Lowrider One Piece Crank 3 1/2" Chrome. for Bicycles, Bikes Bikes, BMX, trikes

As mentioned earlier, many kits come with wider one-piece cranks. That way you can reuse the bottom bracket. You can also buy short one-piece cranks on Amazon. This is helpful if you have a pull start. I have used these on two builds. You can also get pedal extenders for the short cranks. https://www.amazon.com/dp/B00GBF8NPW