Mountain biking in Riyadh

Dear All,

I would like to start exploring some mountain bike trails in or near Riyadh. But, first things first, I still need a proper bike. I´ve already been to Wheelers, apparently the only bicycle shop in town, but I would also like to know if there are any second hand opportunities available.

Does anyone have or knows someone that has used mountain bikes for sale?

Thanks.

Paulo Andre