Cassette cogs in Shimano IGHs & spacers
Feel free to correct if needed.
Hubs: Nexus SG-8R36 & Alfine SG-S501
IGH cogs (Shimano, Sturmey Archer) are 3mm thick at the base.These cogs are held in place by the snap ring.
To get desired ratio, plan on using 8-and 9-speed cassette cogs after grinding away 6 splines and shaping the remaining 3.
Only when Shimano & Sturmey Archer cogs with required teeth are unavailable.
8-speed cogs are 1.85mm thick.
9-speed cogs are 1.78mm thick.
How thick should spacers be for the snap ring to hold the cog in place?
Obviously, it is 1.15mm and 1.22mm but spacers of that thickness are unavailable.
Do the spacers need splines?
What did you use?
What do you recommend?