Bolt on (ISO or otherwise) cogs/hubs

Anyone here running them?

A few threads seem to refer to bolt on cogs, but they don’t seem to be as popular as I would think they should be. I was checking out velosolo and found a few variations.

They do one with a shimano deore XT front disc brake hub. Phil Wood has one (single sided and double sided bolt on). As do a few other manufacturers.

I was wondering if they would be track legal for racing? Not because I want to race with one, just interested to know.

I’m having one built up atmo, I got a generic 20mm thru axle mtb front hub off ebay and am lacing it to a velocity deep v. Hub is a red anodised ‘Novatec’ branded thing.

I’ll get an axle and spacers machined up to suit, I’ll post some images once it’s done.

No idea about legality for the track, but surely it would be fine?? No more stripped threads. and stupid lock rings hehe. Only limitation is the minimum tooth count on the sprocket, which is 15 from my memory.

Did cycle underground ever get their bolt-on cogs into production?

I tinkered a bit with doing this on the cheap with a 135mm MTB-hubbed wheel in a flip-flop style (bolt on sprocket on disk side for fixed, ss conversion sprocket & spacers on the freehub side).

Chainline was difficult to get right for both sides of the hub and and meant a chain ring on the outer posi on a mountain triple crank plus an extra long BB spindle. It all felt weird and got too hard so I built a new wheel with an Eno.

I think the purpose built hubs would be miles better, at least for a track bike (proper 120mm spacing). From memory the Phil Wood hub looked about AUD$230 before shipping.

With the track question, I was thinking more about any rules that would cause it to fail (e.g. “cog must have reverse threaded lockring screwed on” or something like that).