Road tyre inserts

What does a tyre insert do on a road bike

The insert sits inside the tubeless tyre and fills the central space. On a road bike, it addresses two separate problems: protecting the rim from an impact with a pothole, and allowing you to finish a ride with a flat tyre without riding on the rim.

Three uses, three reasons to fit one

• Protecting a carbon rim : that’s the main reason on the road. A cracked carbon rim costs far more than a pair of inserts.
• Riding with a flat tyre : after a puncture that the sealant hasn’t sealed, the insert lets you ride several kilometres home at reduced speed without ruining the tyre or rim.
• Lowering tyre pressure : in cyclocross and on cobbles, the insert allows lower pressure without the risk of pinch flats, giving you more grip and comfort.

Choosing the right size

• Air-Liner Road S : 700x23 to 26c. M : 700x27 to 29c. L : 700x30 to 32c.
• Air-Liner Light covers wider tyre sizes — 700x28-30, 32-36 and 38-42 — in a lightweight version for gravel and road riding on wider tyres.
• Air-Liner Cyclocross is sized for 700x31-33 tyres.
• An insert that’s too small moves around inside the tyre and offers no protection; one that’s too large prevents the tyre from seating on the rim.

The trade-offs

An insert weighs between 40 and 90 g per wheel, as unsprung weight at the wheel’s perimeter: that’s where weight is felt most. It also makes fitting more difficult and slightly reduces the air volume, and therefore the tyre’s cushioning effect. On a pure racing bike, it’s a questionable trade-off; on a set of carbon wheels used every day, it makes good sense.

Tyre inserts and sealant work together

The insert doesn’t replace sealant; it complements it: sealant plugs small punctures, while the insert absorbs impacts and protects the rim. The inserts Odyssey Optis are available in a dual-valve version, allowing separate inflation and control over the internal pressure.

To find out more: What pressure should I use for my bike tyres

See also: Road tyres · Road tubeless valves · Cyclocross tyres