Carl-Erik Renquist wrote:
Here's pictures of the different versions of gears. Early Scout with 30-40-77 teeth count, 101 Scout and 22-31 Chief has the same gearing 33-36-84, but different shaft diameter, and later Chief and Std Scout with 39-36-84. I don't know the shaft diameter of the 39 cog gear.
33 cog Chief gears might have had a larger diam of the shaft taper in years pre -28, and same taper as the 101 in the same years, but I am not sure.
Courtesy of Ralf Spindler, shown is a Chief 33 cog gear on a Scout shaft.
In order to fit the 39 cog gear without changing the 36 cog intermediate gear, the case is a one, two, three year special...before the chain transmission was implemented.
I think the idea with the 39 cog is to speed up the gearbox gears in order to even up and lower the thrust impulses from the engine, and make the gears in the gearbox last longer...And also compensate for the large chain sprocket needed on the brake drum..
Hi Carl-Erik,
sorry for the late reply, but i had very important family stuff to sort out and couldn't take care of my motorcycles for the past few months.
Thanks for all the info.
The shaft of my crankshaft is the larger one which is used in later 101, Sport Scout and Chiefs.
With the 39 teeth on the crankshaft the gear ratio in the primary is 2,15 which is quite the same as in after 33 models with the chain primary drive which is 2,16.
I think it's like you said with the speed of the gears in the gearbox and the greater sprocket around the brake drum.
And aditionally after '33 the road conditions getting better and average speeds gone up higher so the factory used a completely new overall gear ratio.
Unfortunately I couldn't find a good original 39 teeth pinion gear but Mark from Crazy Horse Indian Australia has one of these in non usable condition as a sample and now he'll ask the guys in Australia who reproduce the scout gears he has in stock if they could do a small series of the 39 teeth version as well.
When everything will run well I'll get a new one in the next weeks.
I'm really looking forward to that.
But thanks a lot to all of you guys who helped me out with pictures and the needed information!!!
All the best
Manny