Thursday, June 24, 2010

Assembling a Sportbike... from the center out

October 2009 (8 months ago)... we went to ride on a sportbike track-day to the coastal race track of San Antonio, About 90 minutes from Santiago at legal speeds.

When we arrived at the gas pump before entering the track my Buell S2 Thunderbolt had developed a rattling noise in the engine. My first impression was that the engine could have overheated (we got there in 70 minutes), or maybe an engine rubber mount was getting old.
When ridden a little faster than idle the noise went away and I could foolishly forget about it, as if nothing was wrong (but I knew better), but what the heck I'm on a race track in racing leathers with my sportbike already, let's hope it lasts till the end of the day. It almost did.

By 5:30 PM I was going at full throttle on the long straight of the back of the track, ready to brake at the approaching right U turn, when the bike took the matter on it's hands and slowed first. I had to accelerate and downshift a couple of times to keep it going, the engine was going almost freely in 5th. In 3rd gear i got some grip and I almost managed to reach the straight in front of the pits, before stopping the poor rattling bike that refused to ride one more block.

I felt cool like those MotoGP race pilots who have to walk after surving a bad crash, except I hadn't even crashed. "something broke" I said to Vicente, our instructor for the day. Must be the clutch he said after i described the death. Easy piecy... clutches are not expensive... I got a few laps on a Bandit 600 that seemed electric compared to the Buell, and then I got to ride with the crew hauling bikes back to Santiago... perfect day.

Turns out it wasn't the clutch, but the crankshaft, whose teeth were grinded flat by the generator rotor who won the tooth grinding battle after getting loose from a nut, who in turn got rid of it's retaining pin... ok, lost? If you know nothing about engines, the crankshaft is like the heart of the engine, it is at the very center of the bike. It's what transforms the back and forth movements of the pistons produced by some very explosive and frequent air and gas cocktails... into the rotary motion that makes your wheels turn.

Loosing your engine crankshaft is like having a broken neck. On a giraffe.

So, it's been 8 months, almost enough time to create a human being, and after ordering parts from a US dealer, and Buell Motorcycle Co. going out of business (Courtesy of blind Harley Davidson Motor Co.), and chasing down mechanics and metal artists of all sorts... the crankshaft is almost ready. Assembling the Buell back seems a concrete possibility, so last week I had a revelation... "If not now... when am I going to have the chance to assemble a Harley engine back into a sportbike from scratch?"

I don't think you get the time and energy to re-build an engine in a completely disassembled bike very often, and with the lakehouse almost over this looks like a fun project where I can learn more about mechanics. I'll take the opportunity to paint myself it on the classic HD VR1000 orange and black halves as well. So last saturday I picked it up from the garage who was supposed to assemble it, and hauled an empty frame with wheels, four boxes of engine bits and a bunch of body parts in the pickup truck, all of which my son Pablo and me unloaded everything in our motorcycle garage the next day.

Just before it started raining... just before the delicate engine parts started rusting.

We carefully cleaned and bathed every single engine part in oil. We tried to guess what some of them were for, or where they could go... Then we stored everything in new plastic drawers just designed for oily Harley Evo engine parts all eagerly awaiting for a shiny crankshaft to arrive and wrap around it.
So in a couple of weeks I'll be start a bike building project, with a little help from Haynes or a similar mechanics handbook, a little help from my sons, and lots of time and a few dark beers as fuel...

Final note: It's quite amazing how compact how motorcycles are when assembled, take a look how far they can expand when you tear them apart.


Pamela Miranda said...

ok now, we only need you to do some baking to be back in full :)

MarceloM said...

Actually.. I've baked some pretty good bread in Rapel lately. But you mean writing about it, so I'll get to it soon...