Is my crank set dead???

[Andy]

I know I should probably spend the lousy $40 it would cost to get a new crank set (a closeout set obviously), but I wonder if I really need to. Plus my wife was laid off, so we are a single income home right now.

My problem is, that my crank arm came loose a few times on the last ride. I used (blue) locktight, but may not have cleaned the threads properly before applying it.

I sprayed automotive brake cleaner in the BB (in the spindle where the bolt goes) and cleaned the bolt real well. I covered the bolt with locktight and cranked it down.

I'm gonna try it today, but was wondering if I'm trying too hard to save the unsalvagable.

What do you think???

[Old Proflexer]

that sounds more like a bottom bracket / crank bolt issue and not necessarily the cranks - if the bolt works loose, the cranks will as well.

the bolt holds the crank arm on by screwing into the spindle.  might try a new bolt with some fresh threads if the old one seems to go in too easily, try wrapping the threads with a little teflon tape, spraypaint or nailpolish and let dry the threads, rough up the threads of the bolt a bit with a file or such.

lotsa things to try before shelling out the big bucks.

OP

[keen]

  Are you torqueing it to spec.? 28-30 ft. lbs. After it is torqued down remove the bolt and make sure the crank arm is not bottoming on BB, if so the arm is toast.

[Carbon_Angus]

i cracked two shimano XT crank arms on my 857, if ther are no cracks down there (clean it and take a look)otherwise, i agree with the BB theory.

[Irby]

Andy, I once saved a crankset by shimming the bottom bracket taper surfaces with pieces of aluminum from a coke can. If your crank is on it's last legs and nothing else works, give it a try. Dan