- Improves balance and control and the ability to ride straight ahead, translating into greater efficiency, strength and technique on the road. - Safe and sturdy: the bike castors are made of aircraft-grade aluminum alloy for improved stability and safety; symmetrical bearings help keep your ride balanced. - Bike compatibility: supports 24-27.5 inch mountain bikes and 700C road bikes; provides ample freedom of movement; even through winter, maintaining training habits keeps your cycling better. - Portable design: foldable for easy storage and space saving; after training you can quickly tidy the venue when you are tired. Use scenarios - Indoor winter training to maintain cadence and technique when outdoor rides aren’t possible. - Limited-space home setup, easy to fold and store between sessions. - Skill development for balance and straight-line control to boost on-road efficiency.