Get a bit more speed, and more useful gears, from your KPM!
Unlike some newer KPM 200’s, mine came with a 15t front sprocket. That gave the bike a good amount of torque for small engine, but at the cost of the flexibility of having 6 gears! To give the bike a bit more breadth, I switched to a 17t sprocket. Why didn’t I do this sooner?
- 1st, 2nd, 3rd gears much more usable now … I can actually stay in 1st gear a bit longer. Now cruising around town in 4th or 5th, as opposed to 6th.
- Much smoother overall, doesn’t feel jerky anymore between gear bands.
- Highway performance much improved – I was in 5th gear comfortably up to 65, hitting about 7500 rpm. Much nicer, less vibration and unease from the engine at those speeds. Didn’t take it up past 73 because of traffic, but it had a bit more room up there.
I’m a heavier guy, and this is significantly better than with the 15t. I assume Lifan goes with that gearing so it feels snappier and you don’t notice it’s a 200cc engine, but honestly this sprocket swap is a must-do after exhaust change.
How to make the swap
This is a pretty easy swap. I give this 2 wrenches out of 5 in terms of difficulty. The basic steps are outlined at right.
Before & After Stats
Stock:
Front sprocket: 16t-428 (20mm shaft)
Rear sprocket: 49t-428
Chain: 428 128links
Final gear ratio: 3.0625:1
Top speed: 75mph (under ideal road conditions)
MPG: 89mpg
With 17t front tooth:
Front sprocket: 17t-428 (20mm shaft)
Rear sprocket: 49t-428
Chain: 428 128 links
Final gear ratio: 2.8823:1
Top speed: 82 mph (under ideal road conditions)
MPG: 109mpg
Info courtesy KPMRider on ChinaRiders.net
- First, loosen the rear axle bolt, and the two sets of retainer nuts that hold the rear wheel in position, located at the end of the swingarms. Push the rear wheel forward to loosen slack on the chain.
- Remove the cover (shown removed in photos above) that covers the front sprocket. The front sprocket is not lubricated directly, it takes its lubrication from the chain!
- Remove the two retaining bolts holding the brass-colored sprocket clip to the sprocket. Twist and remove the retaining clip.
- Remove the sprocket, being careful not to pinch your fingers.
- Attach the replacement sprocket in reverse. The sprocket clip should sit in a groove in the output shaft. Twist the clip so it locks the sprocket in place, and tighten the bolts.
- Now adjust the free play of the chain. Move the rear wheel forward or back until you observe approximately 10-20mm of slack as you move the chain up and down from its midpoint. You can find the midpoint of the chain by measuring from the middle of the output shaft to the middle of the rear axle. Measure the slack movement from that point, and just the wheel until you have about ~15mm or so of slack up and down.
- Tighten the retainer nuts at the end of the swingarm on the sprocket side. Make note of where the middle of the rear axle falls on the swingarm. There are ‘tick’ marks etched into the metal of the swingarm. Now match the other side of the axle to the same mark.
- Tighten the adjuster on the other swingarm, then tighten the axle. You should double check the adjusters again to make sure the two bolts are snug to each other.
2 Comments
Benjamin Seifert · August 25, 2023 at 11:35 am
Mine came with a 16t and didnt realize this til i swapped to a 17t. And 17t with stock tires was great got it up to 80 (screeming but did it) unfortunately after changing to larger dual sport tires i could bearly get it up to 65 after that and lost any power in 5th and 6th gear. I chose to switch back to my 16t and am able to get that 75 and have a little power left in the flats.
admin · August 25, 2023 at 1:09 pm
Thanks, Benjamin! Good to know. Would love to see a pic of the dual sport tires you threw on there!