A Micro Spline freehub body is required to run a Shimano 10-51 tooth cassette. White Industries' 12-spline titanium freehub design.

Hope has raised questions about what they see as an unfair distribution of Micro Spline licenses from Shimano in a Facebook post last week.Micro Spline is a new driver body standard that was introduced when Shimano first unveiled its XTR 12-speed drivetrain last year. Up until that point, Shimano had been using the same basic freehub system since the dawn of index shifting, but that did not allow for cassette cogs smaller than 11 teeth. The Micro Spline freehub design has 23 rectangular splines that allows for the use of a multi-part cassette with a 10 tooth cog, as opposed to SRAM's XD freehub design, where the cassette is threaded onto the driver body.When it first launched, Shimano said it would only be licensing the Micro Spline standard to DT Swiss, but since then several other brands have been granted licenses. And don't forget White Industries, who decided to create their own titanium freehub with 12 splines that just-so-happens to fit a Shimano 12-speed cassette...Hope had apparently had a fair few requests for a Micro Spline hub, and they even have the CNC programs ready to go, but without the license they can't actually sell them. In an effort to explain this to their customers, they wrote on Facebook on May 31, "We have been talking with Shimano ever since the new standard was announced. They stated that they would only offer it to OEM hub manufacturers and the hubs must be branded with the bike manufacturers name. They also said they would not release the licence to aftermarket hub manufacturers."Looking at the wheels and hubs listed around the XT and SLX launch it seems that they are stating different rules to each manufacturer which is disappointing for us and our loyal customers. We’ll continue to lobby Shimano for the licence and keep you informed of any developments."We reached out to Shimano and they said, "In addition to our own XTR M9100 hubs, Deore XT M8100 hubs and wheels, and SLX M7100 hubs with a Micro Spline freehub, brands including DT Swiss, Mavic, Newmen and Industry Nine are licensed to produce their own freehub bodies with a Micro Spline structure to fit the Micro Spline cassettes. This means that these brands can offer complete Shimano-compatible 12-speed wheels. Additional hub brands using the Micro Spline freehub body will be announced in the coming season."We also asked Shimano to clarify the conditions that must be met for a Micro Spline license to be granted, and why certain manufacturers such as Hope had not been granted a license, but they declined to offer any more comment to help demystify the situation.We'll update you on any more news as we get it.