Front tires of LWB's not gripping well is caused by overinflated tires.

Many LWB's put 33% or less of the total weight on the front wheel, and a lot of people blindly inflate both their tires to the max PSI. This means that the front tire ends up being inflated to 2X or more what it really should be.

THe simple explanation is that when you are sitting on the bike, both tires should have the proper amount of wheel drop, no matter what width of tires you're using.