This is normal for Sundia diabolos. There is a tiny gap between the axle and the hubs so the cups can spin independently from the axle. It does not affect performance and can be ignored.

Yes, single EVO cups in soft or hard are available on the site. A single cup for other models can only be ordered by email for now, at 14€ per cup: send your request to info@diabolofocus.com.

Paraffin (lamp oil). It burns cooler, cleaner and longer than other fuels. Never use petrol: it is far more volatile and its vapour can ignite away from the wick.

Soak the wicks for a few minutes, keep several tight layers (ours come with four), and put the flame out before the wicks run dry. A dry wick burns its own fibres and wears out fast.

Every extra layer burns longer and brighter but adds weight, which makes the diabolo slower to spin and harder to throw. Ours come with four layers as the balance; for short routines or more tricks, use fewer.

Spin it off before lighting: shake or spin the diabolo over the fuel container, well away from the place where you light it, so no drops fly off burning.

Smother them with a damp fire blanket or a cotton towel. Keep it ready, together with a fire extinguisher, before you light.

When they fray, leave a grey residue, or the burn gets clearly shorter. The wick is sold by the meter; one meter covers the whole diabolo.

The Aluminium Fire Sticks with aramid fire string. A normal string melts in the flames. Soak the fire string in water before each session.

Yes, and you should. At 500 g with the wicks it is much heavier than a normal diabolo, so learn your routine unlit before you light it.

Dip the string in a bucket of water between runs to cool it. Keep the diabolo moving along the string so its hot centre never rests on one spot. Like a guitar string, a fire string wears out in the end, so keep a spare.

Yes, with care. Keep your back to the wind so the flames blow away from you and from the string.