Harley-Davidson (NYSE: HOG) isn't the only American motorcycle company hit by the retaliatory actions of the European Union for tariffs President Trump imposed on imported aluminum and steel. Polaris Industries (NYSE: PII) is also looking at moving its Indian motorcycle production overseas, though it says it is also studying a "range of mitigation plans."Yet as difficult as the higher tariff costs will be for both of these bike makers (not to mention increased domestic raw-materials expenses), Polaris may be the one put at a greater disadvantage.Not only are motorcycles getting whacked by tough new import duties, but the EU, Canada, and Mexico have all imposed higher tariffs on boats.