Okay. Now that we have the crank arm off, we can put the new crank arm on. Basically what you want to make sure is that. So again, this is a square taper bottom bracket. It's probably one of the most common. There's other tapers, so meaning what this piece is right here. And there's also different cranks. Especially modern cranks they are installed and taken
off differently, so you want to make sure that if you are installing or
taking off a crank that if you're doing it this way, that it's a square
So make sure you put the arm back on correctly, so it's opposite of
the other arm. You don't want to do something like this, where you will
not be able to pedal very well. So just press it back on, making sure that
this is all clean. Make sure that the taper's all clean before you put it
back on and that the natural crank arm is nice and clean. So put it back
on. Take your crank arm bolt, which this is the eight millimeter crank arm bolt,
making sure you put some grease on it. We have some part grease. You
can use any type of bicycle grease would work well. Partfil, Finish
Line, all those. Take your eight millimeter hex or allen and screw it on, making
sure that you're not cross threading the bolt.
So when it's nice and snug and you get the long arm part of the tool and start to wrench it down. And basically, what this is doing is this is pressing this arm onto this taper. So since its tapered, it's kind of pushing up onto it.
And then once you get to the point where it's getting really tough to turn the bolt or the nut, you want to make sure that you give it a nice snug, tight jolt. It's about 50 pounds of pressure to make sure that it's on there really well and that
it's not going to come off.
That's how to install a crank arm for square taper bottom bracket.