Fatal Swan
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Edit - now sorted, thanks for the contributions!
I'm in the process of replacing an Ultegra 6800 chainset with a Dura Ace 9000 on a road bike. I have plenty of experience with Hollowtech II cranks and BBs but I don't think I've come across this issue. There are no complicating compatibility issues - it's a road frame, running a pressfit road BB, so no spacer issues etc. The original Ultegra chainset was fine, I replaced it with another Ultegra chainset which was also fine.
The issue is that with the Dura Ace chainset, when I tighten up the preload bolt it stops turning any further before it actually presses tight against the left crank. So while I can push the crank snugly into position against the BB cups, the preload bolt refuses to tighten to secure it there further. I can't work out why since all the parts are present - I assume that the long plastic preload cap (the original one - the Ultegra and DA ones are the same) has used up all of the internal thread on the axle. The difference between the chainsets must be on the driveside, since when I put the left Ultegra crank on with the Dura Ace driveside, the same thing happens.
I've noticed that other aftermarket preload bolts have a shorter thread than the original one like in the photos below, so I could try that (new bolt or hacksaw??), but I'd like to know if anyone's come across this before?
I'm in the process of replacing an Ultegra 6800 chainset with a Dura Ace 9000 on a road bike. I have plenty of experience with Hollowtech II cranks and BBs but I don't think I've come across this issue. There are no complicating compatibility issues - it's a road frame, running a pressfit road BB, so no spacer issues etc. The original Ultegra chainset was fine, I replaced it with another Ultegra chainset which was also fine.
The issue is that with the Dura Ace chainset, when I tighten up the preload bolt it stops turning any further before it actually presses tight against the left crank. So while I can push the crank snugly into position against the BB cups, the preload bolt refuses to tighten to secure it there further. I can't work out why since all the parts are present - I assume that the long plastic preload cap (the original one - the Ultegra and DA ones are the same) has used up all of the internal thread on the axle. The difference between the chainsets must be on the driveside, since when I put the left Ultegra crank on with the Dura Ace driveside, the same thing happens.
I've noticed that other aftermarket preload bolts have a shorter thread than the original one like in the photos below, so I could try that (new bolt or hacksaw??), but I'd like to know if anyone's come across this before?
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