Gear Hub fan
Join Date: Nov 2008
Location: Reno, NV
Bikes: Civia Hyland Rohloff, Swobo Dixon, Colnago, Univega
For service as intermittent as an air horn there should be no problem IMO. Automotive 12V motors routinely run at 13.2+ volts which is the actual output of a 12v lead acid battery when fully charged and the car alternator output is above that in order to charge the battery, usually in the 13.6v to 13.8v range as I recall.
Gear Hubs Owned: Rohloff disc brake, SRAM iM9 disc brake, SRAM P5 freewheel, Sachs Torpedo 3 speed freewheel, NuVinci CVT, Shimano Alfine SG S-501, Sturmey Archer S5-2 Alloy. Other: 83 Colnago Super Record, Univega Via De Oro
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