Not quite BMX but almost. Rear wheel/cog issue

[Gal]

Hi.
Ok not quite a BMX.. but a 24" jump bike with horizontal drop outs and bolt through hubs. At the moment running the usual front and rear gear like most BMX's, but want to add the smaller chain ring ( easy to do ) and also rear. Cycles uk or whatever they are called say I cannot do it unless changing rear hub, which to me means new wheel minus the rim because its integral to the hub. Surely the is a way to take it off and maybe add some adapter? Or is me me and my untrusting ways with larger companies trying to get as mych cash off you as poss? Goes back to the day I picked up my 1st BMX age about13/14 and on the way home the rear cog suddenly just span, not spinning the wheel. Local shop said need new wheel!!! Took it back next day to where I got it and with a thump from a hammer and hole punch it was fine

[Dark Diggler]

The smallest individual cog that can be spaced in or out (for chainline) on an mtb hub is 12T, the front sprocket would need to be a 28T (on a 24" wheel)
You can use the 11T of an MTB/road cassette but it would have to sit next to the lockring, like it does on a cassette, this may give an odd chainline, then you can use a 25T at the front. I used 30T and 13T at the back on my 24 and found it fine for skateparks and dirt

Hope this helps

[Gal]

Thanks. I think I need to read up on bike mechanics as not really taken much to do with bikes since the 90's! Knew what I was doing then