Hello, After see my nephew learning trial, i decided to build my own, to do some easy tricks and ride at park with my son and/or nephew when I'm not alone (in this case I would ride my mountain bike) I'm in bad shape, a bit old for some things, thats why i had buy a cheap 26" frame with seat post, to rest my back between tricks. Can anybody suggest me online shops where i can find the rest of spares i need? Basically i will need a rear wheel, all the transmission, integrated ahead, and something more. Thanks in advance, Paco PS: excuse my English, I'm Spanish