Shimano Crankset Recall: DuraAce and Ultegra

853okg said:
I’m opposed to bonding, but theoretically there’s nothing wrong with it. Lots of bonded components in other fields are more stressed and at least as mission critical as a crankset, and do fine. These were defective, hence the dates issued. Still, I don’t like it. And we’re talking about a LOT of product. It’s a nightmare.
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Agreed. Back in the day I had a Vitus 979 frame that was glued together. It wasn't stiff but it was strong & durable. Some racecar frames have been built that way. Also, many carbon forks have aluminum dropouts which are glued to the carbon. Properly built, those can last a lifetime.
 
MRC01 said:
Agreed. Back in the day I had a Vitus 979 frame that was glued together. It wasn't stiff but it was strong & durable. Some racecar frames have been built that way. Also, many carbon forks have aluminum dropouts which are glued to the carbon. Properly built, those can last a lifetime.
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No, they weren’t stiff but the necessity of a stiff frame is a myth. While the overweight, middle aged editors of Bicycling! magazine panned the 979 (and swooned over the 3 Rensho) a young Sean Kelly racked up a gaudy list of palmares against the fastest road sprinters in the world on his. And Greg LeMond’s bonded TVT stood up just fine while winning the TdF and World Championship.
 
Vern_in_IL said:
It's pretty common knowledge that the mashing of pedals is a pretty good way to invite all sorts of knee issues and pain.
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So again I'm not a road rider but I always rode my hardtail on the street for years and years. That bike got stolen and I didn't replace it for a long time. I finally got a new mountain bike and one thing I noticed was knee pain. Never had that before. I bought a set of clipless pedals like I used to have an the knee pain went away.
 
MrQuackers said:
I am recalling the Vitus bike frames coming back to the shop for repair in the 80's
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Do you remember what they came back to the shop for? Back in the 1980s, the worst crash I had on mine was at about 40 mph. The fork was ruined (as expected) but the frame was fine and went for several more years and many thousands of miles before I finally sold that bike, still in great condition.
 
MRC01 said:
Do you remember what they came back to the shop for? Back in the 1980s, the worst crash I had on mine was at about 40 mph. The fork was ruined (as expected) but the frame was fine and went for several more years and many thousands of miles before I finally sold that bike, still in great condition.
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I think it was in the frame around the bb
 
They (and the Italian made Alan) held up pretty well but very few let go. Recall, they were screwed as well as glued. No LBS fixed them, unless you worked for Harry Havnoonian in Philly. A lot of people broke them by prying the cast seat lug open. The carbon tubes, naturally, were more fragile.
 
853okg said:
They (and the Italian made Alan) held up pretty well but very few let go. Recall, they were screwed as well as glued. No LBS fixed them, unless you worked for Harry Havnoonian in Philly. A lot of people broke them by prying the cast seat lug open. The carbon tubes, naturally, were more fragile.
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My bad, probably another brand that was press fit/glued

I was just assembler and all the quick repairs kid
 
My Ultegra 600 cranks are old enough to be forged.
I've broken forged cranks, Campy Record and old DuraAce, both fatigue failures at a little over 70k miles.
 
zzyzzx said:
Found a YouTube video on this. Cranksets should not be hollow!
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I would put it differently. Crank arms should not be glued together. It is possible to fabricate each crankarm from a single piece of metal/alloy, and make it hollow, without any seams or glue.
 
MRC01 said:
I would put it differently. Crank arms should not be glued together. It is possible to fabricate each crankarm from a single piece of metal/alloy, and make it hollow, without any seams or glue.
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The original Bullseye crankset. It’s a design widely used today, only dumbed down for mass production.
 
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