Rust coming out of crank arm, creaking noise when peddling

[newblah]

A few weeks ago my crank arm fell off while riding to work on a rainy day (http://i.imgur.com/mCZa26G.jpg" onclick="window.open(this.href);return false;) - the fixing bolt was missing and I got it replaced and everything was fine.

This week I've had a bit of a creaking noise come from my crank when peddling hard, when I got close to work this morning the creaking noise was quite a bit louder, when I stopped at work I noticed what looks like rust running down the crank arm.
http://i.imgur.com/q6rf7Ev.jpg" onclick="window.open(this.href);return false;
http://i.imgur.com/y3WJamu.jpg" onclick="window.open(this.href);return false;
http://i.imgur.com/vejVQvU.jpg" onclick="window.open(this.href);return false;

Anyone know what the likely damage here will be and what would likely need to be replaced?

Thanks

[jules21]

your bike is hemorrhaging. you need to get it to a hospital quick.

or you've spun a BB bearing. replace bearing. you will need tools if you don't go to LBS.

[bychosis]

And if the crank feels loose (assuming square taper), get it tightened ASAP. Additional riding on a loose crank may damage the crank and make it difficult to tighten properly.

Edit: My bad, should have looked at the pics. Only applicable to square taper cranks.

[duncan16v]

To tighten that style of crank, you're supposed to tighten the star shaped screw in the end of the crank arm to finger tight with the special tool, then tighten the Allen bolts to 12Nm - 14Nm. The bearings are meant to be tightened to 35Nm - 50Nm.

http://bike.shimano.com/media/techdocs/ ... 746319.pdf" onclick="window.open(this.href);return false;

[jules21]

tightening it won't fix the spun bearing. that rust is coming from oxidised steel. only steel near there is BB bearings.

[duncan16v]

The source of the rusty coloured water appears to be the bolt, but that's an awfully lot of rusty coloured water... http://i.imgur.com/vejVQvU.jpg" onclick="window.open(this.href);return false;

newblah - are you sure the rusty water isn't just mud?

[Nate]

id say frame full of water...

remove BB completely & drain/clean

[jules21]

The source of the rusty coloured water appears to be the bolt, but that's an awfully lot of rusty coloured water... http://i.imgur.com/vejVQvU.jpg" onclick="window.open(this.href);return false;

pretty sure the bolt is aluminium. never seen a rusty crank bolt. the bearings will rust if exposed to moisture, i.e. when they fail

[duncan16v]

The source of the rusty coloured water appears to be the bolt, but that's an awfully lot of rusty coloured water... http://i.imgur.com/vejVQvU.jpg" onclick="window.open(this.href);return false;

pretty sure the bolt is aluminium. never seen a rusty crank bolt. the bearings will rust if exposed to moisture, i.e. when they fail

That's why I'm wondering if that's just mud. The bearings in those sealed external cups are behind O-rings/seal arrangement (or, at least, they are on the Deore crankset I installed on my son's bike recently), so I'd expect the staining to be inside the frame rather than running down the crank arm - unless the the seals were lost when the arm fell off...

[jules21]

closer look reveals it may be mud embedded in the crank bolt recess! but that doesn't explain the grinding noise.

[ohexploitable]

the fact that the crank arm fell off in the first place indicates spline damage (i think)

[Dragster1]

Surely the OP would be smart enough to know if he has ridden through that colour mud or not. If the crank arm has been loose good chance that the seal may have reduced its effectiveness to seal and allowed water to enter the bb

[newblah]

Hi all.

This was definitely not mud, the fact that it was only on that specific part of the bike accompanied by the creaking that started getting quite bad made me pretty sure of it.

What I didn't report back on is that I tried riding the bike to the train station after work, all of a sudden the pedals were completely stuck and unable to move. Took it to my local LBS (Success bike force, WA) and they replaced the bottom bracket for me, the bottom bracket's seal containing the bearings had completely broken open. It was quite a mess.

Thankyou to all for providing some assitance! Its always good going into the LBS with some sort of idea as to what went wrong and what to brace yourself for

[newblah]

Also, Friday was the first time I've ever ridden through thick fog in my life, its amazing how the water seems to 'stick' rather than just rolling off whatever surface. I was unable to wear glasses while riding and got to work soaked!

[ohexploitable]

i was trying to peddle meth to some primary school kids but was chased away by the cops

[rustychisel]

id say frame full of water...

remove BB completely & drain/clean

This, completely. If the bearings are toast >50% probability you'll need to replace them.