But the oem rear wheel is also wider so wouldn’t you need to account for that with the spacer as well as the 20mm of offset. Sorry for all the questions, i hate figuring out offset, backspace and width, it confuses the crap out of me!
You are over thinking it, first you are not using 6" front wheels / 9" tires and 8" rear wheels / 11" tires, you are replacing all with 7" wheels with same width tires. Therefore only the difference in offset of wheel center is needed to correct the wheel track. Historically without spacers you would be 2" narrower in rear than front. So 1' spacers get you very close.
Sweet, thank you for the help. Can I ask anither stupid question? When I did wheels and tires for my on road vehicles I just had to know what backspace and offset to order and offset is measured in mm and most of the time backspace was measured in inches. So my truck has 4.5” of backspace and -12mm offset. What is 6-1 or 5-2 mean on these ATV wheels? Don’t mean to sound ignorant!
7" wheels are either 6+1, 5+2, 4+3 offsets typically. Hence 5"+2"=7" which is 2" out from center, that's typically the most popular except for mud bugs who need / want more clearance for really wide tires so they typically get 4+3 offset.
Wow, great discussion on wheels. I too am looking to change my wheels and tires to 30 x 10 x 15. It sounds like it all worked out for you on the offset and spacers would you mind tell me what rims and spacers you used?
STI HD9 14" in the 6+1 or 5+2 offset are known to clear the brake caliper and upper control arm on the front of an X (they will clear an R but removing some material from the upper control arm is recommended). It is not known if the System 3 14" will clear.
