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

Miling the RST Gila steerer tube (1'' threaded) to install 26.4 crown race

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.

Miling the RST Gila steerer tube (1'' threaded) to install 26.4 crown race

Old 01-17-19, 07:37 AM
  #1  
Watsoon
Junior Member
Thread Starter
 
Join Date: Jul 2018
Location: Ukraine, Kharkiv
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Miling the RST Gila steerer tube (1'' threaded) to install 26.4 crown race

Hello! I have suspension RST Gila fork with 1 inch threaded steerer. The crown race seat size is 27.1 mm (for crown races of 27 mm). Steel steerer is pressed into aluminium crown. The crown race is pressed just onto the steerer tube. But I has the headset with crown race of 26.4 mm. Can I mill down the steerer from 27.1 mm to 26.5 mm to install the crown race? I am afraid that the wall thickness will become too small and the steerer can broke. Is it safe to do that?
Watsoon is offline  
Old 01-17-19, 07:49 AM
  #2  
Dan Burkhart 
Senior member
 
Dan Burkhart's Avatar
 
Join Date: Oct 2004
Location: Oakville Ontario
Posts: 7,353
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 580 Post(s)
Liked 52 Times in 40 Posts
Originally Posted by Watsoon View Post
Hello! I have suspension RST Gila fork with 1 inch threaded steerer. The crown race seat size is 27.1 mm (for crown races of 27 mm). Steel steerer is pressed into aluminium crown. The crown race is pressed just onto the steerer tube. But I has the headset with crown race of 26.4 mm. Can I mill down the steerer from 27.1 mm to 26.5 mm to install the crown race? I am afraid that the wall thickness will become too small and the steerer can broke. Is it safe to do that?
Find a shop with a proper crown race milling tool. If you're local to me, I can do the job, but your location is not indicated. Let us know where you are, and maybe someone can make suggestions.
It involves milling the crown race seat, not the steer tube, so there is no danger.
Dan Burkhart is offline  
Old 01-17-19, 07:56 AM
  #3  
HillRider
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 31,698

Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!

Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 1229 Post(s)
Likes: 0
Liked 68 Times in 60 Posts
This was commonly done on older JIS (27.0) forks to allow fitting an ISO (26.4) crown race. It's a safe procedure if done properly.

My 1985 Bridgestone 400 came with a JIS headset and my LBS milled the fork crown to ISO size when I replaced the OEM headset. That bike is still in use.
HillRider is offline  
Old 01-17-19, 07:57 AM
  #4  
TimothyH
- Soli Deo Gloria -
 
Join Date: Aug 2015
Location: Northwest Georgia
Posts: 14,784

Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix

Mentioned: 233 Post(s)
Tagged: 0 Thread(s)
Quoted: 6822 Post(s)
Liked 652 Times in 410 Posts
I had a 27 mm Japanese fork milled to 26.4 mm ISO.

It wasn't easy to find someone in Atlanta who understood what I wanted to do, let alone had the tool and was willing. Eventually I found an older mechanic at a bike shop who used to build frames. He was like, "Yeah, bring it" and charged me $25. The tool was pretty dusty, hadn't been used in a while.

As Dan said, the race seat is milled, not the steerer. Don't give it a second thought.


-Tim-
TimothyH is offline  
Old 01-17-19, 08:00 AM
  #5  
Watsoon
Junior Member
Thread Starter
 
Join Date: Jul 2018
Location: Ukraine, Kharkiv
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Dan Burkhart View Post
Find a shop with a proper crown race milling tool. If you're local to me, I can do the job, but your location is not indicated. Let us know where you are, and maybe someone can make suggestions.
It involves milling the crown race seat, not the steer tube, so there is no danger.
I am very far from you (city of Kharkiv, Ukraine, Europe). But the crown race seat is not a part of the crown. It is just the part of steerer tube. Steerer is butted and has larger diameter at the bottom. I can't insert images (less than 10 posts), but you can just google for "suspension forks" and see that.

Last edited by Watsoon; 01-17-19 at 08:16 AM. Reason: i need to do that
Watsoon is offline  
Old 01-17-19, 09:15 AM
  #6  
Crankycrank
Senior Member
 
Join Date: Jan 2009
Location: San Diego, CA
Posts: 1,379
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 202 Post(s)
Likes: 0
Liked 18 Times in 11 Posts
First check if the manufacturer of your headset offers a JIS crown race. Some do and if not some are interchangeable with other brands but you may need to do some research to find a compatible race.
Crankycrank is offline  
Old 01-17-19, 09:20 AM
  #7  
Reynolds 531
Senior Member
 
Join Date: Oct 2014
Location: Reno nevada
Posts: 342

Bikes: 4 Old school BMX, 6 Klunkers, 5 29er race bikes, 4 restored Sting Rays, Now 3 vintage steel bike being built up

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 142 Post(s)
Liked 29 Times in 22 Posts
Originally Posted by Crankycrank View Post
First check if the manufacturer of your headset offers a JIS crown race. Some do and if not some are interchangeable with other brands but you may need to do some research to find a compatible race.
Smart^

The old solutions that we all love, and instinctively jump to, have often been superced by the solution of the young creators.
Reynolds 531 is offline  
Old 01-17-19, 09:26 AM
  #8  
mrv 
BIKE RIDE
 
Join Date: Jun 2014
Location: Michigan
Posts: 917

Bikes: 198? Specialized RockHopper / 2013 KONA JtS / 1985 Asian Modification / and that's not ALL!

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 173 Post(s)
Liked 6 Times in 6 Posts
i have a mid-80s TREK. I think I could not get the right JIS stack height, so I milled to ISO. Or maybe I had already bought the headset and found out it was the wrong size after trying to seat it. Anyway, my LBS let me rent his mill. It was still in the original shipping wax from PARK TOOL. He's been in business more than 10 years. I'm the first to ask about using the tool....
mrv is offline  
Old 01-18-19, 08:07 PM
  #9  
calstar 
Senior Member
 
calstar's Avatar
 
Join Date: Mar 2012
Location: santa barbara CA
Posts: 1,003
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked 3 Times in 3 Posts
Know anyone with a lathe? This is a basic turning procedure easily done on a lathe.
He also is measuring/cutting axle to crown race dimension, you've might have guessed Mr. Tanabe
is a master builder, check out his other vids.
regards, Brian
__________________
"The older I get the better I was" Brian

Last edited by calstar; 01-18-19 at 08:36 PM.
calstar is offline  
Old 01-18-19, 08:26 PM
  #10  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 12,145

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1921 Post(s)
Liked 121 Times in 93 Posts
Originally Posted by calstar View Post
Know anyone with a lathe? This is a basic turning procedure easily done on a lathe.

regards, Brian
With a large enough spindle through hole/ID. Here in the states that means a lathe with a 10' to 12" swing usually. Of course care must be taken when one has shirt grabbing tangs spinning at high RPMs right in front of them Andy
__________________
AndrewRStewart
Andrew R Stewart is offline  
Old 01-18-19, 08:45 PM
  #11  
calstar 
Senior Member
 
calstar's Avatar
 
Join Date: Mar 2012
Location: santa barbara CA
Posts: 1,003
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Liked 3 Times in 3 Posts
Originally Posted by Andrew R Stewart View Post
,,,,,,,. Of course care must be taken when one has shirt grabbing tangs spinning at high RPMs right in front of them Andy
+100, but if one isn't careful 100% of the time they have no business operating a lathe or any other machining tools.

Brian
__________________
"The older I get the better I was" Brian
calstar is offline  
Old 01-19-19, 02:11 PM
  #12  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,396

Bikes: 8

Mentioned: 188 Post(s)
Tagged: 0 Thread(s)
Quoted: 6937 Post(s)
Liked 253 Times in 208 Posts
Originally Posted by Watsoon View Post
I am very far from you (city of Kharkiv, Ukraine, Europe). But the crown race seat is not a part of the crown. It is just the part of steerer tube. Steerer is butted and has larger diameter at the bottom. I can't insert images (less than 10 posts), but you can just google for "suspension forks" and see that.
OK , try the reverse ..you do the search, find the model you have then write back with those results ... being your inquiry..

You have any friends working in a machine shop?
they may help you putting the fork in the Lathe & cutting until your crown race fits..
on the crown race seat at the base of your steerer tube..
fietsbob is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
markwesti
Bicycle Mechanics
11
10-13-15 01:13 PM
adlai
Bicycle Mechanics
22
07-17-14 05:58 PM
degan
Classic & Vintage
9
12-17-12 11:44 AM
James1:17
Bicycle Mechanics
4
07-03-12 06:20 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


Thread Tools
Search this Thread

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

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.