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 06-21-08, 11:39 AM   #1
sn00ke
Member
Thread Starter
 
Join Date: Apr 2008
Bikes:
Posts: 26
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
How to remove a one-piece crank?

Yeah don't say it, I know its a sign of a garbage bike, but its what I have to work with. I'm planning on replacing it with Altus cranks from an old bike I stripped, only I'm not sure how to go about removing them.

This isn't the same model as mine, but they look essentially the same:


I figure that taking a wrench to the giant hex on one side has something to do with it, but overall I'm mystified.

Also does anyone think that I'll run into compatibility issues with installing a new crank onto what must be a cheap bracket down there?

Last edited by sn00ke; 06-21-08 at 11:50 AM.
sn00ke is offline   Reply With Quote
Old 06-21-08, 12:02 PM   #2
kramnnim
Senior Member
 
Join Date: May 2007
Bikes:
Posts: 705
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yeah, just loosen that hex nut.

The BB shell on it is not threaded...you'll need some kind of adapter or special BB to use a 3 piece crankset with it...
kramnnim is offline   Reply With Quote
Old 06-21-08, 12:13 PM   #3
sn00ke
Member
Thread Starter
 
Join Date: Apr 2008
Bikes:
Posts: 26
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
My actual crank is 3-geared, will I still have a problem?
sn00ke is offline   Reply With Quote
Old 06-21-08, 12:34 PM   #4
JiveTurkey
Low car diet
 
JiveTurkey's Avatar
 
Join Date: Aug 2007
Location: Corvallis, OR, USA
Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.
Posts: 2,407
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
This should answer your questions: http://sheldonbrown.com/opc.html
JiveTurkey is offline   Reply With Quote
Old 06-21-08, 05:00 PM   #5
griftereck
Senior Member
 
Join Date: Jun 2008
Location: angus scotland
Bikes: Grifter BSA 20
Posts: 600
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Ive got a DMR adaptor rings
they sit in the frame and have the long bolts to hold them in
theres standard bsa threads in side them so you can screw in a normal 3 peice bottom bracket

also have a Raleigh ladies mtb that has a cheap bb in a american style bb.
think its a standard raleigh part.
griftereck is offline   Reply With Quote
Old 06-21-08, 06:27 PM   #6
c_m_shooter
Senior Member
 
c_m_shooter's Avatar
 
Join Date: Sep 2006
Location: Paradise, TX
Bikes: Surly Cross Check, Redline Monocog 29er, Generic Track bike, Surly Pugsley, Salsa Fargo, Schwinn Klunker
Posts: 1,542
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It's probably not worth the expense of converting once you figure the cost of the adaptor plus the new crankset, bottom bracket, and pedals. Unless you really need to use clipless pedals.....
c_m_shooter is offline   Reply With Quote
Old 06-21-08, 11:26 PM   #7
kevbo
Senior Member
 
Join Date: Oct 2007
Bikes:
Posts: 321
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
All the threads on the left side are left-handed (Bass Ackwards)

After you remove the left pedal, left locknut, and cone, you will need to remove the ball races as soon as possible. The left crank arm will come out through the cups, but not with the ball races in place.

If you can find a bike store that caters to the BMX riders, there are some better Astabula style cranks, pedals, and bearing sets available.

Yes, I fix bikes for the kids in the neighborhood....why do you ask?

Edited to add: Beware of over tightening the cones. The cups are all soft steel, but case hardened. If you run them tight, you will crack the case hardening and ruin the cups. If it has a coaster brake, be sure to locktite and tighten the buhjesus out of the fixed cone. (holds the chainring on the crank) The drive pin has some slop in the hole in the chain ring, and thus the chainring can turn just a smidgen on the crank. I have seen that cause the fixed cup to loosen, which tightens the bearing adjustment...took me two bearing sets to figure that one out...fortunatly they are cheap.

Last edited by kevbo; 06-21-08 at 11:34 PM.
kevbo is offline   Reply With Quote
Old 06-22-08, 12:37 AM   #8
sn00ke
Member
Thread Starter
 
Join Date: Apr 2008
Bikes:
Posts: 26
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Hmm so pretty much all I have to do is take out the entire assembly, slap one of these in

And I can install a standard bracket/cranks? Sounds pretty simple, thanks alot!
(note: I already have the replacement parts, they're old but haven't been used much)
sn00ke 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 03:26 AM.