Trakhak

A current thread where someone is debating modifying the gearing on a cruiser bike (by changing either the chainring or the sprocket) got me thinking. Why are threaded hubs the standard for single speed and track versus the hubs that take circlip-style single-speed sprockets?

Cheap 1/8" coaster-brake/circlip-style sprockets are available in a wider ranges of tooth counts than screw-on sprockets, and interchanging them requires only one non-specialized tool (e.g., a flat-blade screwdriver or the equivalent) and almost no effort versus the need for a lockring wrench, a chain tool, and lot of grunting.

I've been riding fixed-gear bikes since 1964, and I don't know why it never occurred to me before to question the logic of using screw-on sprockets that become progressively harder to remove the more you ride the bike. At nearly 70, I find that my arms and legs are weakening at nearly identical rates, such that I can still unscrew the sprocket, although just barely, but I wouldn't be averse to taking arm strength out of the equation.

I know that there are adapters available to install a slide-on sprocket plus spacers on a freehub, but there should be a high-quality fixed-gear (or single-speed) hub with the same mounting system.

Rolla

For singlespeed hubs with a screw-on freewheel, just put the FW tool in a vice (prongs facing up), lower the freehub onto the prongs, and turn the wheel like you're driving a bus. The wheel diameter gives you plenty of leverage to easily dislodge the FW.

For a fixed gear, I wouldn't trust a snap ring over a reverse-threaded lockring, especially if I was riding brakeless. I've seen too many coaster brake cogs develop play in them, and those snap rings are just cheap spring metal.

Breaking a threaded fixed cog free is usually just a matter of using a long enough lever.

Russ Roth

White industries uses a spline style cog on their fixed gear and miche sells an adapter that you screw on that then takes splined cogs. If I start doing well enough to justify it I might build myself a set of the WI hubs to some light carbon rims for a faster wheelset, kinda like the idea of easy swapping.

JohnDThompson 

I think it is mostly tradition. Double-threading of track hubs for a sprocket and lockring is an archaic kludge. There are modern track hubs from White Industries, Halo, and possibly others that use a splined sprocket retained by a standard right-hand thread lockring.

TejanoTrackie 

You can also just clamp the handle of the chainwhip in a bench vise, place the fixed cog in the chainwhip and turn the wheel. That's what I do when I can't remove a cog directly with the chainwhip.