I belive you need more than 145 teeth total and no more than 152.
4/2.0588=1.943
147/1.943=75.6, But we need a hole number there so if you have a 75 tooth use that one.
75/1.943=38.6... ok 39
39+75=114
Ok so we need a small spur gear , But thats not going to reach with that gear combo. Let's try about 25% more.
93/1.943=47.8 ok call it 48
93+48=141 .... not quite enough teeth just yet. Only need a few more to mesh. I dont like running repeating grear ratios like 2.0 as its wears out the gears faster so ... lets try this one more time with a 99 tooth.
99/1.943=~51
99+51=150 Awesome and 2 teeth to spare on the pinion. We can always fine tune it with the spur gear too. But there you go
99 spur /51 pinion = 1.9412
1.9412 * 2.0588 = 3.996 I' call that a 4.0 final....
99/53 is a 3.85 so If you buy a 99 spur get 51, 52, 53 pinion.
Remember try to keep the total amount of teeth between 145 and 152!
