Fancy switching to singlespeed – maybe for winter – but don’t want to shell out for a new wheel? These spacers slide over your cassette hub so that you can put a single sprocket on the back.
One benefit, apart from cost, is that you can use any sprocket from 11 to 34 teeth. That’s a much bigger range than is available with threaded singlespeed freewheels, which generally come in 16, 17 and 18-teeth only, but you’ll need to take a cassette apart to get that sprocket, or buy one from the likes of Surly or Londonfixiebike. Plus you’ll still need some way to tension the chain.
We were sceptical that the chain would engage well on the 12 tooth sprocket (pictured), as the underside of the chain rested on the spacers, but it worked fine without slipping, though we would still use a bigger sprocket (15 teeth plus) for peace of mind.
The CNC machined aluminium spacers come in a set of seven in different widths, so it’s easy to get any chainline just right. The set weighs just 25g.