Ray-JrMALL MR.Jiang Bike Trainer Accessories Riser Block Front Wheel Holder Why do we need the front wheel stabilizer. Since the bike trainer will lift the rear wheel, thus the bicycle's level angle is adjusted to the rear wheel high, front-wheel low, not suitable for long-term riding exercise, and in this posture, it is likely to cause hand fatigue, this special front wheel stabilizer is developed. Material:ABS. Package includes: 1 x Front Wheel Support