Reply to two tempos, one track, how may beat grids?

hey, i mix drum and bass but there are a few dubstep and house songs i also like. as you know the tempos are different,

I have a few songs which start at 174 and then have sections of 140, ideal spots to mix dubstep.

however the beatgrid is wrong at these parts as its too fast. is there nay way to make two separate beatgrids? so i can use these songs to convert from one bpm to the other?