When I ride my Specialized Ruby Elite WSD size 44 cm I never wind up with chain grease on my right leg.

When I ride my hybrid Trek FX7.6 WSD size small, I always wind up covered with grease on my right leg. I have to really scrub to get it off. I have a much harder time getting off and on the hybrid.

Can someone tell my what I doing to make this happen all the time?

I don't want to wear longer bike pants/pants to avoid this.

Thanks