Saturday, March 2, 2013

One Crank arm on my Wagon

Generally, I find that once I have completed a series off tasks designed to correct a fault everything starts to go swimmingly. The issue with the chainset on the Ridgeback Adventure 520SX had left me a little stumped. What do I replace it with? Do I stick with the three at the front or move to a two ring configuration. Do I keep the old bottom bracket which although not showing signs of wear is many miles old and will need replacing sooner or later? If I replace do I stick with the sealed cartridge bottom bracket or adopt the Octalink version for which more chainsets are available for 9 speed set ups?

I spent a lot of time kicking these ideas about and thinking I will need to get the bottom bracket off just to check the BB size when.....I found myself on a gentle training ride with my foot attached to the pedal but the pedal no longer attached to the crank arm. The cheap light aluminum arm that had come with the bike back in those oh so dark 1990's had finally worn away against the better tensile strength of my pedals. OK fine so now I have to replace the lot. Might as well clean it all up and start again.

But although I got the non-drive crankarm off easily using the crank puller the same couln't be said for the drive side. Years of use and grime has finally caught up and bit me on the butt. I should have paid attention and taken these off and cleaned them. It takes a lot of leverage and a large amount of penetrating oil (not a light oil like WD40 but a lube containing graphite) and some patience to finall be able to extract the drive side. This can go in the scrap metal recycling there is nothing that can be re-used here.

Now for the bottom bracket and no surprise here again it proves troublesome to remove the drive side, and this is all the time remembering that drive side threads on a bicycle are all left handed. In otherwords the reverse of conventional "righty tighty lefty loosey". Lots of cleaning fluid and degreaser needed to be used along with doses on penetratiing oil until finally the grit and grime are removed and the seals are broken. For good measure I applied a few light taps to break any metal on metal bonding. No idea if this works, but it did seem like a good idea just in case.

So now all is stripped out and the bottom bracket is undergoing a full degrease and clean ready to accept a new bottom bracket. I know the size, 68mm as suspected, but the decision now needs to be made as to which one?

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