Textron Off Road ATV Forum

The only 550 manual we have in the downloads section are:  

My `1991 Honda Fourtrax 300FW  actually calls for  1 "  smaller tires  on the   front than the  rear ....  23" diameter  on the  front  and 24" on the rear  because of a slight difference  in the  gear ratios in the differentials. . That being  said most, including  me  run  the same  size tire  all the way  around.   The  gearing  is close  enough  and since  quads are seldom  ridden  on pavement or hard surfaces  that  prevent  tire slip   we don't  have a problem with drive train  binding.   Yes,  it is  "normal"  to  have tire sizes  front and rear the same  on 4x4 trucks and SUV's but it  is not necessarily  so  on  Quads ,  tractors and some other off highway  equipment that are  4 x4  or all wheel  drive. I  don't  know the specs  on other  machines. That is why  I  suggest  checking  because although  the same  size  is  normal  all  the  way  around  but  if  a machine  for some reason  uses  differing ratios  it  can  cause  binding  and  breakage . I would  guess  newer  machines   would  be the same all  around  but double check  yours  to  find out. It doesn't  hurt  and can save  grief  down the road .  

Are you sure about that code number ?

4x4s in general have the same gear ratio front and back unless specifically designed otherwise.  All four wheels have to rotate at the same time with cars and trucks as well. So unless there are specific builds then yes same size tires are required.   

It depends on the  quad whether  all 4 tires are the same .. Check  the owners manual   or  online .. Some have a slightly different  gear ration front and rear  and  use smaller tires on the front .