Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Recumbent What IS that thing?! Recumbents may be odd looking, but they have many advantages over a "wedgie" bicycle. Discuss the in's and out's recumbent lifestyle in the recumbent forum.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-26-07, 04:34 PM   #1
carcassonne
Senior Member
Thread Starter
 
Join Date: Jan 2007
Bikes:
Posts: 70
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Chain length and derailleur mount break

Folks, recently the derailleur mount on the bike has snapped while climbing a moderately steep hill. The derailleur mount if actually screwed to the frame so it can be replaced easily. Apart from the mount, the chain broke and the derailleur cage was slightly bent. All that went going uphill.

In retrospect I'm sure I'd have some leeway if I'd climb the same hill with the Cannondale badboy in the same very low gear. But with the recumbent I was in direct drive so to speak and since it seems I have some leg power I was just pushing the cranks to get up there when everything snapped.

So my question is, I think it can be possible to be in such a position if the chain is too short. I might have cut the chain to short after adjusting the boom. So when climbing that hill the chain would have exerced too much pressure on the mount. Can this be possible ?

Everyone knows I have an AB HiRacer. I must say that AB did not hesitate one minute in sending me new derailleur mounts. Very good service. To their record they've never seen that kind of incident.

So I think so far that it is my fault by cutting the chain too short. Basically on the recumbent I should have the same leeway (of course this depends on the cogs and chainrings) when climbing uphill than on a regular bike. I should be spinning and grinning going uphill and not be in 'direct drive' of the rear wheel where it feels that every turn of the cranks makes the wheel turn once as in a very steep mountain bike type bump.

Cheers.
carcassonne is offline   Reply With Quote
Old 09-26-07, 07:23 PM   #2
Recumbomatic
Senior Member
 
Join Date: Sep 2006
Location: Aurora, CO
Bikes: 2005 Performer Toscana, Kona Hoo-Ha, RANS V3 steel, RANS City
Posts: 369
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
What chainring were you using? Did you change the boom length recently? When installing a chain, normal procedure is to put the chain on the biggest ring and biggest cog, and adjust length so that the two ends overlap by about an inch.
Recumbomatic is offline   Reply With Quote
Old 09-26-07, 09:33 PM   #3
Trsnrtr
Nefarious Reprobate
 
Trsnrtr's Avatar
 
Join Date: Jun 2002
Location: Central Illinois
Bikes: Colnago CX, Giant Propel, Co-Motion Supremo
Posts: 7,972
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 505 Post(s)
One of the young mechanics at my LBS "optimized" my chain for me one time and I inadvertently shifted big/big on a hill and bent the front idler mount horribly. He had removed two links to try and help me with what he perceived as "too much chain flop."

I do all of my own work and this was a rare case of taking a bike in for a free 500 mile checkup. All I really wanted was for someone else to clean my chain!

Back to the original question, yes, a too short chain can cause some serious damage if you aren't careful.
__________________
Dennis T
Trsnrtr 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 12:57 AM.