By Steven Doetschman — fitness equipment technician and owner, Krislynn.comBefore ordering a replacement crank for a Schwinn Airdyne or Schwinn indoor cycle, you need to know which type you have. Steven Doetschman shows the two types side by side: ISIS cranks (post-2004 Schwinn bikes) have a star-shaped splined interior and are secured with an Allen bolt, while square taper cranks (pre-2004 models) have a square hole that presses onto a tapered spindle and use a hex nut. Identifying the correct type before purchasing prevents ordering the wrong part.
Full transcript
hi my name is steve and tonight i’m going to be showing you the difference between an isis crank and a square taper crank on schwinn indoor cycles there are two different types of cranks one is pre 2004 and that is a square taper crank and the inside of the crank looks like this and if it’s on your bike it’ll have a nut on it that looks like that and it’s a hex nut bikes after 2004 are called isis and they have a star-shaped interior to the crank arm and inside the nut that holds them onto the bike is an allen bolt and it looks like that if you have this kind it’s an isis and if it looks like this it’s a square taper the second part to the isis and square taper crank is called a bottom bracket and the bottom bracket goes through the bike frame and attaches the right side of the crank to the left side of the crank with your square taper bottom bracket fits directly into the square hole on the crank and this is for schwinn bikes dating 2004 and prior this is your isis crank and your isis bottom bracket and they fit together like this and these are for schwinn indoor cycle bikes after 2004.
