VeloSolo is a UK manufacturer and distributor of singlespeed and fixed wheel specific parts and bits, a number of which can be found nowhere else (such as these converted front mountain hubs made to fit as rear fixed hubs with bolt-on cogs). One of their own pieces is the pictured 7075-T6 aluminum fixed cog, anodized gold just to make it sparkle. Manufactured in the UK by one of the leading custom motorcycle engineering companies, this is a high-end, lightweight and very round cog for those people that care about such things. The tested 17t cog weighs in at a mere 24g, as compared to 66g for a no-name 17t steel cog I had around for reference. While the 42g difference doesn’t sound like much, it is nearly one tenth of one pound, a not-insignificant amount for given bicycles. Compared to the usual steel cog there is certainly some weight savings, most certainly at the cost of longevity. Aluminum cogs simply do not last as long as their steel counterparts — the softer aluminum alloy tends to wear faster, especially with water and road grit in the mix.

The cog has a 7.5mm wide base with threads that are just so, spinning on easily and tightening down without binding. Care should be taken while installing this cog to be sure to get it tight the first time and to secure it with a properly fitted lockring as to prevent any sort of hub or cog threading failure — this is not a cog for people routinely complaining about stripping perfectly good hubs due to hamfisted installation practices. All of that said, after some 400 miles on this particular cog and minimal visible wear to the anodization my concerns over excessive wear have been put aside. I can’t say I’ve been gentle either, seldom a ride goes by that doesn’t have some sort of trail or railbed incorporated into the route. I foresee many more miles to come on this cog.

The VeloSolo cog is available in 15-19t sizes in either 1/8″ or 3/32″ depending on your preferred chain width for about $25, comparable to other higher end fixed cogs on the market.