DA 7710 NDS Crankarm Dust cover/extractor threads

dyrlac

In the process of moving my DA 7710 crankset to my new fixie, I managed to strip the heck out of the threads that the crank puller attaches to*. While I managed to avoid stripping so many threads that I eventually got the crank puller to engage, the dust cover, which screws into the same threads, refuses to cleanly screw in. It's not helped by the fact that it gets fitted using a peg/pin arm spanner, which doesn't afford the best of leverage. Anyone know how critical these dust covers are? DA 7710 is a old-school 3 piece crankset, using the octalink standard. Has anyone successfully used a thread chaser on a set of extractor threads?

* lesson learnt, using a penny because you can't be arsed to hunt for the correct diameter pusher isn't a very good idea when a penny isn't really the correct diameter either

paul_onabike

The "Dust Cover" is part of the self extracting crank mechanism, you don't need an extractor tool. When you undo the crank bolt with the allen key- you keep undoing it and it pulls the crank off.
The cover is not required to fit the crank to the bottom bracket, just tighten the allen bolt to the correct torque.

dyrlac

Paul Onabike wrote:

The "Dust Cover" is part of the self extracting crank mechanism, you don't need an extractor tool. When you undo the crank bolt with the allen key- you keep undoing it and it pulls the crank off.
The cover is not required to fit the crank to the bottom bracket, just tighten the allen bolt to the correct torque.

Yeah, worked out after a while that the cover was a self-extractor :oops: (only defence is that I've spent a lot more time with ordinary square tapers). Any danger in running without it? Don't think so. May attempt to chase the threads though.

keef66

As long as the crank bolt's done up properly there's no danger in running it without the self-extractor / dust cap. Just looks a bit naff, but functionally fine.