
I stand 173cm / 5'8" and prefer to ride 55cm (C-T) frames. My 54cm Peugeot is OK, because of its long top tube, and my 57cm Peugeot is barely acceptable, because of its short-reach handlebar stem.
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