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.

Crank arm bolt stuck!!

Old 06-01-17, 10:09 PM
  #1  
Wafa
Junior Member
Thread Starter
 
Join Date: May 2017
Posts: 6
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Crank arm bolt stuck!!!

Hi guys, having a bit of problem here.

I want to replace my crankset coz it's already worn out, but I when I trying to undo the crank arm bolt, it was stuck and I have no idea what to do.

I have a FSA Megaexo crankset which I need to use a 8mm hex key to take off the crank arm.

Please help me everyone who know what to do!!!!

Thanks
Wafa is offline  
Old 06-03-17, 04:59 PM
  #2  
blakcloud 
Senior Member
 
blakcloud's Avatar
 
Join Date: Aug 2007
Location: Toronto, Ontario
Posts: 1,904

Bikes: Rivendell Sam Hillborne, Brompton S/M3L (modified), custom Winter Cycles

Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 311 Post(s)
Liked 11 Times in 6 Posts
You should ask in the mechanics forum for a better and more detailed response.

Information you might like to add. When you say the crankset is worn out, what exactly is worn? Is it the chain rings or bottom bracket.

Have a look at this video and website. How to Remove and Install a Crank | Park Tool

Did you remove the non drive side crank arm? If so hit the axle with the rubber mallet to drive out the drive side sometimes it is a little stuck.
blakcloud is offline  
Old 06-03-17, 08:13 PM
  #3  
UniChris
Senior Member
 
UniChris's Avatar
 
Join Date: May 2017
Location: NYC
Posts: 757

Bikes: 36" Unicycle

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 328 Post(s)
Liked 56 Times in 48 Posts
Originally Posted by Wafa View Post
I have a FSA Megaexo crankset which I need to use a 8mm hex key to take off the crank arm.
You may be unable able to do this with a hex key if it is as tight as crank fixing bolts sometimes are (though many loose preload in use)

For about $2 at a big-box home store or well supplied hardware store you can buy an 8mm hex bit to fit on a 3/8" drive socket wrench. A full size handle gives substantially more leverage than an "extra long" hex key, and fits in the hand better too.

Or you can get the park special purpose CCW-5 wrench, but if you already have a socket handle the bit for that is cheaper and more readily available.

A larger wrench may however require some judgement in reinstalling - unlike with a hex key the possibility for getting it too tight now exists.

Last edited by UniChris; 06-03-17 at 08:29 PM.
UniChris is offline  
Old 06-04-17, 05:51 AM
  #4  
Wafa
Junior Member
Thread Starter
 
Join Date: May 2017
Posts: 6
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Crank arm bolt stuck!!

Hi guys, having a bit of problem here.

I want to replace my crankset coz it's already worn out and wants to replace it with a new crankset, but I when I trying to undo the crank arm bolt, it was stuck and I have no idea what to do.

I have an FSA Megaexo crankset which I need to use an 8mm hex key to take off the crank arm.

Please help me everyone who know what to do!!!!

Thanks
Wafa is offline  
Old 06-04-17, 07:06 AM
  #5  
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 20,417

Bikes: Several, mostly not name brands.

Mentioned: 109 Post(s)
Tagged: 0 Thread(s)
Quoted: 1689 Post(s)
Liked 60 Times in 41 Posts
An 8mm hex socket in a breaker bar is what I'd use. Slide a cheater pipe over the breaker bar if you need more leverage.
JohnDThompson is offline  
Old 06-04-17, 10:05 AM
  #6  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,928

Bikes: 8

Mentioned: 188 Post(s)
Tagged: 0 Thread(s)
Quoted: 6833 Post(s)
Likes: 0
Liked 212 Times in 177 Posts
Yup, Leverage.. @ the LBS we have a long 8mm with a handle.

... but an 8mm bit, 1/2" drive, will get you a longer beefier wrench handle to get the extra force ..

Might need a friend to hold the opposite crank arm.




...
fietsbob is offline  
Old 06-04-17, 10:49 AM
  #7  
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 20,417

Bikes: Several, mostly not name brands.

Mentioned: 109 Post(s)
Tagged: 0 Thread(s)
Quoted: 1689 Post(s)
Liked 60 Times in 41 Posts
Originally Posted by fietsbob View Post
Might need a friend to hold the opposite crank arm.
For particularly stubborn cranks, remove the opposite pedal and slip a cheater pipe over that crank arm as well, so you have extra leverage on both the breaker bar and the opposite arm.
JohnDThompson is offline  
Old 06-04-17, 11:04 AM
  #8  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,928

Bikes: 8

Mentioned: 188 Post(s)
Tagged: 0 Thread(s)
Quoted: 6833 Post(s)
Likes: 0
Liked 212 Times in 177 Posts
You double posted, dont like the other answers?
fietsbob is offline  
Old 06-04-17, 01:01 PM
  #9  
WizardOfBoz
Generally bewildered
 
WizardOfBoz's Avatar
 
Join Date: Aug 2015
Location: Eastern PA, USA
Posts: 1,864

Bikes: 2014 Trek Domane 6.9, 1999 LeMond Zurich, 1978 Schwinn Superior

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 656 Post(s)
Liked 27 Times in 23 Posts
The "bigger wrench" approach appears to work, and you have some guys with long, deep experience giving you valuable advice.

If it still seems "stuck", I can tell you how mechanics and machinists break loose bolts. One is chemical, the other is heat.

Chemical. Lay the bike on its side and spray some Kroil or Liquid Wrench in the cup where the bolt is. You should form a little pool of the stuff. Let it soak in overnight. Then try the mechanic's secret approaches above. Heat. If no joy, you could try heating the thing with a bernzomatic torch. Heat the bolt up (not read hot, but get it plenty warm). Again, with the bike on its side so that the heat is focused on the bolt. Best to heat it for a while, from a distance, so that the heat can get into the threaded section of the bolt. Let it cool for an hour. Then try to use mechanical advantage.
WizardOfBoz is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
madhandles
Bicycle Mechanics
3
06-18-09 10:42 PM
cpsqlrwn
Road Cycling
0
05-03-08 03:26 PM
Fuse4
BMX
4
11-16-07 05:01 AM
onelesscar
Bicycle Mechanics
1
10-20-05 05:56 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


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.