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

Crank fell off while riding!

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 fell off while riding!

Old 06-26-06, 11:48 AM
  #1  
diff_lock2
Senior_Member2
Thread Starter
 
diff_lock2's Avatar
 
Join Date: Apr 2006
Location: Finlando NOT: Orlando, Fl
Posts: 1,694

Bikes: Beater + Nishiki Bigfoot X-29

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Crank fell off while riding!

So after some root/rock bashing with the bike (forest trails) i desided to get a drink from a store (lidl, german i think) well, after the forest ride (5km or so) im on the road on the way to this store... and my crank just flies off while pedalling! theres this hex bolt that holds it in and i guess that came loose... its a truvative firex... oh its the crank with out the chain rings... whats going on here??? should i check for somthing else that might come off?

thanks, lol scared the ***** outa me, oh and now its knocking (i can feel/hear it) a bit every coplete cycle/pedal (revaloution)
diff_lock2 is offline  
Old 06-26-06, 12:10 PM
  #2  
KevinF
Keep on climbing
 
Join Date: Apr 2004
Location: Marlborough, Massachusetts
Posts: 2,179

Bikes: 2004 Calfee Tetra Pro

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 21 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
If the crank-arm fixing bolt was loose enough to allow the crank arm to come right off during a ride, then you've probably ruined the crank-arm / bottom-bracket interface as well. In other words, you might be able to put the crank-arm back on, but you'll never get it properly tight again -- it'll just keep working its way loose. That's probably what the "knocking" sound you refer to is -- you're flexing the crank-arm against the bottom bracket spindle and ruining it some more.

If I were you, I'd toss the crank arm and bottom bracket and install new ones.
KevinF is offline  
Old 06-26-06, 06:03 PM
  #3  
Waldo
Zippy Engineer
 
Waldo's Avatar
 
Join Date: Jan 2003
Location: IN
Posts: 1,801

Bikes: Bianchi 928, Bianchi Pista Concept 2004, Surly Steamroller, 1998 Schwinn Factory Team Homegrown, 1999 Schwinn Homegrown Factory, 2000 Schwinn Panther, Niner EMD9

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
A new BB is not usually necessary. Hardened steel spindle vs. alu crankarm is no contest. You should be able to snag a new arm relatively inexpensively at your local shop.
Waldo is offline  
Old 06-26-06, 06:10 PM
  #4  
vw addict
Senior Member
 
vw addict's Avatar
 
Join Date: Jan 2006
Location: East coast
Posts: 2,671

Bikes: Specialized Tarmac Expert, Cannondale R700, Specialized Langster, Iron Horse Hollowpoint Team, Schwinn Homegrown

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Call Truvative, they will gladly send you replacements. There was a tech bulliten about the Truvative splines interface and how to properly torque it. I have seen many come apart.
vw addict is offline  
Old 06-26-06, 08:05 PM
  #5  
Waldo
Zippy Engineer
 
Waldo's Avatar
 
Join Date: Jan 2003
Location: IN
Posts: 1,801

Bikes: Bianchi 928, Bianchi Pista Concept 2004, Surly Steamroller, 1998 Schwinn Factory Team Homegrown, 1999 Schwinn Homegrown Factory, 2000 Schwinn Panther, Niner EMD9

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Ah, good call. Forgot that they were hooking people up on those.
Waldo is offline  
Old 06-26-06, 10:18 PM
  #6  
seely
The Rabbi
 
seely's Avatar
 
Join Date: Apr 2004
Posts: 5,125
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Firex is most likely square taper, in which case the recall/warranty does not apply.
seely is offline  
Old 06-27-06, 03:51 AM
  #7  
cs1
Senior Member
 
cs1's Avatar
 
Join Date: Feb 2004
Location: Clev Oh
Posts: 6,931

Bikes: Specialized, Schwinn

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Liked 2 Times in 2 Posts
Originally Posted by KevinF
If the crank-arm fixing bolt was loose enough to allow the crank arm to come right off during a ride, then you've probably ruined the crank-arm / bottom-bracket interface as well. In other words, you might be able to put the crank-arm back on, but you'll never get it properly tight again -- it'll just keep working its way loose. That's probably what the "knocking" sound you refer to is -- you're flexing the crank-arm against the bottom bracket spindle and ruining it some more.

If I were you, I'd toss the crank arm and bottom bracket and install new ones.
+1

Tim
cs1 is offline  
Old 06-27-06, 07:19 AM
  #8  
diff_lock2
Senior_Member2
Thread Starter
 
diff_lock2's Avatar
 
Join Date: Apr 2006
Location: Finlando NOT: Orlando, Fl
Posts: 1,694

Bikes: Beater + Nishiki Bigfoot X-29

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
well obiosly(sp) im going to check up on warranty, and then make the lbs take a look at it and see what went wrong... lol first my seat post and now the crank... maybe i should have gone with the hoss... lol
diff_lock2 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Fuse4
BMX
4
11-16-07 05:01 AM
simplyred
Road Cycling
3
11-16-05 10:51 PM
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.