I did this to my Z120 and so far i have been happy with it and have about 50 miles on it so far, I will make some minor upgrades an the need arises.
That is a great upgrade, Im new to having a z120, its for the grand kids but I find the chain drive really noise and annoying. I think your friend could make some $$ on the side if he was willing to make that front sprocket to pulley mod for others.I did this to my Z120 and so far i have been happy with it and have about 50 miles on it so far, I will make some minor upgrades an the need arises.
We ran this about 50 miles so far and have had little problems, the belt has come off just a couple of times but i think the outer lips would help that. I have not noticed any slippage and the belt look good so far. it is going to get parked for the year in a couple of days so that is about all the testing it will get this year. We did a trip to our cabin with it and it is ten miles one way off grid, we got 36 inches of snow that weekend and had zero problems with the 120. here is a link to the video i made of the trip if it works don't know if its alright to post it here.Wow, awesome idea. I agree this needs to be picked up by someone, as that chain drive is nothing but garbage. Perhaps Midwestern would be interested in including this to their offering of speed kits. One thing though have there been any problems with the belt slipping at all? And yes agree on an upgrade to an aluminum the pulley with the machined cogs being recessed to offer outter lips to reduce the chance of the belt slipping off.