Road Cycling - What size bike? Some measurements ...

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jtown
08-19-03, 03:43 PM
Hi I'm looking for a road bike and I was just wondering if anyone out there could help me out on what size frame would be best. Here are some specs on me.

Height: 5'9"
Weight: 160lbs
Inseam: 29.75" (barefoot)
Arm length: Normal (I forget the exact measurement)

I did some of these measurements while on a bike fitting site and it said I would ride a 49 or 51. What do you guys think? I just want a general idea.

~LongRider~
08-19-03, 05:02 PM
You need to go to a bike shop, and ask a person to help you there. There are alot of factors that are important. Your inseam is one part. You build is another. Do you have long or short legs, torso, etc... Some brands have longer top tubes than others. Sit on some bikes, and see what feels the best to you. It is impossible for us to say what you will need. You could range anywhere from a 51 to a 54 the way you have it broken down. Dont guess, go get the specific fit at your LBS.
~LongRider~
08-19-03, 05:03 PM
The votes you are seeing, are probably the frame sizes these folks are riding. I almost voted for my size as well. :D

~LongRider~
08-19-03, 05:09 PM
Here is Treks alpha frame geometry chart.
BikeInMN
08-19-03, 08:27 PM
I just found this fit calculator and it's numbers are dead on what I ride when I entered my measurements. I've never been professionally fitted, but I have lots of seat-of-the-pants experience that comes from trial and error.

http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO
CarlJStoneham
08-20-03, 07:01 AM
Go to www.wrenchscience.com. They have a VERY comprehensize system that works great. Click on "WS Sizing System :: Get fit for Road and Mountain Bikes!" Good explanations/diagrams and the measurements were dead on for me...
dexmax
08-20-03, 07:23 AM
i have a 48.5 seat tube but have a Top tube of 54cm.. That's equiv. to a 53-54cm frame size.

But since I have a low standover height, i had to slope the TT a bit to achieve some clearance, hence the 49cm Seat tube. (BTW, I designed the frame).
Chi
08-20-03, 09:06 AM
I've also noticed that every manufacturer has a different way of measuring their bikes, therefore their "sizes" cannot be comparatively made against each other. I think you'd have to go to a shop and actually test ride the bike, have a specialist size you up, and recommend a proper frame size.

I'm 5'8" (people say I'm 5'10" :confused: ) and I tested out in a 56cm Bianchi, but I was recommended a 54cm LeMond a week earlier.