Puch rear sprocket

Reed Hois /

Feb 24, 2020 08:26PM

Hey y'all, my puch magnum xk is finally ripping. I am getting registration soon, and I live in the chicago area. Now, my magnum has tons of upgrades, and i just did a top speed run. 45 mph, not bad, and it has impressive acceleration from a dig. Its 16x40 gearing, previously 16x44. In my area, most the speed limits are 35, but since it is urban everyone does 40-45, which is close top top speed for my ride. If i went with a 36t sprocket would I be able to tell a huge difference in acceleration? I enjoy some good pulls, but 50mph top speed is where I want to be at. should I stick with a 40 or would it be fine to go 36t?

Thanks

Re: Puch rear sprocket

Probably Fred /

roffman

Feb 25, 2020 03:34AM

Ya your right you need to go 5-10mph faster then speed limit to be safe in traffic

What is your setup (kit/cylinder type and cc, pipe, carb, clutch etc.) and how much power do you think you make?

If your bike is kitted it should be able to pull 17x40 gears (Changing countershaft engine sprocket is easier then rear wheel sprocket) 16x36 maybe too much gear,

Most mild 70 cc piston port setups I do with 14 mm bing, circuit/estroil pipe with tuned clutch and jetted and tuned correctly can pull 17x40 gears and hit 47-48 mph with good takeoff and do ok on hills,

But that’s me, the speed you want depends on your setup, how good tuned you are, your powerband, (how much hp and torque you make at what rpm) and how tuned your clutch is,

This may help you figure gearing but you still need to make power and tuned clutch to pull taller gearing,

https://toolbox.martysgarage.info/

Re: Puch rear sprocket

Nate K /

wisenuts

Feb 25, 2020 08:35AM

I'm in the same boat. currently my mag does 41 top speed on stock gears. 70cc treats v1 kit - (i believe no porting - no case match - haven't opened it up), 15mm bing(76jet), stock crank, circuit pipe, dunno bout clutch, high flow air filter

got 17t front,40t and 36t rears coming from treats. i'd also like to top out at about that 50ish but fear the stock crank - so i'm trying to keep it at or under 9k rpm (16x36 is what i'm going to try first)