What does ISIS mean?

I am new to this forum. I can’t find this anywhere. What is ISIS?

International Splined Interface Standard

There’s a little thing called Google that helps.

Thanks Greg,

Before posting I tried Google and Wikapedia but did not see anything that related to bikes or unicycles… When I added unicycle all I got was all the usual links found here. After looking through the first 20 pages of Google I still had not found anything related to the subject. Some samples found below:

Integrated Student Information System
Institute for Software Integrated Systems
ISIS Women’s Outdoor Clothing
Integrated Software for Imagers and Spectrometers
Interactive Spectral Interpretation System
International Society on Infant Studies

Once you gave me the correct phrase: International Splined Interface Standard

I could “Google” it and found the answer I was looking for Here

Thanks again for the suggestion

Yeah that site is useless. :sunglasses:

. . . really? . . . 20 pages huh?. . . interesting. ; )

ctrl + f “Isis” on that page will take you straight to it.

If you are feeling geeky… here is the full spec.


Pretty Geeky…

Thank you for the only pertinent and non-snippy response.

Thank you

Splined cranks are stronger than the old bike type square cranks

There was several different types. Around 2007 uni makers settled on the ISIS as a splined hub standard. The old square hubs are still around, and work well in street unis.

In splined hubs, the ISIS has taken over as the current standard. I have an 05 KH 24 with a different spline. Not a real problem, a tough kit, and I am happy with the crank length. But if I wanted to buy new cranks, I would have a smaller selection and pay 50% more, than for an ISIS uni.

www.isisdrive.com (whooops, beaten to it)

Anyway, incase you’re wondering… in a nutshell it’s a splined interface standard for cranks borrowed from the bike world. It is good, and simple. Pretty much retard-proof which is very important. :wink:

You’d have to be a bit of a tool to ruin an ISIS spline. On the other hand, Profile cranks’ 48 splines make for a stiffer interface but less retard-proof so that was one of the reasons why it wasn’t ideal as a splined standard in unis.

oh, you sound like you’ve never razzed anybody for not spending a few moments to really search for something :stuck_out_tongue:

Just don’t like the clutter of a short thread is all. Call it the OCD in me.

isis is just a way that a crank or hub is made. isis cranks will not fit on non isis hubs.

So you’re suggesting BMX riders are on average more intelligent (or just less sausage-fingered) than unicyclists? :stuck_out_tongue:

ISIS was a bit pants on bikes because of the restriction of the standard-sized bottom bracket shell. The larger axle diameter means using smaller bearings to fit inside the shell *, so leading to much shorter bearing life. Square-taper BBs are much more durable. On the other hand, it seems really well suited to unicycles, with the added bonus that the crank-stop spacer holds the bearing still.

  • Which is why a lot of bike BBs now have the bearing cups outboard of the shell, so they can run big diameter hollow spindles without having to worry about fitting the bearings within the size of the shell. May not be a problem on BMXs I suppose - do they still use the old “big” BB shell left over from the single-piece crankset days?


Oh mighty Isis!


Thank you all for the great information including you mbalmer.