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 07-11-10, 02:33 PM   #1
bthomas515
Senior Member
Thread Starter
 
Join Date: Aug 2009
Bikes:
Posts: 72
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Why does my chain keep braking?

I bought a Cannondale and rode it for about 150 miles without any problem, and then switched over the SRAM group to my Blue. After the swap, the bike rides for about a mile or two and then suddenly my chain breaks. This has happened about three times and I have tried all sorts of remedies and none of them seem to work. It seems to happen when I put stress on the chain, such as going uphill or pedaling harder. I was just wondering if any one knew what may cause this or have had this problem?
Thanks
bthomas515 is offline   Reply With Quote
Old 07-11-10, 02:45 PM   #2
geo8rge
Senior Member
 
Join Date: Mar 2006
Bikes:
Posts: 2,013
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I would guess the chain is defective.
__________________
2000 Montague CX, I do not recommend it, but still ride it.
Strida 3, I recommend it for rides < 10mi wo steep hills.
2006 Rowbike 720 Sport, I recommend it as an exercise bike.
1996 Birdy, Recommend.
Wieleder CARiBIKE (folding), decent frame.
geo8rge is offline   Reply With Quote
Old 07-11-10, 02:54 PM   #3
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 29,395
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 74 Post(s)
A defective chain may break once, but the odds of a defective chain causing multiple breaks are extremely low.

need to know more.

Is it a Sram or other brand chain?
Is it breaking at the same or different places?
Are you closing it with a new connector link, or the same one, or simply using a chain tool?
Are plates cracking, twisting, or falling off the end of the pin on one side, then bending open under load?
Did you correctly measure the chain so it clears the large/large combination plus at least one inch?

Even without seeing your answers, I suspect your problem is related to how you're closing the chain, and that shifting is forcing the plates over the ends of the pin.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is online now   Reply With Quote
Old 07-11-10, 04:43 PM   #4
cny-bikeman 
Mechanic/Tourist
 
Join Date: Apr 2007
Location: Syracuse, NY
Bikes: 2008 Novara Randonee - love it. Would have more bikes if I had time to ride them all. Previous bikes: 1968 Motobecane Mirage, 1972 Moto Grand Jubilee (my fav), Jackson Rake 16, 1983 C'dale ST500.
Posts: 6,234
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Agreed. The first suspect would be incorrect installation. The odds of a chain failing that drastically that many times is nil. Unless you have proper tools and detailed instructions that you are clear about I would have a shop install it.
cny-bikeman is offline   Reply With Quote
Old 07-11-10, 06:47 PM   #5
garage sale GT
Banned
 
Join Date: May 2009
Bikes:
Posts: 2,078
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Have you cleaned your chain with anything unusual? I had several sideplates crack on a chain just from the tension caused by the pins when I took it in from the snow and cleaned it with oven cleaner.
garage sale GT is offline   Reply With Quote
Old 07-11-10, 07:16 PM   #6
Shimagnolo
Senior Member
 
Shimagnolo's Avatar
 
Join Date: May 2008
Location: Zang's Spur, CO
Bikes:
Posts: 7,414
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
I have been using only SRAM chains for some years now.
I've never has the slightest problem with them.
Shimagnolo is offline   Reply With Quote
Old 07-12-10, 07:47 AM   #7
rogerstg
Fred-ish
 
rogerstg's Avatar
 
Join Date: Aug 2007
Location: Rhode Island
Bikes:
Posts: 1,800
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by geo8rge View Post
I would guess the chain is defective.
+1
I had this happen with a Sram 9s; 3 breaks within 300 miles - new chain solved the problem. FWIW, it's the only chain breakage I've had on modern equipment in the last decade.
rogerstg is offline   Reply With Quote
Old 07-12-10, 10:45 AM   #8
blamp28
Bikaholic
 
blamp28's Avatar
 
Join Date: Dec 2006
Location: Western, Michigan
Bikes: Trek Fuel 90, Giant OCR, Rans Screamer Tandem
Posts: 1,465
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by rogerstg View Post
+1
I had this happen with a Sram 9s; 3 breaks within 300 miles - new chain solved the problem. FWIW, it's the only chain breakage I've had on modern equipment in the last decade.
I had exactly the same experience last summer with my son's race bike. Must have been a bad batch.
blamp28 is offline   Reply With Quote
Old 07-12-10, 10:57 AM   #9
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)
The Op swapped his chain to his new bike. He either

1) Failed to use a new 10s powerlock (assuming it's 10s)
2) Repinned the chain (you can't do this)
3) Chain failure is a coincidental to swapping it and it is masking a sever wear issue
4) OP does not know how to shift properly coupled with any combination of the above
operator 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 10:21 AM.