Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Are threaded forks tapered inside?

Notices
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.

Are threaded forks tapered inside?

Old 09-01-17, 07:50 PM
  #1  
Full Member
Thread Starter
 
Join Date: May 2012
Location: Atlanta, GA
Posts: 335

Bikes: Dave Kirk Custom, Clockwork Bikes Custom, Batavus Course Specialized HardRock x2 Trek 700 MultiTrack 1991 Trek 950 SingleTrack. Miyata Three Ten

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Are threaded forks tapered inside?

Hi,
I have a big tall dirt drop stem going into a 1 inch threaded fork. I want it to go another inch in, and looking at the inside of the tube, there is at least 2 more inches it could go, but it won't. I'm guessing the inside of the steerer column must be tapered? I was hoping to avoid cutting the stem. Thx.
byrd48 is offline  
Old 09-01-17, 08:02 PM
  #2  
Friendship is Magic
 
3alarmer's Avatar
 
Join Date: Nov 2010
Location: Sacramento, CA
Posts: 22,436

Bikes: old ones

Mentioned: 303 Post(s)
Tagged: 0 Thread(s)
Quoted: 25614 Post(s)
Liked 9,567 Times in 6,653 Posts
Steerer tube diameter

When sizing a fork to a frame, the diameter of the fork steerer or steer tube (1" or 1⅛" or 1") must not be larger than that of the frame, and the length of the steerer tube should be greater than but approximately equal to the head tube length plus the stack height of the headset. Adapter kits are available to enable use of a 1" fork in a frame designed for a 1⅛" steer tube or a 1⅛" fork in a 1" frame.

Manufacturers of high-end bikes, both road and mountain, have started to use tapered steerer tubes. While there are purported advantages, there are not any standards yet developed, with each manufacturer following its own conventions. This makes replacement parts difficult to come by, only available from the original manufacturer.https://en.wikipedia.org/wiki/Bicycl..._tube_diameter
...this refers, if I'm not mistaken, to the outside diameter of the steerer, but you do run into a number of issues trying to drop a stem all the way into many threaded steerer forks, either because they are butted at the bottom, or because there is some obstruction in the lower section. If it looks like straight wall tubing, you can ream it out with the proper tool, but most people choose instead to reduce the lower stem diameter by sanding or grinding.

There's no good universal answer. If it won't go down, don't force it.
3alarmer is online now  
Old 09-01-17, 08:12 PM
  #3  
Full Member
Thread Starter
 
Join Date: May 2012
Location: Atlanta, GA
Posts: 335

Bikes: Dave Kirk Custom, Clockwork Bikes Custom, Batavus Course Specialized HardRock x2 Trek 700 MultiTrack 1991 Trek 950 SingleTrack. Miyata Three Ten

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by 3alarmer
Steerer tube diameter



...this refers, if I'm not mistaken, to the outside diameter of the steerer, but you do run into a number of issues trying to drop a stem all the way into many threaded steerer forks, either because they are butted at the bottom, or because there is some obstruction in the lower section. If it looks like straight wall tubing, you can ream it out with the proper tool, but most people choose instead to reduce the lower stem diameter by sanding or grinding.

There's no good universal answer. If it won't go down, don't force it.
Thanks, butted is the better word, not tapered.
byrd48 is offline  
Old 09-01-17, 08:47 PM
  #4  
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 24,736

Bikes: Several, mostly not name brands.

Mentioned: 153 Post(s)
Tagged: 0 Thread(s)
Quoted: 3484 Post(s)
Liked 3,152 Times in 1,807 Posts
Steer tubes are often butted, meaning that the lower end of the tube has a thicker wall than the upper end of the tube. This can prevent your quill stem from fully inserting into the fork.
JohnDThompson is offline  
Old 09-02-17, 05:29 AM
  #5  
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Posts: 8,319

Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta

Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 1438 Post(s)
Liked 1,090 Times in 722 Posts
Here is an article on butted steerers and the danger of trying to clamp a quill stem too far down in them. https://www.sheldonbrown.com/handsup.html#danger
dsbrantjr is offline  
Old 09-02-17, 08:23 PM
  #6  
Senior Member
 
maddog34's Avatar
 
Join Date: Jul 2015
Location: NW Oregon
Posts: 2,972

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: 1295 Post(s)
Liked 736 Times in 531 Posts
the steerer tube on the fork may have a seam where the tubing was joined during manufacture... it may not have been reamed out all the way through...

https://www.metalsupermarkets.com/di...seamless-tube/

note how the ERW tubing is dressed after welding only on the OUTSIDE diameter... a fork steerer made of this tubing would then be reamed to allow a good fit to the quill type stems... that process may not have been done all the way down through the tube... time is money during manufacturing...

Last edited by maddog34; 09-02-17 at 08:29 PM.
maddog34 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
TallRider
Bicycle Mechanics
7
07-22-18 11:27 PM
Shinkers
Classic & Vintage
15
03-10-17 05:58 AM
Nessism
Bicycle Mechanics
19
09-03-13 07:16 PM
eyeomegasquared
Bicycle Mechanics
13
09-08-12 10:12 AM
SactoDoug
Bicycle Mechanics
6
11-17-10 05:08 PM

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 - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.