Shimano's only patent on the freehub cassette system, isn't on the shape of the cut-out of the interior of the cogs, it's on how the freehub body, (the ratcheting carrier that the cogs slide on), is fastened to the hub shell. Shimano's uses a steel bolt built on a steel tube, that has a 14mm by 1mm thread pitch. The inner diameter of the bolt is 10.5mm which permits the 10mm diameter rear axle to pass through it. The Shimano steel bolt has a 10mm hex fitting in its interior, so that with the axle removed, a 10mm hex wrench turned counter-clockwise (anti-clockwise) will remove it.
The original weighs 13.5 grams. SRP makes an exact replacement of Ti 6Al-4V rod through a bit of complex machining that weighs just 7.5 grams. This will replace the bolt used in the LX, DX, XT, and XTR. It will also replace the bolt used in the RX100, 105SC, and Ultegra freehubs. It will not work in the Dura-Ace hubs because they are of a very early design, and we have said that we believe Shimano has these scheduled for re- engineering in the 1996 model year when this bolt may be compatible. Remember there are several aftermarket hub makers that also use Shimano freehub bodies freely with the Shimano bolt, read about the hub you have to see if this will be useful. $ Price in Catalog
SRP makes hollow Titanium axles as replacements for the steel ones that come commonly in production Shimano or Suntour hubs. The axle used in all Shimano & Suntour front hubs is hollow, with a 9mm outer diameter and a 5.3mm inner diameter with a 100mm length when measured from the outer edge of the lock nut to outer edge of lock nut, (over lock nut dimension). The rear axle used in most Road hubs is hollow, has a 130mm over lock nut dimension, with a 10mm outer diameter and a 5.3mm inner diameter. The axle used in new Mountain hubs at the moment has a 135mm over lock nut dimension, with a 10mm outer diameter and a 5.3 mm inner diameter. The SRP Ti version is an exact replacement for these, with threads cold rolled into the axle.
Ti hub axles is something they have pursued beyond the common, and they make Ti replacements for the Campagnolo hubs. The Campy front axle replaces the same one used in the Campy Chorus, Record and Record OR, having a 9mm by 1mm by 100mm O.L.D. The Campy Freehub rear version will replace the axle used in the Campy Chorus, Record, Record OR or the aluminum body Super Record.