Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-29-15, 11:18 AM   #1
cncwhiz
Senior Member
Thread Starter
 
Join Date: Jun 2013
Location: Carson Valley, Nevada
Bikes: Treak 6000 mountain bike, Specialized hard rock moutain bike, Amp research b3 mountain bike, Old road bike unknown brand and year.
Posts: 90
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Threaded fork tube length

I there a ratio or a chart that I can download that will tell me how long the threaded fork tube needs to be for the frame. I bought a bigger frame because my other frame was a little small. I did not get the matching forks with the frame. I know the diameter is not in question. When the cups, bearings are installed is there a length that I need to have sticking out for the remaining hardware? Will thread less forks convert for my older frame.
cncwhiz is offline   Reply With Quote
Old 09-29-15, 11:28 AM   #2
habilis
Senior Member
 
Join Date: Apr 2015
Location: Morris County, NJ
Bikes: 90's Bianchi Premio, Raleigh-framed fixed gear, Trek 3500, Centurion hybrid, Dunelt 3-spd, Trek 800
Posts: 1,103
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by cncwhiz View Post
I there a ratio or a chart that I can download that will tell me how long the threaded fork tube needs to be for the frame. I bought a bigger frame because my other frame was a little small. I did not get the matching forks with the frame. I know the diameter is not in question. When the cups, bearings are installed is there a length that I need to have sticking out for the remaining hardware? Will thread less forks convert for my older frame.
Fork Steering Column Length and Sizing - Park Tool
habilis is offline   Reply With Quote
Old 09-29-15, 11:28 AM   #3
AnkleWork
Senior Member
 
Join Date: Jan 2013
Location: High Plains
Bikes: old clunker
Posts: 2,074
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 49 Post(s)
It's impossible to measure, and you would not want to anyway.
AnkleWork is offline   Reply With Quote
Old 09-29-15, 12:16 PM   #4
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 20,482
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 666 Post(s)
Many Possibilities .. If You have access to the proper Tools or Bought services of those who have invested in the tools,

I have had my touring bike Fork, made extra Tall and threaded it down Further ,
and used the extra height via spacers
and some special Thin Nuts I Had Hoarded (from past shop assemblies that didn't need them)

to mount a Bell on a Spacer tube and still have plenty of Bar Height ..

Used a Long Quill stem inserted well into the fork to support the cut thread length.


If you want to seek out a threadless fork You are welcome to Try,

Just The Market for 1" threadless forks is past , so the search will be a bit more challenging ..

Last edited by fietsbob; 09-29-15 at 12:20 PM.
fietsbob is online now   Reply With Quote
Old 09-29-15, 02:53 PM   #5
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 30,009
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 390 Post(s)
It's very straightforward.

The steerer length measured from the crown seat to the top must be longer than the end to end head tube length by the stack height of the headset.

You'll find headset stack height data in the headset's spec sheet, or can search using phrases like headset stack height for (model).

Typically stack heights vary between 33 and 45mm (with exceptions) so if you buy a fork 50mm taller than the frame you'll be fine, and can use spacers or trim it to fit.

WARNING -- do not buy a fork more than 60mm taller than the head tube. Quality forks only have about 50mm of thread, and if trimmed too much will run out of thread.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline   Reply With Quote
Old 09-29-15, 03:09 PM   #6
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Bikes: Several, mostly not name brands.
Posts: 16,537
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 129 Post(s)
For a threaded headset, the steer tube needs to be at least as long as the head tube plus the stack height of the headset. Threaded headset stacks vary in height between about 30mm and 44mm, depending on model. So, don't trim your steer tube until you know what headset you will be using, and it's better to cut it longer than you'll think you need, as you can always use spacers to take up the space. Here are some examples:



Source: Barnett's Manual
JohnDThompson is offline   Reply With Quote
Old 09-29-15, 04:14 PM   #7
cncwhiz
Senior Member
Thread Starter
 
Join Date: Jun 2013
Location: Carson Valley, Nevada
Bikes: Treak 6000 mountain bike, Specialized hard rock moutain bike, Amp research b3 mountain bike, Old road bike unknown brand and year.
Posts: 90
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
[QUOTE=JohnDThompson;18204404]For a threaded headset, the steer tube needs to be at least as long as the head tube plus the stack height of the headset. Threaded headset stacks vary in height between about 30mm and 44mm, depending on model. So, don't trim your steer tube until you know what headset you will be using, and it's better to cut it longer than you'll think you need, as you can always use spacers to take up the space. Here are some examples:



Source: Barnett's Manual[/QUOTE


Do you have any for 1 1/8?
cncwhiz is offline   Reply With Quote
Old 09-29-15, 07:31 PM   #8
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Bikes: Several, mostly not name brands.
Posts: 16,537
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 129 Post(s)
Quote:
Originally Posted by cncwhiz View Post
Do you have any for 1 1/8?
Not me, but a google search came up with this (in German):

JohnDThompson is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 01:45 PM.