Timing chain adjustment
#1
Thread Starter
Full Member
Joined: Jan 2017
Posts: 441
Likes: 102
From: New England
Bikes: 1987 Cannondale SR600/BioPace, 1991 Cannondale Road Tandem,1994 Giant Iguana MB, 2009 Airnimal Chameleon, 2016 Dahon Vybe C7A
Timing chain adjustment
Was really surprised there are no YouTube videos on adjusting the wedges on a Cannondale to tighten the timing chain. I loosened the wedge bolt a few turns but couldn't get the wedge to rotate (broke a screwdriver tip trying to apply leverage).
Any tips out there on how to free the wedge? Do I have to completely remove the screw, is there anything else to loosen?
Any tips out there on how to free the wedge? Do I have to completely remove the screw, is there anything else to loosen?
#2
Do not pound on the bolt!
Pounding on the bolt will blow out the wedge threads destroying the eccentric.
Loosen/remove the bolt, then use a mallet to pound the body away from the wedge.
Pounding on the bolt will blow out the wedge threads destroying the eccentric.
Loosen/remove the bolt, then use a mallet to pound the body away from the wedge.
#3
Thread Starter
Full Member
Joined: Jan 2017
Posts: 441
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From: New England
Bikes: 1987 Cannondale SR600/BioPace, 1991 Cannondale Road Tandem,1994 Giant Iguana MB, 2009 Airnimal Chameleon, 2016 Dahon Vybe C7A
No worries about pounding on the bolt I'm trying to be careful. The instructions I have found coupled with scarce videos basically say loosen the bolt. Stick a hex wrench in one of the other holes, add leverage, and turn the assembly. Problem is I've loosened the bolt added the leverage and nothing is moving. Was not sure if I missed a step and what exactly should I hit with a mallet?
I'm not trying to remove anything, just rotate to increase the timing chain tension.
I'm not trying to remove anything, just rotate to increase the timing chain tension.
#5
#7
Thread Starter
Full Member
Joined: Jan 2017
Posts: 441
Likes: 102
From: New England
Bikes: 1987 Cannondale SR600/BioPace, 1991 Cannondale Road Tandem,1994 Giant Iguana MB, 2009 Airnimal Chameleon, 2016 Dahon Vybe C7A
I see removing the wedge mentioned also, but is that neccessary?
#8
Is there any chance you are loosening the thread cap, instead of going through it with a 4mm allen and loosening the fixing bolt?
It's been a while since I have done this, but I noticed ours is a bit loose. I will check it out and see if I get any insights.
UPDATE: On our 2004 bike, I couldn't see a thread cap. Whether that means it's a model variant, or I have bad eyes, or it's gone missing, I can't say. All I did was insert a 4mm allen, turn the fixing bolt a couple of turns, and was able to turn the eccentric with an allen (5mm if I recall) in the keyhole. Then I re-tightened the fixing bolt and all seems well.
It's been a while since I have done this, but I noticed ours is a bit loose. I will check it out and see if I get any insights.
UPDATE: On our 2004 bike, I couldn't see a thread cap. Whether that means it's a model variant, or I have bad eyes, or it's gone missing, I can't say. All I did was insert a 4mm allen, turn the fixing bolt a couple of turns, and was able to turn the eccentric with an allen (5mm if I recall) in the keyhole. Then I re-tightened the fixing bolt and all seems well.
Last edited by due ruote; 03-29-21 at 10:29 AM.
#9
Is there any chance you are loosening the thread cap, instead of going through it with a 4mm allen and loosening the fixing bolt?
It's been a while since I have done this, but I noticed ours is a bit loose. I will check it out and see if I get any insights.
UPDATE: On our 2004 bike, I couldn't see a thread cap. Whether that means it's a model variant, or I have bad eyes, or it's gone missing, I can't say. All I did was insert a 4mm allen, turn the fixing bolt a couple of turns, and was able to turn the eccentric with an allen (5mm if I recall) in the keyhole. Then I re-tightened the fixing bolt and all seems well.
It's been a while since I have done this, but I noticed ours is a bit loose. I will check it out and see if I get any insights.
UPDATE: On our 2004 bike, I couldn't see a thread cap. Whether that means it's a model variant, or I have bad eyes, or it's gone missing, I can't say. All I did was insert a 4mm allen, turn the fixing bolt a couple of turns, and was able to turn the eccentric with an allen (5mm if I recall) in the keyhole. Then I re-tightened the fixing bolt and all seems well.
Eccentrics available from Tandems East
#10
Junior Member

Joined: May 2008
Posts: 187
Likes: 20
Bikes: 1997 Specialized Hardrock GX, 2008 Specialized Roubaix Triple 105, 1996 Cannondale RT2000 tandem
Cannondale eccentric frozen?
go down until you see WheelsNT post. I had the same issue, this is the fix.
go down until you see WheelsNT post. I had the same issue, this is the fix.






