Tyre inserts aren't new, but Spin Shield has a new spin on the concept with a low-volume system that mountain bike legend Nico Vouilloz is promoting.
While a lot of inserts take up the majority of the tyre's internal volume, the majority of the Spin Shield system sits down inside the rim.
The system should be a touch easier to fit, as there's less insert to wrangle inside a tyre. Plus, the system should offer less interference with the inherent feeling of the tyre compared to larger-volume inserts. And finally, it allows a bit of flexibility with how the insert is used.
The system has a central foam ring that sits in the well of the rim, and two wings that push towards the tyre sidewall. The foam ring should help keep the tyre seated securely in the rim, while the wings are there to protect against pinches, and aid tyre stability, Spin Shield claims.
Installation is done with a single length of foam. The central section of the insert is pulled in to the well of the rim once both beads of the tyre are fitted, securing them in place, through the tightening of the valve. This should be easier than squeezing the bead of the tyre in to place with an already tensioned insert there.
As for the feel of the tire, other insert brands claim the ride feeling can be enhanced by an insert, but Spin Shield argues that the tire's construction and the rider's chosen air pressure should dictate ride feel.
In any event, since there is so much space left in the tyre, you can run additional foam inserts if you like, or just run it tubeless as it comes. You can also run the system with inner tubes, and Spin Shield claim the same puncture protection benefits.
With a claimed weight of 215-260g (depending on wheel diameter and tyre width) it's in the same ballpark as other notable inserts, and Spin Shield claims it won't absorb sealant.