Shimano has already patented an internal gearbox system. It's quite clever. Two cassettes with a chain connecting them & a derailer. It looks like intended for bottom bracket mount, not hub. It would force frame makers to design around their system. Quite Shimano.
I read about it some time ago & don't remember where. The author described the system from what he could figure out in the patent. A google search will probably locate it. dougP On Sunday, September 12, 2021 at 9:46:08 AM UTC-7 Patrick Moore wrote: > Grant spoke of *.... the SRAM-SHIMANO cogs race that, you should know, is > going to culminate in an internal drive train that will be the end of the > obvious mechanical bicycle in..ten years?* > > I like Grant's preference for simplicity, but I also think that there are > huge undeveloped possibilities in hub gear drivetrains that will re-connect > us with an ancient line of drivetrain development that started > commercially in the 1880s -- there were earlier experiments -- and that > Sturmey Archer continued with its dozens of models until the 1950s. > > Since then, development has been aimed at the utility market, except for > Rohloff, but I think there are great possiblities for better designed and > better made hub gears with more intelligent gear spreads and greater > reliability and lower drag. > > Note that IVT claims 97% efficiency for its CVT hub gear. > > Patrick Moore, who expects a Sturmey Archer TC in the mail on Tuesday (2 > speed fixed with direct high and 86.54% underdrive, 76" and 66"), and who > also has AMs (3 speed freewheel: 111.5% overdrive, direct, 86.54% > underdrive, 72-65-56) and a TF (2 speed fixed, direct and 75% underdrive, > 72", 54"). > > > > that more or less dead-ended in the 1960s, with some exceptions like > Rohloff and Nuvinci > > -- > > ----------------------------------------------------------------------- > Patrick Moore > Alburquerque, Nuevo Mexico, Etats Unis d'Amerique, Orbis Terrarum > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/c3d3b79d-5725-4877-815d-22f177ed5d74n%40googlegroups.com.
