Just completed building my S120.
Wow!! What a kit. The more you look at the car, the more you see that a lot of thought and planning went into the design. The detail is incredible and most everything assembled perfectly. There where only two issues:
The outside of the diff: The thrust bearing is an old school system that we used many years ago. This system works very well and allows the outside hub bearing to last much longer because there is no damaging side load on that bearing. Brian Bodine makes a thrust bearing that will probably work but I think that with a little tweaking, the kit thrust bearing will also work. I did put in 1/8th diff balls which helped a little but I think the aluminum cap that goes over the carbon part of the axle is not deep enough and contacts the axle when tightened down.
The only other issue is the center shock spring. Only one came in the kit and there are no other springs on the market that fit that shock. I have hundreds of different springs and I tried them all, 1/12th to 1/10th and nothing fit. Hopefully they will come out with their own line of springs as the shock is a beautiful piece.
I placed my new S120 on the bench next to my 12R5 and the 12R5 looks like a toy car. The S120 looks like a real racing machine. I fully understand the reason for the price and quite frankly, I am surprised it is not more than it is. Now if only it will perform as great as it looks. I will find out on 11/22.
Well done, Serpent!!!