Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.


Old 07-30-17, 12:59 AM
Thread Starter
Join Date: Jul 2017
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts

What is standard frame measurement of bike?
mostafizrahman is offline  
Old 07-30-17, 01:00 AM
Thread Starter
Join Date: Jul 2017
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
What is standard frame measurement of bike?
mostafizrahman is offline  
Old 07-30-17, 01:25 AM
Senior Member
Join Date: Jan 2015
Posts: 443
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Likes: 0
Liked 23 Times in 19 Posts
trailflow1 is offline  
Old 07-30-17, 06:55 AM
Senior Member
Join Date: Apr 2006
Posts: 3,652
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 381 Post(s)
Likes: 0
Liked 107 Times in 80 Posts
Generally it is from the center of the bottom bracket to the middle of the top tube at the seat tube or top of the seat tube (Schwinns were measured that way). With new sloping top tube bikes that has that has turned to the to the place on the seat tube where a straight top tube would have gone. Roger
rhenning is offline  
Old 07-30-17, 07:05 AM
Licensed Bike Geek
Davet's Avatar
Join Date: Oct 2002
Location: Los Barriles, Baja Sur, Mexico
Posts: 1,360

Bikes: Look 585, Kirk Terraplane, Serotta Ottrott, Spectrum Super Custom, Hampsten Carbon Leger Tournesol

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 92 Post(s)
Liked 69 Times in 48 Posts
If you're referring to the way a manufacturer states the size of their frame, there is no 'standard' of frame measurement.
Davet is offline  
Old 07-31-17, 02:22 AM
Senior Member
maddog34's Avatar
Join Date: Jul 2015
Location: NW Oregon
Posts: 3,020

Bikes: !982 Trek 930R Custom, Diamondback ascent with SERIOUS updates, Fuji Team Pro CF and a '09 Comencal Meta 5.5

Mentioned: 15 Post(s)
Tagged: 1 Thread(s)
Quoted: 1317 Post(s)
Liked 763 Times in 553 Posts
best way to measure frame size these days is... from center of head tube near it's top, to a center point on the seat tube or seat post directly rearward from the head tube in a horizontal, level line.
maddog34 is offline  
Old 07-31-17, 07:59 AM
Full Member
Join Date: Dec 2014
Location: Retired to Penang Malaysia originally from UK
Posts: 346

Bikes: My 1978 Raleigh from new, 1995 Trek, & constant changing & rebuilding of other bike projects.

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
You need to look this up on the web there are loads of very good information & videos, also you have not mentioned what type of frame you are referring to, as there are several variations depending on frame design & type.
Bike tinker man is offline  
Old 07-31-17, 08:15 AM
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,598

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,360 Times in 866 Posts
center of BB along Seat tube is commonly called Frame Size

Top tube can be divided up by a plumb line thru the BB, set back behind, reach, ahead of that line.
that gives some idea of seat tube angle ... top tube length is just a total , center to center..

then chain stay length.. this is not saying anything about the fork

that's a separate set of answers.

fietsbob is offline  
Old 07-31-17, 08:31 AM
Senior Member
Join Date: May 2011
Location: Upstate NY
Posts: 3,783

Bikes: Bianchi San Mateo and a few others

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 634 Post(s)
Likes: 0
Liked 13 Times in 9 Posts
There is no single, uniform standard.

Traditionally, on road bikes with horizontal top tubes, frame size was measured along the seat tube. Everyone pretty much agreed that the low point was the center of the bottom bracket shell, but the top end of the measurement could be the center of the top tube, the top of the top tube, or the top of the seat tube. And because of geometry differences between makes and models, two bikes that are listed as the same size might fit differently. Their top tubes could be different lengths, for example.

On more modern road bikes with sloping or curved top tubes, numeric sizes generally aren't measurements, but equivalents to bikes with horizontal top tubes as rhenning mentioned above. My 2006 Bianchi has a sloping top tube, so we can use it as an example. It's a 53 cm frame, but its seat tube is only 50 cm long. If I was to draw an imaginary horizontal line from the junction of the top tube and the head tube back to the seatpost, that line would probably be about 53 cm from the center of the bottom bracket.

Some manufacturers don't even bother with 'virtual' or 'effective' measurements and just label them small/medium/large, etc.

...and if we're talking about bikes other than road bikes, different sizing conventions may apply. For example, road bike frame sizes haven't been listed in inches for a few decades now, but it's still the norm for mountain bikes.
SkyDog75 is offline  
Related Topics
Thread Starter
Last Post
Tandem Tom
10-29-18 11:35 AM
Bicycle Mechanics
02-13-18 02:29 PM
Bicycle Mechanics
08-04-11 06:27 PM
Road Cycling
07-07-10 05:09 PM
Mountain Biking
12-23-09 10:21 AM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.