Rear Derailleur R9150 Di2 - Bracket Axle Bolt
04-11-20, 10:18 AM
#1
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Rear Derailleur R9150 Di2 - Bracket Axle Bolt
Hi,
I was inspecting my rear derailleur very closely (Dura Ace R9150) and noticed that the inside of the bracket axle bolt has cracks. I have no idea how this happened as the RD is almost brand new. However, the outside end of the bolt shows no signs of cracks
. Should I be concerned?
Inside of axle bolt with cracks
Outside end of axle bolt perfect - no signs of cracks
I was inspecting my rear derailleur very closely (Dura Ace R9150) and noticed that the inside of the bracket axle bolt has cracks. I have no idea how this happened as the RD is almost brand new. However, the outside end of the bolt shows no signs of cracks
. Should I be concerned?Inside of axle bolt with cracks
Outside end of axle bolt perfect - no signs of cracks
04-11-20, 02:25 PM
#2
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Since I now have plenty of time because about the only time I go out of the house is for my daily ride, I went out and looked at my 2 month old Ultegra Di2. It looks very similar to yours. I believe it just a remnant from the cold forming process I'm guessing they use to manufacture the screws.
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04-11-20, 03:01 PM
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I wouldn't worry about it. First, they might not even be cracks - it might just be residue. Also, the cylindrical shape is exceptionally strong - if the bolt were bored all the way through, it would still be more than strong enough for the application.
04-11-20, 05:41 PM
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Seen that before on lots of bolts. No biggie
04-12-20, 09:33 PM
#5
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Since I now have plenty of time because about the only time I go out of the house is for my daily ride, I went out and looked at my 2 month old Ultegra Di2. It looks very similar to yours. I believe it just a remnant from the cold forming process I'm guessing they use to manufacture the screws.
https://youtu.be/-CT3230Vszw
https://youtu.be/-CT3230Vszw
04-12-20, 09:33 PM
#6
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Thanks for the reassurance!
