Fixing someone else's bike that they got second hand, need to replace the BB, and thus remove the crank.
How this nut was screwed in, I cannot imagine. Also there is some broken plastic dust cap stuck in the threads…
Unfortunately I think this $30 pos is going to the scrap yard.
by pipette_monkey_4hire
14 Comments
[deleted]
It looks like someone used a nut from a wheel installed backwards for this. Those ridges are what bite into a fork or dropout of a frame.
Use another serrated nut and hope there is enough traction.
Plan B: weld a nut to it and use a wrench.
You could try to use a punch and a hammer on those indentations
It is threaded on backwards? How the shit does this happen?
Show us the other side please!
take a chisel or punch and tap the serrations in the loosening direction.
You have to ask: Is this bike worth fixing. It really looks neglected judging by the amount of rust and it must be old as it looks like a triple on the front. Those have not been that popular for years.
If the bottom bracket is bad and you’re replacing everything.
The only thing that can fix this is an angle grider with a cut-off wheel
Most other methods will cost more money and more effort
Lots of good suggestions. To confirm what I would try. 1. Cut a slot in it. 2 penetrating oil. 3. Leverage.
You could try a torx bit something big like a T30 to T40 that fits just enough to grab onto the metal.
While I was figuring it out, I’d tip the bike on its side and soak the area in penetrating oil regardless of next steps.
I’m hoping that this is a second nut on the couple threads exposed with the properly installed nut hidden beneath, and that the threads aren’t too buggered up for a crank puller. Otherwise I’d assume that the crank isn’t salvageable and go from there.
I think next, I’d try to drill holes in the nut the right size for a pin spanner If I couldn’t find my pin spanner or that didn’t work, I’d drill the holes deeper and pound some screws into the holes to pry. If that didn’t work, punch and chisel in the holes, or dremel slots to fit a fairly beefy big washer, turn the washer with an adjustable wrench.
A chisel and hammer to tap the nut out.
The nut is on backwards.
Then figure out the extractor threads.
An angle grinder can cut away the crank so the. Bb can be accessed and removed.
Since you got the nut off the other side then remove the bearing cap on that side and then see if you can get a tool in behind the chainrings and undo the bearing cap on that side of the bb and extract the whole lot. This is probably how they got that dodgy system installed in the first place
Isn’t that a backwards flanged nut? What does the other crank side look like???