You most likely have a lean backfire that caused by an intake leak. The engine has high vacuum under deceleration, which will magnify the leak. If you had a partially clogged jet, the bike would most likely have a flat spot somewhere in the acceleration curve. Warm the engine for a couple...
My wife and I tour the rockies with our 2006 Bonneville. Both of us with gear and saddlebags full are about 400 pounds. The rear shock springs are fully cranked up and the rear is fine except for a somewhat rapid rebound. The forks, however, are too soft, especially when rapid braking is needed...
Bonneville tires
Hi: A good Triumph dealer here in the US recommended the Pirelli Sport Demon tires and they are far superior to the stock BS BattleAx's that came stock on my 2006 Bonnie. The black tar "snakes" in the road are no longer noticeable, tires are way smoother and hold far better...