Friday, 13 June 2014

Aluminium: a love/hate relationship

I'm totally aware that I've changed like, everything, despite keeping all the old posts and such. There's more to that, all for another post.

So as I'm doing a drivetrain rebuild on my road bike, there's bound to be lots of twisting. Some involve hex bolts, others involve messing with the cassette cluster in the rear wheel, and even replacing and dishing eight spokes in that wheel.

So far, so good. The wheel is dished satisfactorily with regards to my limited amount of tools compared to a bike shop, new cassette cluster is installed and rim tape ready to roll before I reinstall tube and tyre. The old chain is disconnected and my cranks actually somewhat resemble a spider now that both chainrings are unscrewed. And the old rear derailleur, hanger and shift cables are also headed to the dustbin as well, especially considering that the derailleur and hanger are unusably bent.

But hold up. Whilst removing the rear shift cable and housing, taking the adjusting barrel on the down tube with it, it didn't take much unscrewing effort for the damn thing to crack and separate, leaving my hand with the adjuster head and part of the screw, with the other half still screwed in but running headless.

Before you start assuming variables that got me into this predicament, I do confess the following:
If you're reading this in a non-graphical terminal, or just simply tl;dr, basically, deferred maintenance in the past caused this big time.

But while deferred maintenance was the major player, I do need no highlight the rather poor durability of aluminium fasteners. When dealing with the screw types, a wrong push, pull, shove, etc can have the heads stripped within seconds. The proof is in the strength and yield numbers compared to, say, steel.

But aluminium is what my frame is made of! It's relatively cheap (due to easier manufacturing) and can be made stiff and light in certain ways. Dings in the front three structural tubes are not a problem structurally. But it's a bad idea to use aluminium fasteners! Even with periodic re-greasing and whatnot, something just doesn't sound right.

In the meantime, while I'm back to riding my steel frame fixed gear cyclocross bike around, screw and bolt extractors are calling my name. More to come.

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