[KeatonR]

So I have an '04 Lemond Poprad that came with a Bontrager crankset that has "Isis drive" printed on the side of it. I'm considering another crankset that says it's "Isis drive," so I'm assuming it's compatable? I'm confused mainly because a friend of mine says Isis is usually for Campy components, and I'm running Shimano. Yet the ad for the crankset says "Campy or Shimano." Can someone clarify for me?

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[xccx]

ISIS is referring to the bottom bracket. If you get another crankset that is also ISIS, just make sure that the bottom bracket size is the right size for your frame and you will be ok.

[cyclintom]

Campy and ISIS ARE NOT COMPATIBLE.

Campy bottom brackets are tapered squares as they've been for the last 50 years.

ISIS is an international standards group that merely documents standards. ISIS bottom brackets have a star-shaped pattern.

Campy's traditional design maximizes the bearing sizes that fit inside a bottom bracket.

ISIS tries to optimize the connection between the crank and the spindle at the cost of bearing size and surface area.

My take is that Campy's ideas are good and ISIS is stupid.

There's a third BB design which is Shimano's splined pipe bottom bracket. These seem to have all of the weaknesses of both of the other designs and additionally the are now apparently coming in different spline patterns and if you put a crank of one spline pattern on a bb of the other you destroy it.

Two piece BB-less cranks are also showing up and are a stupid idea in my estimation since wear on the section going through the cartridge bearings necessitate replacing the entire right side crank and of course they probably only sell the entire assembly.

So my analysis is that Campy is a better route.

[KeatonR]

Great, thanks for the info. So it sounds like if my crankset says "isis" on it, then I must have an Isis bottom bracket ... Therefore I can get the new crankset and replace my current crankset pretty seamlessly. Sound about right?

[xccx]

Campy and ISIS ARE NOT COMPATIBLE.

Campy bottom brackets are tapered squares as they've been for the last 50 years.

ISIS is an international standards group that merely documents standards. ISIS bottom brackets have a star-shaped pattern.

Campy's traditional design maximizes the bearing sizes that fit inside a bottom bracket.

ISIS tries to optimize the connection between the crank and the spindle at the cost of bearing size and surface area.

My take is that Campy's ideas are good and ISIS is stupid.

There's a third BB design which is Shimano's splined pipe bottom bracket. These seem to have all of the weaknesses of both of the other designs and additionally the are now apparently coming in different spline patterns and if you put a crank of one spline pattern on a bb of the other you destroy it.

Two piece BB-less cranks are also showing up and are a stupid idea in my estimation since wear on the section going through the cartridge bearings necessitate replacing the entire right side crank and of course they probably only sell the entire assembly.

So my analysis is that Campy is a better route.

I agree that ISIS is stupid, mainly because in my experience the BB's wear out WAY too quickly. But the OP said that he's already using ISIS/Shimano, so isn't switching to Campy a little drastic? I suppose instead of getting an ISIS crankset he could get a Campy crankset....

[xccx]

Great, thanks for the info. So it sounds like if my crankset says "isis" on it, then I must have an Isis bottom bracket ... Therefore I can get the new crankset and replace my current crankset pretty seamlessly. Sound about right?

if your cranks say ISIS...then you definetly have an ISIS BB. If you get a new ISIS crankset it should work seamlessly providing that you also get the correct BB (assuming you are replacing that as well).

[KeatonR]

Great, thanks everyone!