hereEmergency services attended and found that a 20-year-old motorcyclist, on a blue Suzuki motorbike, suffered a serious injury.A cyclist - a man in his 50s - was rushed to hospital with life-threatening injuries.He remains in hospital, Greater Manchester Police said.A 20-year-old man has been arrested on suspicion of causing serious injury by dangerous driving.Officers are now appealing for witnesses to the collision.Sergeant Joe Barron, of GMP's Serious Collision Investigation Unit, said: