The bike frames are made of magnesium alloy, it has much more advantages than thealuminum alloy bikes, such as light weighted, high strength; noise absorption,shake absorption, electron shield etc. It is a new for bikes.If you have any questions regarding our magnesium bike frames, please do not hestitateto call us. Yuandong is a manufactory that you can trust to manufacture yourproducts with great care and quality at the right price and we guarantee timelydelivery. producing area:China payment:L/C supplying capacity:200 pieces per day