Dragon Chopper (3/4 chopper)

[Kingdiamond20]

Btw I will be making a Facebook page labeled chinariders after I create the page I’ll come back post the link, since not many use this forum anymore

[Kingdiamond20]

[ATTACH][/ATTACH]

[culcune]

Exhaust will gain a slight power boost, a carb, as well as a Zonshen ported head from CSC. Gearing, even before trying to add power, should get you some speed. There is not much to be gained from the engine itself (the head is relatively new), as most people with these thumpers have shown on the dual-sports section; carb, gearing, and exhaust to start.

[JerryHawk250]

Culcun pretty much got it covered. Most of the mods would be the same as the Hawk and Brozz, etc.

[Kingdiamond20]

Looking to upgrade sprocket for this chopper I want to go from a 15T to a 17T for top speed what’s y’all s advice? Where can I buy one ?

[culcune]

Originally Posted by Kingdiamond20

Looking to upgrade sprocket for this chopper I want to go from a 15T to a 17T for top speed what’s y’all s advice? Where can I buy one ?

Since the engine is common 223cc Zongshen thumper, they are all over Ebay and I am guessing Amazon. Same as XR150 I believe? Someone should be able to clarify. The only possible issue is the cover for the sprocket. Since every engine that Zongshen OEMs for is proprietary to that brand as far as EPA is concerned, there are some brands that people have had to modify slightly to accept 17 tooth sprockets. They are low cost enough that you could order both a 16 and 17 to play around with. Not sure if a 17 will make you have to worry about chain size...a 16 should not necessarily be an issue as far as size and chain size go. You might want to start there.

[JerryHawk250]

Originally Posted by Kingdiamond20

Looking to upgrade sprocket for this chopper I want to go from a 15T to a 17T for top speed what’s y’all s advice? Where can I buy one ?

I think you will be fine with the 17 tooth. Most of these bikes come geared too low from the factory. What's the tooth count on the rear and rear tire size?

[Kingdiamond20]

A 16T ok I’ll start there, and jerryhawk I’m not sure what the rear is I’ll find out for ya ty !!!

[JerryHawk250]

just looking at pictures of the bike it looks like the rear is anywhere from 42-45 tooth and with the 205/40-14 rear tire I would go with the 17 tooth. That will still be a low gear ratio compared to what most are running on the Hawks and similar.

[JerryHawk250]

Here's a sprocket calculator. https://www.gearingcommander.com/ You can use the Hawk to start with as it has the same gears in the transmission. Most are running 17/45 sprockets to give you something to compare to. All you have to do is enter the correct tire and wheel size which yours is 205/40-14. I looked it up on Venom Motorsports site.

[Kingdiamond20]

How much of a top speed increase shall I expect by upgrading to a 17 T sprocket?

[franque]

About 13%, theoretically, assuming it has the power to pull the bigger sprocket.

[JerryHawk250]

Originally Posted by Kingdiamond20

How much of a top speed increase shall I expect by upgrading to a 17 T sprocket?

Not sure what your rear tooth count is but probably 5+ mph.

[Kingdiamond20]

I guess that’s better than none put me at 55 mph

[JerryHawk250]

You can also swap to a smaller rear sprocket later if you need a little more top end speed. What rpms are you hitting at WOT? Are you hitting the rev limiter?