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Barry2 05-24-22 01:52 PM

MTB / Road Micro Spline hubs different ?
Can a Mavic Cosmic SLR 45 (Road wheel) be converted to Micro Spline via a freehub change ?
For the Mavic ID360 hub, I can only find "MTB Micro Spline" freehubs.

And those Freehubs don't list compatibility with the Cosmic range of road wheels.
Maybe MTB & Road Micro Splines are different ?



Rolla 05-24-22 02:53 PM

I'm not super up-to-date on Shimano, but I'm not sure there is a road Micro Spline.

According to Shimano, it's "only compatible with Shimano produced SLX, XT, and XTR/Micro Spline specific cassettes," although I think this has since been expanded to Deore. According to Bike Radar 8/21, "Shimano is debuting a new 12-speed-only freehub design with its new groupsets and no, its not Micro Spline"

Barry2 05-24-22 02:57 PM

Shimano does list the Ultegra 12 speed cassettes as Hyperglide and Micro Spline compatible.

Still confuzzzzzed


Rolla 05-24-22 03:57 PM

Originally Posted by Barry2 (Post 22518503)

Again, I'm not really a Shimano guy so I might be wrong here, but on that site I only see that "Shimano ULTEGRA R8150 drivetrains ... retain compatibility with existing HYPERGLIDE FREEHUB bodies."

I know that Shimano has a new Dura Ace 12-speed freehub, but it's not clear if it's Micro Spline.

From Bike Rumor:

cpach 05-24-22 11:47 PM

Yeah, Shimano semi-annoyingly came out with another freehub spline pattern (like they did with the 10-speed-only hubs they briefly had). The cassette with fit on that or on a normal HG-11 driver. The motivation is to have better spline engagement so they can make it out of aluminum (like that one time, with the 10 speed...), but unlike microspline it still has a 11t minimum cog size.

*Scuba 05-25-22 12:15 AM

The new Shimano 12 speed road cassette and freehub body is HG+ L2 (hyperglide plus). The MTB freehub is microspline. The two are not compatible. New 12 speed Shimano road cassette can be installed on (backwards compatible) with Shimano 11 speed (36mm) hyperglide freehub bodies.

Currently Shimano has FIVE freehub standards right now.

Barry2 05-25-22 02:17 PM

Thanks for all the help... I've got my answer.

Micro Spline hub = MTB only (no compatibility with other cassette standards)
New Hyperglide hub (HG) = Road and will accept an original HG cassette (11 or 12 speed) or a New Hyperglide cassette, 11 or 12 speed. (no Micro Spline compatibility)

The longer Version
Micro Spline is for MTB only. It permits the use of a 10T smallest cog.
However there is no compatibility with other cassette standards.

The older standard, "Hyperglide" relies on 9 teeth on the hub (8 large, 1 small) to stop the cassette from spinning.
I'm now seeing this standard referred to as "HG11"
Problem was that the usually steel cassette would cut into these 9 hub teeth if the hub was alloy and not steel.

In order to fix this issue you need more teeth to spread the load on an alloy hub teeth.

Time for a new standard, I'm seeing it called HG12.

By cutting the 8 large HG11 teeth in half you get 17 teeth total and can spread the load, ideal for an alloy hub body.
Better yet, because they left the teeth at their previous HG11 spacing, regular HG11 cassettes fit, regardless of if they happen to be 11 or 12 speed.
HG11 cassettes just engage with the original 9 teeth of HG11.
But if you happen to have a HG12 cassette, it can make use of all 17 HG12 teeth.

I got there in the end.


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