Tapping in a new th...
 

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Tapping in a new thread for a disc

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Posts: 17
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I had to drill out a rotor bolt a while ago, probably just over a year. Discs quite warped. I’ve definitely crashed over winter a few times, but is having 5 bolts likely to cause the disc to warp?

Providing I do it well, can anyone see any issues arising from tapping in a new thread into the hub? Alternatively, has anyone just put a nut on the other side of the disc? Or I could just true the disc and see if it remains true? Any thoughts? 


 
Posted : 20/03/2025 6:48 pm
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I’d be not worrying about that. Three would be fine in my house 🙂 

YMMV


 
Posted : 20/03/2025 6:58 pm
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How much material is left? I'd be considering a helicoil thread repair


 
Posted : 20/03/2025 7:02 pm
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5 bolts should be fine but a helicoil would be the best fix


 
Posted : 20/03/2025 7:40 pm
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Personally I'd helicoil it , that might just be my OCD but I wouldn't worry about the functionality of it, weight weenies and racers have ran their rotors with just 3 bolts.


 
Posted : 20/03/2025 7:43 pm
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Try a nut for simplicity and see if it solves the warping


 
Posted : 20/03/2025 7:44 pm
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Helicoil can be quite tricky in modern hubs, you often have very little material spare. But drilling through and fitting a longer bolt and nut (or drilling the hole deeper and tapping it and using a long bolt) can often work. In some cases you already have a long, fully threaded hole and literally just need to fit a longer bolt to reach the undamaged thread (especially if you've fitted excessively short bolts, don't arsk me how I knows, I just knows)

But it's not very likely to warp a risc as others said. Ther'es an argument that 5 is worse than 3 because of the unevenness but tbh with most discs I doubt it's an issue at all. Sometimes, discs just bend- they're thin and stressed.


 
Posted : 20/03/2025 7:49 pm
fasthaggis reacted
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Thanks for responses. I’ll assume I’ve either bent the disc crashing or from throwing my bike in the back of the car. Might just true the rotor, watch and wait. 


 
Posted : 21/03/2025 9:32 am

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