How to remove C'dale eccentric bottom bracket?
09-17-14, 07:51 AM
#1
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How to remove C'dale eccentric bottom bracket?
I want to remove the eccentric shell to clean and regrease everything before reassembly of the tandem, its a 2008 RT3 cannondale
How do I remove the eccentric shell from the frame?
The cranks are off, the eccentric turns freely, but I can't slide it on either side to remove it.
do I have to unscrew the bearings from the eccentric first?
Thank you!
How do I remove the eccentric shell from the frame?
The cranks are off, the eccentric turns freely, but I can't slide it on either side to remove it.
do I have to unscrew the bearings from the eccentric first?
Thank you!
09-17-14, 11:12 AM
#2
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My 2007 Cannondale Tandem has the "double-wedge" eccentric, which I am almost certain you will have.
As designed by Cannondale, tightening the hex head cap screw, opposite the timing chain side, will tighten both wedges at the same time. A very secure design. The rub is when you want to loosen both wedges to adjust or remove the eccentric. The hex head cap screw is secured to the wedge with an internal "c" ring. Loosening the screw will push against both wedges to loosen the eccentric, as long as the "c" ring is in place.
My experience was that the groove in the wedge for the internal "c" ring was easily "rounded" off, and once that happened, I could not get a "c" ring to stay in place for the hex head screw to push against. I was stuck and both wedges can be very difficult to loosen. I would suggest that you loosen the hex head screw and gently tap to remove the wedge on the timing chain side. Then gently tap the body of the eccentric toward the timing chain side. This is the best option that I know of.
My solution was to go to Tandems East and purchase from Mel his modified "double-wedge" eccentric for the Cannondale. He was willing to refund part of my purchase price when I returned my old eccentric to him as a "core" for him to "remanufacture". That was four years ago, and he may have modified his policy.
There are other upgrade eccentrics that you can purchase for more money, but I found this to be the best bang for my buck.
Good luck, and hope to see you on the road!
As designed by Cannondale, tightening the hex head cap screw, opposite the timing chain side, will tighten both wedges at the same time. A very secure design. The rub is when you want to loosen both wedges to adjust or remove the eccentric. The hex head cap screw is secured to the wedge with an internal "c" ring. Loosening the screw will push against both wedges to loosen the eccentric, as long as the "c" ring is in place.
My experience was that the groove in the wedge for the internal "c" ring was easily "rounded" off, and once that happened, I could not get a "c" ring to stay in place for the hex head screw to push against. I was stuck and both wedges can be very difficult to loosen. I would suggest that you loosen the hex head screw and gently tap to remove the wedge on the timing chain side. Then gently tap the body of the eccentric toward the timing chain side. This is the best option that I know of.
My solution was to go to Tandems East and purchase from Mel his modified "double-wedge" eccentric for the Cannondale. He was willing to refund part of my purchase price when I returned my old eccentric to him as a "core" for him to "remanufacture". That was four years ago, and he may have modified his policy.
There are other upgrade eccentrics that you can purchase for more money, but I found this to be the best bang for my buck.
Good luck, and hope to see you on the road!
09-17-14, 01:36 PM
#3
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That is what I want to do, both wedges are loose, eccentric turns freely, but the shell will not come out, do I have to remove the bearings first so it wil come out?
should it just slide out of the timing chain side?
Edit, ok, got it, removed the BB cups, a few taps on the eccentric shell with a rubber mallet and it came out.
Interesting to see the weight of a M/S bare cannondale frame, heavier than I expected
should it just slide out of the timing chain side?
My 2007 Cannondale Tandem has the "double-wedge" eccentric, which I am almost certain you will have.
As designed by Cannondale, tightening the hex head cap screw, opposite the timing chain side, will tighten both wedges at the same time. A very secure design. The rub is when you want to loosen both wedges to adjust or remove the eccentric. The hex head cap screw is secured to the wedge with an internal "c" ring. Loosening the screw will push against both wedges to loosen the eccentric, as long as the "c" ring is in place.
My experience was that the groove in the wedge for the internal "c" ring was easily "rounded" off, and once that happened, I could not get a "c" ring to stay in place for the hex head screw to push against. I was stuck and both wedges can be very difficult to loosen. I would suggest that you loosen the hex head screw and gently tap to remove the wedge on the timing chain side. Then gently tap the body of the eccentric toward the timing chain side. This is the best option that I know of.
My solution was to go to Tandems East and purchase from Mel his modified "double-wedge" eccentric for the Cannondale. He was willing to refund part of my purchase price when I returned my old eccentric to him as a "core" for him to "remanufacture". That was four years ago, and he may have modified his policy.
There are other upgrade eccentrics that you can purchase for more money, but I found this to be the best bang for my buck.
Good luck, and hope to see you on the road!
As designed by Cannondale, tightening the hex head cap screw, opposite the timing chain side, will tighten both wedges at the same time. A very secure design. The rub is when you want to loosen both wedges to adjust or remove the eccentric. The hex head cap screw is secured to the wedge with an internal "c" ring. Loosening the screw will push against both wedges to loosen the eccentric, as long as the "c" ring is in place.
My experience was that the groove in the wedge for the internal "c" ring was easily "rounded" off, and once that happened, I could not get a "c" ring to stay in place for the hex head screw to push against. I was stuck and both wedges can be very difficult to loosen. I would suggest that you loosen the hex head screw and gently tap to remove the wedge on the timing chain side. Then gently tap the body of the eccentric toward the timing chain side. This is the best option that I know of.
My solution was to go to Tandems East and purchase from Mel his modified "double-wedge" eccentric for the Cannondale. He was willing to refund part of my purchase price when I returned my old eccentric to him as a "core" for him to "remanufacture". That was four years ago, and he may have modified his policy.
There are other upgrade eccentrics that you can purchase for more money, but I found this to be the best bang for my buck.
Good luck, and hope to see you on the road!
Interesting to see the weight of a M/S bare cannondale frame, heavier than I expected
Last edited by Eddie50; 09-17-14 at 02:20 PM.
09-17-14, 11:09 PM
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Just got home from work (midnight local time). Glad to read that you got the eccentric out. Sounds like your home free. Have fun!
09-18-14, 12:37 AM
#5
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I work in a shop that sells Cannondales and a couple of other bike brands. We joke that the big rubber mallet in the workshop is only for Cannondale bikes because we seem to need to use it to do any major task on any Cannondale frame (removing Hollowgram crank axles, Lefty fork tubes, eccentric BBs, etc., etc.), but rarely have to use it on any other bikes. Therefore, the general rule of thumb to remove something from a Cannondale is to give it good bash.
09-18-14, 06:19 AM
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Thanks for the tips everyone!
would anybody know the size of the circlip and washer that holds the wedge bolt? I have to change them and put new ones, did not find specs on the cannondale manual.
would anybody know the size of the circlip and washer that holds the wedge bolt? I have to change them and put new ones, did not find specs on the cannondale manual.
09-18-14, 09:10 AM
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I found a match at my local Ace Hardware store, back with the exotic nuts and bolts in the pull out drawers. It was listed on the pull out drawer, as I recall, as an internal "C" ring clip, it was the smallest one in the drawer.
I gave up on the circlip in the wedge and bought a modified eccentric, as I described above. Before I gave up, I purchased a replacement circlip from Cannondale through my local bike shop because I could not find a spec for replacement. Turned out to be the same one available at the hardware store.
I gave up on the circlip in the wedge and bought a modified eccentric, as I described above. Before I gave up, I purchased a replacement circlip from Cannondale through my local bike shop because I could not find a spec for replacement. Turned out to be the same one available at the hardware store.
09-18-14, 10:53 PM
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I want to remove the eccentric shell to clean and regrease everything before reassembly of the tandem, its a 2008 RT3 cannondale
How do I remove the eccentric shell from the frame?
The cranks are off, the eccentric turns freely, but I can't slide it on either side to remove it.
do I have to unscrew the bearings from the eccentric first?
Thank you!
How do I remove the eccentric shell from the frame?
The cranks are off, the eccentric turns freely, but I can't slide it on either side to remove it.
do I have to unscrew the bearings from the eccentric first?
Thank you!
09-21-14, 05:24 PM
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The 'dale setup is not exactly the best/easiest available.
Leave up to Mel K at Tandems East to come up with a better mousetrap!
Peal on~
Rudy and Kay/zonatandem
Leave up to Mel K at Tandems East to come up with a better mousetrap!
Peal on~
Rudy and Kay/zonatandem
07-01-20, 09:27 PM
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Cannondale eccentric bottom bracket, easy out
Unscrew the wedge bolt two turns.
Tap bolt head with punch to loosen threaded wedge. Repeat unscrew.
tap till wobbly.
Cannondale BB removal
Cannondale rod to knock out head wedge.
Unscrew wedge bolt until head wedge pops out or (more likely) bolt pushes out washer and circlip.
Remove bolt.
Insert 3mm diameter x 100mm long rod into threaded wedge hole to press against inside of head wedge.
Tap out head wedge till loose.
See attached photos and Cannondale instructions. 117244.PDF
Tap bolt head with punch to loosen threaded wedge. Repeat unscrew.
tap till wobbly.
Cannondale BB removal
Cannondale rod to knock out head wedge.
Unscrew wedge bolt until head wedge pops out or (more likely) bolt pushes out washer and circlip.
Remove bolt.
Insert 3mm diameter x 100mm long rod into threaded wedge hole to press against inside of head wedge.
Tap out head wedge till loose.
See attached photos and Cannondale instructions. 117244.PDF
