Most of those motard wheel/tire setups have 12" wheels and will not work with the stock forks or swingarm, for a variety of reasons.
1. 12" wheel won't fit in the swingarm
2. 12" front motard wheel won't fit in between the front forks
3. Both wheels use disc brake setups
4. Most motard wheels are at 1.85"/2.15" fronts and 2.15"/2.50" rears. Stock rims are only 1.40" wide.
A pair of IRC MB38 tires will work just fine on stock rims
1. 12" wheel won't fit in the swingarm
2. 12" front motard wheel won't fit in between the front forks
3. Both wheels use disc brake setups
4. Most motard wheels are at 1.85"/2.15" fronts and 2.15"/2.50" rears. Stock rims are only 1.40" wide.
A pair of IRC MB38 tires will work just fine on stock rims