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 03-10-05, 12:27 AM   #1
sirwilliamjr
Member
Thread Starter
 
Join Date: Jan 2005
Bikes:
Posts: 49
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Loose crank

I just had work done on my mountain bike (Trek 4500, about 3 yrs old) because the chainrings were coming loose from the crank. I think it was a loose spider ring maybe? Anyway, they tightened it up for me and charged 10 bucks and everything was good. 12 miles of riding later (after a few weeks) my right side crank comes loose. The hex bolt holdin on the crank (I assume that's what it does) is really loose. So I'm thinking that it's the LBS's fault because I've ridden the bike for years w/ no trouble, then they do some work (assuming they took the crank off to tighten the lockring) and it almost falls off 12 miles later. So I guess I'm kinda complaining, but I also want to know what to do. I'd take it to the shop, but that's a hassle and I guess it might not be their fault, so what do I need to do to fix it myself. Can I just tighten it back, or do I need to worry about sand/dirt having gotten inside somewhere, and then take it all apart, clean it, and put it back together? I pretty much stopped riding when I realized something was wrong, but it was a pretty sandy trail. And, can I just tighten the bolt down real tight, or does it really need to be a specific torque? Thanks, and sorry for the long message.

-Will
sirwilliamjr is offline   Reply With Quote
Old 03-10-05, 09:04 AM   #2
iowarose
Senior Member
 
iowarose's Avatar
 
Join Date: Dec 2004
Location: Iowa City
Bikes:
Posts: 295
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Speaking from the customer's perspective, I would certainly take it back to the LBS and point it out to them.
iowarose is offline   Reply With Quote
Old 03-10-05, 09:11 AM   #3
trlpmp
Reckless Rider
 
trlpmp's Avatar
 
Join Date: Nov 2004
Location: Chicago
Bikes: 2 Konas, 1 Santa Cruz, 1 Surly, 1 Cannondale, 1 Schwinn
Posts: 29
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Tighten the bolt down with wrist-not arm. If it comes loose again tighten it a little more than the last time.
trlpmp is offline   Reply With Quote
Old 03-10-05, 09:23 AM   #4
sydney
Senior Member
 
sydney's Avatar
 
Join Date: Jan 2004
Bikes:
Posts: 9,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by trlpmp
Tighten the bolt down with wrist-not arm. If it comes loose again tighten it a little more than the last time.
And you can get 35 foot pounds that way?? It needs to be tight enough that is does not come loose again.That may have been the issue to begin with. Loosening while riding it can hose the crankarm interface.
sydney is offline   Reply With Quote
Old 03-10-05, 09:23 AM   #5
powers2b
Listen to me
 
powers2b's Avatar
 
Join Date: Nov 2004
Location: Lexus Texas
Bikes:
Posts: 2,789
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Go back to the shop and ask for your $10 back.
They are liable for work that they do to your bike and would rather give your money back than face a bad image and/or lawsuit.
Enjoy
powers2b is offline   Reply With Quote
Old 03-10-05, 09:25 AM   #6
sydney
Senior Member
 
sydney's Avatar
 
Join Date: Jan 2004
Bikes:
Posts: 9,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by sirwilliamjr
I just had work done on my mountain bike (Trek 4500, about 3 yrs old) because the chainrings were coming loose from the crank. I think it was a loose spider ring maybe? Anyway, they tightened it up for me and charged 10 bucks and everything was good. 12 miles of riding later (after a few weeks) my right side crank comes loose. The hex bolt holdin on the crank (I assume that's what it does) is really loose. So I'm thinking that it's the LBS's fault because I've ridden the bike for years w/ no trouble, then they do some work (assuming they took the crank off to tighten the lockring) and it almost falls off 12 miles later. So I guess I'm kinda complaining, but I also want to know what to do. I'd take it to the shop, but that's a hassle and I guess it might not be their fault, so what do I need to do to fix it myself. Can I just tighten it back, or do I need to worry about sand/dirt having gotten inside somewhere, and then take it all apart, clean it, and put it back together? I pretty much stopped riding when I realized something was wrong, but it was a pretty sandy trail. And, can I just tighten the bolt down real tight, or does it really need to be a specific torque? Thanks, and sorry for the long message.

-Will
I'd take it back.You can retighten it. Problem is that having it loosen up while riding could have damaged the crank.When that happens, it will often never stay tight.
sydney is offline   Reply With Quote
Old 03-10-05, 09:50 AM   #7
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
They charged 10 bucks to tighten a couple screws...? Or am I missing something.
operator is offline   Reply With Quote
Old 03-10-05, 11:03 AM   #8
peripatetic
Senior Member
 
peripatetic's Avatar
 
Join Date: Oct 2004
Location: NYC
Bikes: All 70s and 80s, only steel.
Posts: 2,124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by sydney
I'd take it back.You can retighten it. Problem is that having it loosen up while riding could have damaged the crank.When that happens, it will often never stay tight.
Exactly this happened to me. I rode on a loose crank maybe 1/2 mile total. Took it in, the mechanic took off the crank and showed me how the soft metal of the crank had worn out by rubbing loosely against the harder-metal spindle. I had to replace the crank and pay for the labor. Totally ruined my day. Take it back to the shop and make sure that the crank isn't really messed up. If it is, they should replace it for free and tighten everything down better.
peripatetic is offline   Reply With Quote
Old 03-10-05, 11:22 AM   #9
midgie
Senior Member
 
midgie's Avatar
 
Join Date: Jan 2005
Location: Illinois
Bikes: 2004 Raliegh Retro Glide 7(green of course), 2005 Stingray Pea Picker 2005 Specialized Hardrock 2014 Trek Crossfit
Posts: 1,015
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Definately take it back to the shop. If you try to tighten it your self, and have to do this numerous times, with the same outcome, and then you take it back to the shop . They will not stand behind it. Riding a loose crank will round out the crank and possibly the the BB spindle. Then you'll have to replace both. Crank bolts should be tightened with a torque wrench, to insure that the arm is on all the way, and that it will stay there. IMO
__________________
We're gonna have the hap, hap, happiest Christmas since Bing Crosby tap-danced with Danny ****ing Kaye.~Clark Griswold
midgie is offline   Reply With Quote
Old 03-10-05, 11:31 PM   #10
sirwilliamjr
Member
Thread Starter
 
Join Date: Jan 2005
Bikes:
Posts: 49
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Well, I took it by the shop today and talked to the mechanics. They said that it isn't uncommon for crank bolts to come loose once you've loosened them the first time. Doesn't make a whole lot of sense to me, but they were nice about it and tightened it up for me (for free). I asked if it could have gotten messed up riding w/ it loose, but they said the splines on mine (don't know what type of cranks I have) are really hard to mess up and it should be fine. I took his word for it, and I rode it a little and it seemed fine, so I'm happy. I guess time will tell if I've been screwed though... Thanks everyone for the help.

-Will
sirwilliamjr is offline   Reply With Quote
Old 03-11-05, 12:27 AM   #11
ivan_yulaev
Senior Member
 
Join Date: Mar 2004
Location: San Diego, CA
Bikes: See sig.
Posts: 1,651
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Maybe use some blue loctite? Prevent from happening again.
ivan_yulaev 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 04:07 AM.