M620 Went Down After Brake Lockup

[MonsterHPD]

I haven't read your previous post, but I once (approx. 1988 or so)had a similiar thing happen to me on my Yamaha XS650/860, even if I managed to stay upright (barely). On that bike I had a Brembo master cylinder for the front brake with what seemed like an adjustment screw for the lever position which I used to position the lever at a comfortable distance from the bar.
Unfortunately, this also moved the piston in the master cylinder enough to close the connection between cylinder and fluid reservoir, creating a closed brake fluid loop at the calipers.
Having ridden for a while and braked anough for the brakes to heat the fluid, the fluid expanded and gradually applied more brake, creating more heat.... you get the picture. As I approached a crossroads, the front wheel suddenly locked up at maybe 20 km/h, quite surprising to say the least.

If something similiar hppened to you, the front wheel should have been locked up when you picke the bike up. Was it, or did it rotate freely?           

[Kegan]

I was in the left side of the left lane. I think road conditions were fine, of course speaking from a place of inexperience. The brakes had last been done by a Ducati dealership in the bay area, where I bought it. I didn't see any reason to bleed the brakes as I was putting the bike back together, as the calipers fit over the rotors without trouble, and the brakes performed during the seating of the axle as well as during the test rides. I'm thinking about this logically, and the weakest mechanical link on the bike remaining after my first accident is the fork assembl(ies). Like I said, new ones come tomorrow. I suppose we'll see where things go after that. Bent forks can cause unpredictable handling, right?

Edit: I'm sorry, I didn't see the post above. The wheel rotated freely when I picked it up, although that was a good hypothesis. I did (after this) adjust that screw though... Any way to prevent what happened to you? I'm 100% inexperienced as you can tell, I just don't want to get killed by the learning curve.

[Kegan]

Update: Play in chain tension, measured as according to the idiot-proof sticker on the swingarm, was a whopping 40mm as opposed to 20-25mm spec. Perhaps this had something to do with things... 

[bikepilot]

Very unlikely provided the chain is still on the sprockets. Even if it did somehow get bunched up, lock the wheel, then free itself it would just cause the rear tire to slide - that's pretty controllable and wouldn't violently and suddenly pitch you off.

The MSF class is a great way to get some initial training, but don't take it as a stamp that you are now competent to ride around on the roads safely - it just means you went around some cones in a parking light without scaring the crap out of the instructor    I advocate becoming an accomplished rider in a closed-course environment before playing around on the rather-unforgiving, guardrail lined, cage infested streets. 

If I had to guess I'd say its fairly unlikely that a mechanical fault contributed to the accident.

FYI it isn't too uncommon for forks to get twisted in triple clamps without being bent - that the front end wasn't straight when you were going straight doesn't mean anything is bent - its possible something is bent, just not certain.  If you've already bought new forks I guess you might as well use them, but if they are used forks or if you haven't laid out the $$$ yet, just check to see whether yours are bent, if not loosen all pinch bolts (including at the axle) then re-torque properly.

[Bones]

my honest opinion is you locked up the rear and panicked.

Happens to the best of us. You learn and move forward.

[900ssfe]

I'm 100% inexperienced as you can tell, I just don't want to get killed by the learning curve.

You're not 100% inexperienced, my Nephew.  You're actually gaining it in leaps and bounds.  One cannot learn without making mistakes, I'm confident that you will be more careful due to your recent interactions with asphalt than you were prior.

Make the bike mechanically safe and sound to give yourself piece of mind, throw on your riding gear, and go ride.  You have 9 lives, just don't use them up so fast.

J