hey guys im new to the forum i used to be big into trail riding and downhill stuff well here not to long ago i sold my big bike and went to a 20 incher well after riding park for a while im getting preatty good on the 20 but it just dont feel right to me i have noticed a lot of guys riding big bikes with street tires and all on them and it looks like a blast to me i have some stuff laying around to build one up but i dont know where to buy parts for the more park related bikes, what im thinking i want to build is non suspension bike, street tires, disc brakes, maybe a 25-9 setup, but i cant find anywhere that sells it for big bikes
is there anyone here that knows where i can find parts for urban mtn biking?
If you mean the 9 tooth cog, you'll need a BMX cassette hub custom spaced to a 135mm dropout frame- not easy or cheap. Try an 11 or 12 tooth combination, all the other parts are standard MTB parts, available at myriad retailers.
There are a few ways to do singlespeed on a mtb, some cheaper than others, but they all work quite well. I'd recommend browsing sheldonbrown.com for a good idea of the different ways it can be done. Good luck with your build, should be fun!