what does it mean if your uni is splined?

i hear its a good thing, but i don’t understand it.

Splined means that the cranks are attached to the hub using a splined interface. This means that rather than hooking them on to a square thingy, they hook them onto a thing with a bunch of slots. This means more surface area and less pressure, so the result is that you can do big drops and stuff and your cranks and hub wont get all screwed up. If you want to get into trials or street, you will need a splined hub and crankset sooner or later. A normal “cotterless” or square taper which you probably have now will break after too many drops.

A useful thread can be found here.

Wots the difrence between normal and isis?

Regular splines are just the companies design in the hub. Like how profiles have 48 splines, the older KH had 36, the older ones had 10.

But with ISIS, International Splined Interface Standard, that what it means. The hub and cranks are splined in a pattern that all other ISIS cranks use.

Before, a lot of uni companies would make their own brand of hub and cranks, with their own special way to spline them, but now, a lot of things are switching to ISIS, which will produce cranks just as, if not stronger than the older models, have a cheaper price on them, and be compatible with all other ISIS products.

ISIS has no pinch bolt. Splined does.

Um…no. ISIS are splined and only some splined cranks have a pinch bolt. The KH/onzas are not ISIS, they are splined and they don’t have a pinchbolt. Same with profiles.

As do profiles.

if the only difference between splined and cotterless is the fact that cotterless has squares and splined has… splines then why are splined hubs and cranks so expensive?

Because they are much, much stronger.

that was kind of established but can they make the splined hubs and cranks for the same price or is it more expensive to make.

It’s stronger, therefore it will last longer, therefore they can charge more for it.

Splined hubs and cranks are more expensive to make. There is more machining involved. But as volume goes up the price should come down.

You aren’t going to find any $12 or $20 solid steel splined cranks because that would be pointless. Why build a strong hub and then put a cheap crank on that will bend?

What cheaper to make, a square or a freaky star shaped thing with up to 48 points and grooves?

Also, most splined cranks are very carefully engineered and use strong light materials, while your average $10 cotterless crank is made of cheap steel.

Notice how these forged aluminium cotterless cranks are also selling for $100.

bear in mind cotterless is actually splined, it’s got 4 splines.

And steel is an alloy too. But not in bicycle-speak. In bicycle-speak steel is steel and alloy is anything made with aluminum.

Let’s not confuse things by exposing the inconsistencies of bicycle-speak.

In bicycle-speak a splined crank is any of the alternatives to the square taper crank interface and the obsolete cottered crank interface.

Splines are generally considered to be ridges on a shaft with matching indentations on the mating part (crank).