Downhill rear hub standards?

[monkeyseemonkeydo]

A friend of mine is looking to produce a prototype hub for DH which would allow the rider to change gear while freewheeling. He's pretty much sorted the mechanism but to make the prototype needs to determine what sort of axle system needs to be used to suit most DH rigs so a few people could give it a go. I'm guessing this is something along the lines of 150mm x 12mm (?) through but are any of you more familiar with the current 'standards'?

[haydon_peter]

That is the more widely used 'Standard' in DH although some playful short travel 'freeride' frames (Specialized Status and Scott Voltage FR for example) use 135mm axles, I think they are both 135mm x 10mm

[Matthew62]

12mm axle with a 150mm wide hub. A 9/10 speed cassette body seems to be the standard.

I'd consider SRAM XX1 and it's growing popularity but it's certainly still a small thing and not sure how it'll work in DH applications.

[dezmtber]

150x12 fits most and the other size is 135 x 12

Which the status uses.

And just throw in a spanner hope 135 x 12 have optional end cap adaptors to fit the newer 142x12 standard that is the same as 135 only the frame has slots which the longer hub drops into to make lineing up the wheel easier.

If you want it to fit dh bikes then 150 but if you want it to fit enduro/ freeride bikes then a 135 shell with optional end caps.

The problem is the 150 hub shells have to be wider than the 135/142

[monkeyseemonkeydo]

All good info, cheers guys. I think to start with I'll advise him to use a 135mm hub so it can be tested on 'normal' bikes before trying it on a proper DH rig.

[craigjames]

There's also the newer 157x12mm. I'd discount Sram 11 sped stuff for DH, there is just no need for the huge range and the massive top end gears.

[Krisboats]

157x12 sounds a much better system so i reckon that'll take off pretty soon.