How to change Nimbus Venture crank arms?

I have a 36er and have 152mm crank arms. I would like to change to 125mm crank arms. I tried to screw the crank arms out with an allen wrench tool but the biggest wrench doesn’t seem to work. Do you need to buy a special tool to get the arms out?

After removing the allen bolt, you’ll need a crank removal tool. Like this:

Make sure the threads are all the way in before you start pulling the crank off or else you’ll destroy the threads and have real problems getting it out.

Is the crank extraction tool for Isis different than the crank removal tool for square bottom brackets?


It depends, this one can remove them both:

Have fun,

Yes it is. You require a larger push button in order remove Isis cranks without damaging them.

Some tools have interchangable buttons.

Is there a difference between Nimbus Venture 2 crank arms and the regular Nimbus Venture ones? My 36er seems to have regular Nimbus Venture 150mm arms and my 20 inch unicycle has Nimbus Venture 2 125mm arms. Would these be interchangeable? And if so, what tool would work?

Both Ventures will fit your hub as long as they are both ISIS. The Venture II’s are supposedly stronger, and I think they’re a tad heavier.

The Isis bolt hole in the cranks is bigger, so older, narrow, crank removers will want to push into the hole. But a US dime will fit nicely into the Isis crank bolt recess, and prevent that. You’ll probably dent your dime, though…

… which is why I have a couple of dome-shaped dimes in my bike tool box.

Or use a eurocent, or any other alike coins that would fit and cover the hole.

I seem to be stuck here. Whenever I try, it seems impossible to get it out. Any help is appreciated.

I was having a problem with this too (the crank bolt was on so tight it broke my cheapo hex wrench). But then I picked up a Park Tool Crank Wrench from a bike shop, and the extra leverage and strength of the tool allowed me to get the bolts out fairly easily.

This is the tool I used. It cost me about $12 at the bike shop.