This is how much chain slack is too much chain slack
 

With a wildly unround chainring, bent stays and damn near no dropout to tension with (semi horizontal), I ran an unideal chain tension just to get a bike on the road for a winter tank.

Now with a couple of months of salt, filth, lack of maintenance besides throwing more gunk on, and a heavy rider who likes doing the trick where you kick off and then stand one footed on the bike for a revolution or two on the chain, there's enough stretch such that I've thrown the chain three times in two days.

Today was potentially catastrophic: just going along, just gone through a green, no traffic, and hitting a bump the chain was thrown from the chainring, wrapped around the cog rotafix style, and caused me to have my first skid with low pressure knobby tires in a small gear at like 5mph on broken pavement. Unintentionally!

But all was well, there was a freshly littered snack wrapper on the ground to get the chain back out without too much gunking of gloves, and I'm alive to tell the tale of how much is too much slack.

This much:

http://i26.photobucket.com/albums/c1...6/DSCF0368.jpg

I'm not even sure the chain tension is the culprit here, I think that my bent and tweaked fender was actually creeping sideways enough that the broken frame mount just under the zip tie touched the chain and derailed it. But if a touch can derail it, it's too slack.

What happened to that chainring?? Is it supposed to be that eccentric?

that is about what I ride...

I hereby give up the Captain Slackchain crown to the esteemed ieatrats.

with a chain that slack, you might was well ride with a blindfold on too (intended for juvi-kyle)

ghetto... nobody smilin

who said I didnt...

that looked more like a ball-gag to me than a blindfold...

It's biopace.

I was going to have a rant in there about how it seems the opinions on chain tension here border on fanatical, but I guess it's too late.

my mtb sags that much, but never went off-track even when i went bouncy-bouncy on the rocks. i wouldnt tolerate that much on a fix, though, cuz the freeplay on the pedals would drive me cojones

true...true

wow. that looks like a hammock for little chain-throwing Gremlins of Slack to chill in.

Like a pirate with a steering wheel up his ass?

To lose is when you roll a bike into the back seat of a car and the chain falls off because gravity derails it.

That probably counts as to lose. :D

there should be zero visible droop in the chain, about 1/2 inch of deflection when you push on it max.

Arrrr! It's drivin' me nuts!

Man, that is some serious bike abuse. Clean that bike! Get a new chain, already.

Yeah thats way too much slack! That would drive me insane. I know its a mountin bike but clean that thing a bit would ya.

Biopace!

Agreed. He's an accident waiting to happen with a bike in that condition.

Welcome to the club. People here put the blame on my cog. But it got me a new rear end

Ay! It's drivin' me nuts!

I don't know why that made me laugh as hard as it did.

advice which i ignored last night, instead opting to ride with droop: "i'm only going a few blocks, i'll tighten it once i get there." two blocks from my house i threw my chain going over a tiny bump and fredflintstoned to a stop. classy.

It is especially important to keep little or no chain slack when your shoes are your only brakes.