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

can an 8 inch disc pull the front wheel out of the fork?

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.

can an 8 inch disc pull the front wheel out of the fork?

Old 06-11-05, 10:03 PM
  #1  
byondspun
Newbie
Thread Starter
 
Join Date: Jun 2005
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
can an 8 inch disc pull the front wheel out of the fork?

i am considering putting an 8 inch disc on the front of my bike, but have been told that the torque from the stronger disc( i have a 6 inch avid on there now) can pull the front wheel out of the fork under hard braking. i run allen key skewers now. is this the guy in the store trying to sell me through axle hubs or a real possibility? thanks
byondspun is offline  
Old 06-11-05, 10:08 PM
  #2  
grolby
Senior Member
 
grolby's Avatar
 
Join Date: Jan 2005
Location: BOSTON BABY
Posts: 9,632
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 235 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Yes, it most certainly is a possibility! http://www.ne.jp/asahi/julesandjames...quick_release/

I don't know that it's particularly likely, but torque from disc brakes causing front wheels to come out of the fork dropouts is a documented problem.
grolby is offline  
Old 06-12-05, 12:53 AM
  #3  
spleck
Senior Member
 
Join Date: May 2004
Location: Warner Robins, GA
Posts: 86

Bikes: 2005 Specialized HardRock Sport, 1996 Schwinn Sierra

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Do any manufacturers still use safety clips? I've got a 10 year old Schwinn that has screws on the inside of both fork arms. On the front wheel are two metal arms that clip onto those screws. Once on, the wheel won't come off until you push these arms/tabs inward to unclip them.
spleck is offline  
Old 06-12-05, 01:07 AM
  #4  
catatonic
Chairman of the Bored
 
catatonic's Avatar
 
Join Date: May 2004
Location: St. Petersburg, FL
Posts: 5,825

Bikes: 2004 Raleigh Talus, 2001 Motobecane Vent Noir (Custom build for heavy riders)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
No, but most forks now have "lawyer lips" of one form or another which may help keep the wheel in place.

I know my fork on my mountain bike has large circular lips on it, which ensure you cannot get the wheel off even with the skewer wide open without a significant amount of turns on the nut. It has a 6" rotor as well.

I'd almost think the torque is a function of where the brake is located, as most disc brakes are well over 45 degrees from the top position most canti/vbrake/caliper brakes would be located.
catatonic is offline  
Old 06-12-05, 04:02 AM
  #5  
CdCf
Videre non videri
 
Join Date: Sep 2004
Location: Gothenburg, Sweden
Posts: 3,208

Bikes: 1 road bike (simple, light), 1 TT bike (could be more aero, could be lighter), 1 all-weather commuter and winter bike, 1 Monark 828E ergometer indoor bike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
After reading that article about disc brakes pulling the wheel out of the fork, I set up an Excel sheet to calculate the forces involved.

The larger the disc, the lower the ejecting force at the wheel axis.
If the article is correct about the maximum ejecting forces quick releases have to be able to withstand, then a 203 mm (8") disc is actually enough to take the ejecting force down to, or below, that limit, provided you don't decelerate harder than about 0.5 G.
CdCf is offline  
Old 06-12-05, 07:19 AM
  #6  
phantomcow2
la vache fantôme
 
phantomcow2's Avatar
 
Join Date: Aug 2004
Location: NH
Posts: 6,266
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
If im not mistaken, some manufacturers dont even warranty their fork if it is being used with 8" rotors. So make sure that your fork can take that. ANd yes, it is possible for the wheel to be pulled out
__________________
C://dos
C://dos.run
run.dos.run
phantomcow2 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
foranswer
For Sale
0
09-26-17 11:14 AM
mwl001
Hybrid Bicycles
0
06-06-14 02:48 PM
PolishPostal
Road Cycling
0
08-31-06 08:09 AM
stabbypete
Singlespeed & Fixed Gear
1
09-07-05 06:15 PM
stella
Advocacy & Safety
0
04-25-02 05:32 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.