... and thats what Im currently having :)
My bike was running much better after the work I did in BA, but it felt "funny" at manoeuvring speeds in the streets. I didnt notice too much because Ive been doing lots and lots of long highway miles and almost no slow stuff (or mostly in gravel parking lots etc where you cant "feel" the bike the same as on pavement).
Anyway, it seemed to be getting worse and the symptom was a very surgey and uneven low speed "loiter". It felt like a slack or very old chain... But I just replaced that.
So, I decided to take a look at it at one of my fuelling up stops... And the rear sprocket and chain were indeed fine, so I broke out the tools and took off the front sprocket cover (which I had not done in the big fix up in BA)...
... And yes indeed!.. There is a serious problem here!
Im in definit need of some urgent "Dental Work"!
The teeth on the front sprocket are all almost worn down to nubs!
They were a bit worn when I checked them last in Chalten... but that was 15,000Km ago I guess.
That did happen really quickly though or Id have been checking more often... But that makes sense too I guess...
Modern hardened metals (like chains and sprockets) are not hardened all the way through (heat treatment process). They just "case harden" them (its faster and cheaper of course) so that only the surface layer is hardened and once you wear through that hard layer, the softer metal below wears very quickly.
But while thats all very interesting, it doesnt get me out of my current sticky situation... Which is:
Im in the "Lower East Side" of Bolivia... Almost in the middle of absolutely nowhere!
Ive got a REALLY bad front sprocket and no chance of there being a spare anywhere nearby! (They dont import my model of bike here in Bolivia)...
Note: once the remaining nubs wear off (very very soon) then Ill have absolutely no means of connecting the engines power to the rear wheel... Not going anywhere! But other than that, no "damage" will be done to the bike.
What to do??
Well, I only have to make it to Quito in Ecuador where a friend (who is coming down for a vacation) can bring me the new part from Canada in a couple of weeks. But thats about 4000Km away... I wont get there like this!
So, worst comes to worst, then I can find a welding place and "weld" extra metal onto the back side (away from the nice smooth face where the chain rides when under load) of the little that is left of each tooth... Thats really ugly but it would work.
A different option would be to get a new sprocket from a different bike (that wont fit the drive spline on mine) and then get a machine shop to cut out the centres of both the old one and the new one and then weld the new teeth onto the old hub... "Franken-Sprocket" is born! Mwwaaa..haa...haa..haaaa!
That would work better but I gotta get the right "donor" sprocket to fit my chain size (its a 525).
But either way, for the moment I just gotta get to a place where I can attempt either one.
... Fortunately, its only 500Km or so to some sort of a city down here in the jungles of Bolivia...
I figure I can make it that far :)
... and so, I set out for it (albeit gently on the throttle) at once!
