Is this frame fixable?
09-19-11 | 08:47 PM
#1
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From: Kalamazoo
Is this frame fixable?
Tonight, when I arrived at the park for our weekly club ride, someone had left some bike parts with a handmade sign stating "FREE", leaning against a fence. In addition to the assorted tubes and tires, (which I also grabbed), was this Cannondale CAAD4 R3000 frame. I believe it to a model year 2000.
The issue with the frame appears to be a sizable dent in the top tube. It looks like something fell on it.
Opinions?
The issue with the frame appears to be a sizable dent in the top tube. It looks like something fell on it.
Opinions?
__________________
Carbon: Fuji SL2.1 Di2.......Aluminum: Cannondale Synapse 105........Steel: Vintage Specialized Sirrus
...
Carbon: Fuji SL2.1 Di2.......Aluminum: Cannondale Synapse 105........Steel: Vintage Specialized Sirrus
...
09-19-11 | 09:05 PM
#3
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Ignore the dent. Use it as a place to stick a half-eaten Power Bar. It's not worth repairing, and a TT doesn't get stressed all that much, so even though it may look gawd-awful, it's probably not going to fail anytime soon.
Last edited by 753proguy; 09-19-11 at 09:07 PM. Reason: spelling (once again.....).
09-19-11 | 09:38 PM
#4
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From: Chattanooga
Bikes: '93 Bridgestone RB-1, '91 Specialized Allez Epic, '85 Raleigh Team Pro, '78 Andre Bertin, early '90s F. Moser Leader AX , '85 Centurion Equipe, '98 Litespeed Tuscany, '89 Klein Quantum, '80 Nishiki Superbe, '83 Peckham, '84 Fuji Opus III
I would find it irresistible, trying to fix that. Since it's aluminum, it probably will be weakened but the bends are gentle in nature. I'd try to fill the tube with water, seal it off and freeze. Repeat, if necessary, until it is fully expanded to normal. Might work. Little to lose.
Best,
J
Best,
J
09-19-11 | 09:39 PM
#5
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From: Sacramento, CA
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Facial Reconstructive Surgery..........
The reason the frame cracked is because of the heat treating that was done to make the very thin tubing stronger (higher yield strength and higher fatigue strength), so it retains alignment and lasts longer during hard use.
However, heat-treated aluminum cannot be dented without introducing precurser cracks, and is thus no longer malleable.
Any welding done after heat-treating will return the metal to it's original, weak state.
If this frame doesn't use butted tubing, there is some excess of strength along the mid-sections of each tube, and the heat treating was done firstly to strengthen the ends, where the stresses are highest. Whether or not the middle of each tube is thick enough to retain sufficient strength after welding would be very hard to calculate however, and cracks anywhere in a heat-treated frame tend to spread rapidly in brittle (sometimes spectacular) fashion.
I've seen and heard Cannondale frames snap in two, with a bang, the metal is that brittle!
However, heat-treated aluminum cannot be dented without introducing precurser cracks, and is thus no longer malleable.
Any welding done after heat-treating will return the metal to it's original, weak state.
If this frame doesn't use butted tubing, there is some excess of strength along the mid-sections of each tube, and the heat treating was done firstly to strengthen the ends, where the stresses are highest. Whether or not the middle of each tube is thick enough to retain sufficient strength after welding would be very hard to calculate however, and cracks anywhere in a heat-treated frame tend to spread rapidly in brittle (sometimes spectacular) fashion.
I've seen and heard Cannondale frames snap in two, with a bang, the metal is that brittle!
09-19-11 | 09:53 PM
#6
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09-19-11 | 10:01 PM
#7
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From: Lancaster,CA the desert north of Los Angeles
Bikes: 84' Ciocc, 79' Shogun 1000, 76' KHS Gran Sport, 96' Schwinn Super Sport,
I hope you have not stopped listening to suggestions. Look inside the seat tube and the head tube, think of a way to seal off one side and fill from the other with epoxy and microballoons. It will add weight but you won't have to worry about failure. Measure the size of the tube and fgure out the volume to see how much epoxy and microballoons you will need. Mix the microB to the maximum ratio with the least amount of epoxy. The end result is a little heavyer then foam but much stronger.
Last edited by Alan Edwards; 09-20-11 at 08:34 AM.
09-19-11 | 10:42 PM
#9
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From: Alabama
Bikes: 1981 Motobecane Mirage, 1987 Peugeot Tourmalet, EZ Racer recumbent, 1994 Trek Singletrack 930, 1999 Canndondale SuperV500SL, 2001 Gunnar Crosshairs , 2009 Gunnar Roadie.
Rode a frame with a bend just almost exactly like that in that almost exact position for two years. It was a mountain bike however, and I road it almost completely offroad. Never had any problem with it whatsoever. Sold it to a co-worker who rides it still. I did give him a sweet deal on it because of the dent.
09-20-11 | 04:30 AM
#11
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From: Thunder Bay, Ontario, Canada - burrrrr!
Bikes: 1958 Rabeneick 120D, 1968 Legnano Gran Premio, 196? Torpado Professional, 2000 Marinoni Piuma
Ride it the way it is, just as I do with perhaps the favorite rider in my collection, my Specialized Junker II. And though I do not do this, you can regale your friends and acquaintances with the how the crash damage occurred and you lived through it. Should be worth a beer or two at the pub with each telling. And each telling can embellish the last:-)
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09-20-11 | 04:37 AM
#12
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From: Hurricane Alley , Florida
Bikes: Treks (USA), Schwinn Paramount, Schwinn letour,Raleigh Team Professional, Gazelle GoldLine Racing, 2 Super Mondias, Carlton Professional.
Fill the top tube with expanding foam to give it support. Then fill the dent with all metal body filler, paint it and ride it like you stole it......
09-20-11 | 07:02 AM
#13
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From: Locust NC
Bikes: 1992, Cannondale R900. Schwinn Prologue. 1991 Paramount pdg
I repaired a CAAD three with almost same dent.
I drilled a 1/4"hole on bottom of tube and used a brass rod and small hammer and tapped it for two hours and it all came out.
Ed
I drilled a 1/4"hole on bottom of tube and used a brass rod and small hammer and tapped it for two hours and it all came out.
Ed
09-20-11 | 07:13 AM
#15
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From: Pearland, Texas
Bikes: Cannondale, Trek, Raleigh, Santana
Tonight, when I arrived at the park for our weekly club ride, someone had left some bike parts with a handmade sign stating "FREE", leaning against a fence. In addition to the assorted tubes and tires, (which I also grabbed), was this Cannondale CAAD4 R3000 frame. I believe it to a model year 2000.
The issue with the frame appears to be a sizable dent in the top tube. It looks like something fell on it.
Opinions?
The issue with the frame appears to be a sizable dent in the top tube. It looks like something fell on it.
Opinions?
Brad
09-20-11 | 07:36 AM
#16
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From: NJ, NYC, LI
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
People love the hammered look on fenders, so why not hammered frames? Hand me that baseball bat, please, and stand back.
09-20-11 | 07:47 AM
#17
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something like Angioplasti? then maybe a stint?
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk
09-20-11 | 07:55 AM
#18
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From: Ffld Cnty Connecticut
Bikes: Old Steelies I made, Old Cannondales
I would find it irresistible, trying to fix that. Since it's aluminum, it probably will be weakened but the bends are gentle in nature. I'd try to fill the tube with water, seal it off and freeze. Repeat, if necessary, until it is fully expanded to normal. Might work. Little to lose.
Best,
J
Best,
J
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09-20-11 | 07:57 AM
#19
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From: Ffld Cnty Connecticut
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And include a long story about what caused the dent ...... crashing while trying to escape a grizzly bear .... or maybe the dent was from hitting the bear with your bike in self defense.
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09-20-11 | 10:21 AM
#21
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From: Locust NC
Bikes: 1992, Cannondale R900. Schwinn Prologue. 1991 Paramount pdg
Ed
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