I have looked through some papers by Cossalter et al. Some are about 
experimental work, some about tire modelling. A paper about actually 
deriving the equations of motion is 
V. Cossalter and R. Lot (2002), 
'A motorcycle multi-body model for real time simulations based on the natural 
  coordinates approach', 
Vehicle System Dynamics 37, No 6, pp.423-447. 
In this article, a model with 11 degrees of freedom is described. The 
equations are formulated as a large system of Differential-Algebraic Equations 
(DAEs). Furthermore, a tire force model is described, and a full set of 
parameters values for an example motorcycle are given. 
We can make a reference to this article. 

JPM, Nottingham, 8 Nov. 2005.