You should consider the base oil viscosity when selecting a grease. The NLGI number or type of thickener is only part of it. The "issue", if there is one, is that the operating speeds are very low on a bike, thus requiring a very viscous base oil, not common in general purpose greases. - And you cannot infer the base oil viscosity from the NLGI number. Luckily the loads and temperatures are very benign, meaning you can get away with most greases anyway.