In heavy traffic, 2 hours or more of stop and go (I90 pass over the Cascades in the summer coming towards Seattle every Sunday) will do it. If the bike is moving you will seldom if ever overheat. On the road, 115*F no problem at all for the bike. The BMW oil cooler fan for the police model bolts right in for a couple of hundred bucks. You need to add a control switch/power as the stock bike does not have the wire harness to make it work right off the top. There is also a shroud that you need with the fan. Look on the Max parts fiche and you will find it with a little hunting.
01 46637690869 FAN SHROUD $26.85
02 17117656030 FAN $237.83
03 07119931026 WASHER - 3 $1.16
04 63127682829 SCREW - M4X12 3 $1.54
05 61131367599 CABLE STRAP - L=200MM/B=3,6MM 1 $0.50
06 46637659459 OVAL-HEAD SCREW WITH ANTI-ROTATION LOCK - $2.00
07 51127070202 CLIP NUT - M6-ZNS3 2 $1.1