The 12s in the front will make it harder to steer. As far as slowing it down it really depends on how aggressie of a tire you choose.
Tires do not really matter on the IRS vs SRA, I was refering to the offset of the wheels. IRS bike basically use 4 Front wheels (same offset). While the SRA uses different offsets front and rear.Tires matter when it comes to IRS?