Singlespeed & Fixed Gear - Interesting feeling on left crank

So heres the deal:

I recently replaced my cranks with ones I found from the co-op because mine were no good. Now when I pedal forwards and start to backpedal, my left crank has a weird slack in it. I mean I know this would be normal, but my chain tension is not very slack and it only happens on the left side. Also when I just move the crank backwards by hand, I don't feel this slack.

It has never happened before on any bike I've ridden.

So... crank arm is tweaked? Left pedal spindle got f'ed up? Hm??

edit: crank arms are both tight tight tight and such.

Thanks. :)

how much slack?

Breaking news: you're wrong. Extra slack could only come from the arm being loose on the spindle.
So either you're imagining the slack or the arm is loose (more than likely the taper is effed up) and you're not seeing it. You're obviously putting in more power w/foot than hand so it cd easily happen.
If the latter's the case, it'll become painfully obvious pretty soon tho.

my left crank fell off yesterday during sprints. wasn't tight enough. ooooooops.

Breaking news: you're wrong. Extra slack could only come from the arm being loose on the spindle.
So either you're imagining the slack or the arm is loose (more than likely the taper is effed up) and you're not seeing it. You're obviously putting in more power w/foot than hand so it cd easily happen.
If the latter's the case, it'll become painfully obvious pretty soon tho.


I have no clue what you're trying to argue with the extra slack bit.

Anyhow, I'm thinking the taper on the crank is messed up. I'll probably go pick up a different set tonight.

Extra slack as in there's more play in your left crankarm than the rest of your drivetrain. Sort of the whole point of your thread.
Jeez.

At some point, the crank was used while not tightened down. The BB spindle would have then played absolute havoc with it rendering it now completely useless. Sorry.

This is all true, the same thing happened to me way back when, I just kept riding it though, the bolt was loose and it destroyed my crank arm

LoFarkas, you're just not understanding the "play" I'm talking about. For example:

Flip the bike upside down. Hold the drive side crank tight and move the left one side to side. There is the normal chain play and then the crank wiggles/plays/shifts/moves on the spindle. BRANDUNE and Ingenous understand what I mean.

I found a matching size and style arm over at Firehouse Bikes today. I mounted the old crank on the drive side, the new one on the non-drive (to test weather it was the crank or BB spindle) and the new one seems dandy... I hope.

Good luck duder, problems like that are the suck

Good luck duder, problems like that are the suck

Thanks man. It isn't a huge problem because I got the cranks from free... you have to expect the occasional turd from a co-op. Luckily the new arm was $6 and looks even better than the other one did.

Going through the same thing right now, just toughing it out til my new cranks get in, tightening the bolt after every ride cause it won't stay. Can't wait to see what the taper on this thing looks like when it gets pulled.