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I have a 35mm Marz fork with four fender studs (2 per leg). One of the studs has the threads badly buggered. Are these studs bonded into the leg or screwed in? Looking at what schematics I can find it shows the studs in the leg and not a separate part. But I have to think that these studs are suspect to rust, bending, breaking off, threads stripped, etc so I'd be surprised if they aren't removable. But want to check before I go at it.

I'm wondering, since one is already in bad shape, if I don't saw the studs flush and then drill and tap to use bolts instead. It would make taking the front wheel on and off much easier.

'Pound to a penny' they were screwed in by Marzocchi and delivered like that to Ducrappi - hence no separate part.

And I suspect they won't like being removed. You could certainly try a bit of heat, tho'. The alloy of the leg will expand more than the steel of the bolt and a set of vice grips may get you there. You may have to have several attempts. Otherwise, can you re-thread the stud and use double nuts to turn it out?

Drilling and re-tapping is a fair amount of work ...

Although I haven't tried it, there are suggestions that a chemical called alum can safely dissolve steel out of aluminium.

Soaked in penetrating oil for 24 hours. Hit the studs with the flame wrench. Used a stud extractor. All 4 studs sheared. I drilled the studs out and retapped them at M8x1.25. All is well.

Hit the studs with the flame wrench.

Imo, wrong. Heat the fork slider (~ 200°C), not the stud, as aluminum has a higher thermal expansion compared to steel, so the thread shood loosen it's tight fit.
But anyway, you succeeded with your work, congrats.

Hans

Fair point and I agree. Used flame on the alu boss and not directly on the stud. Made nary a difference. I'm sure they are just screwed in but woe be the one who tries to unscrew them.

If someone used a high strength locking sealer, or epoxy, when they put the studs in, you will have to get the aluminum temperature up to 350-400 deg F to get the sealant soft. Most oils vaporize around 400 to 450, so heat the aluminum up until oil dropped on it smokes. If you don't get it hotter than that, you should not harm the aluminum.
CZ