The gap don't look to good but another reason I'd think twice about using this tyre is you would be loosing a bit of ground clearence up the front. We know what scraping up the front leads to.
Put a Bridgestone on the back and it sort sort of counters that (I know, not completely and mainly in the centre of the bike) but I can't see it being a major issue for someone your size Bruce. Plenty of blokes that weigh 50kg more than you riding who will lower the bike more than the 15mm (1/2") the tyre does. They get by. Plus don't forget the back's 12mm higher if you put a 55 on there.
Put a Bridgestone on the back and it sort sort of counters that (I know, not completely and mainly in the centre of the bike) but I can't see it being a major issue for someone your size Bruce. Plenty of blokes that weigh 50kg more than you riding who will lower the bike more than the 15mm (1/2") the tyre does. They get by. Plus don't forget the back's 12mm higher if you put a 55 on there.