Right! Would have been so upset if my bike got hurt.

 

That sucks. I couldn't imagine being able to keep the bike upright if that happened, but when you're in that situation, i'm sure "beast mode" instinct kicks in. This is one of my fears while riding. It's something we risk each time we get on the bike, even if we think things are mechanically sound and I may get relaxed on the bike, but NEVER lose focus. I always try to be aware of how I should react if something comes at me, a tire blows, car turns in front of me or something starts to shimmy at high speed. A few times, cars have started to merge right into me, as though they can't hear my loud a$$ pipe and I immediately reacted and moved over to the next lane to avoid a collision. This is how we should train ourselves when on the street. And what happened to you is one reason I always, always buy the best product I can find when it comes to drive train and tires. For me it's RK chains and sproks and Michelin for tires. And I have an excellent mechanic to do the things I don't do myself. I wonder if that chain had the quick clip on style link. I've heard of that same thing happening to people just a few miles in with a brand new chain. By the way, that chain looks REALLY dry. Did it break at the rivet part or a random link?

 

It was a clip masterlink and the clip broke so the link slipped out. I'd use rivet links but I don't have the tool to do it. Chain actually wasn't too dry but the pic makes it look that way.

 

For what it's worth, you don't need any special tool for using rivet master links, though it does make it a little easier.

All you need is a ball-peen hammer, and a heavy piece of steel to go behind the chain, like a large weight disc, or something of the like.
You can use vice grips, or some sort of clamp, to carefully and evenly compress the outer plate over the pins, to where it is fully seated, then, just position the chain to where you can put the steel piece behind the master link, and use a ball peen hammer (the rounded end) to strike the pins, mushrooming the ends of the pin out, so that they hold on to the plate... works like a champ!

I used this method many times, before I finally broke down and replaced my chain tool - if it's done properly, and it's not difficult at all, it will hold just fine - one of the last race chains I used this method for, gave me 7,000 miles of service, with most of that on the racetrack.

I would never recommend a clip-style master link...ever!

 

If you use a master link chain you must do the following. When installing the link, lube the pins before inserting them, put on the o-rings and the side plate. When installing the retaining clip, make absolutely sure that the open end will be facing to the rear of the bike when it is on the upper run to the counter shaft sprocket. If the open end is facing forward it can spread or catch under load and get peeled off. When you install the clip you cannot distort or bend it, as it will create a weak spot that can crack. Lastly, safety wire the clip. There is enough room to run a loop around the clip and twist the ends so that they face the same direction as the open end of the clip. Some guys used silicone seal, but I never trusted it to stick to an oiled chain. I've been doing it this way on many different bikes since 1978. Haven't lost a link yet. But I check it each and every time I ride to see if any wear or damage has occured to the wiring or the clip. I also run a 520 chain on my F2.

Rivet chains are used by most all of the manufacturers, so it must be safer, as they worry about liability issues more than we do. Whichever type you use must be installed, adjusted, oiled and constantly monitored or it can lead to really bad things.

 

I looked closely at your picture of the chain. I noticed that the one side of the chain shows a mark where the o-ring was, but the other side doesn't have it. Perhaps the o-ring didn't get installed or was pinched and fell out. Check out the pin on that side of the link and see if it fractured. The pin is too far in for me to see.