Some bags might not be compatible with your motorcycle. Bags that are rectangular in shape do not normally fit bikes with upswept exhaust pipes. A clearance of at least 2 inches ought to be maintained between exhaust pipes and bag bottoms.
Also check out the Dirtsack Heat Shield, listed under accessories on our site. We use it on all our bikes, ranging from the Himalayan to the KTM 390 ADVs and also the Triumph Tiger. The heat shield provides a physical barrier between the hot exhaust pipe and the bottom of the bag but direct physical contact is still to be avoided at all costs.