JerryHawk250's Lifan KPX250

[Bill Hilly]

Originally Posted by bigdano711

Have you done a top speed run, yet? Very curious, us heftier folk are.

I haven't used GPS on mine, and from what I understand, the speedometers seem to read a little faster than actual speed, but on relatively flat ground mine likes about 63 indicated speed. When I say like , I mean the "sweet spot" were they seem to run unstressed, and easy, and steady with out being under heavy throttle. When my Hawk had the hotter motor, it's sweet spot that it liked was about 58 indicated, which would have been about 57, or a little over 56. It's speed O is very accurate. I'm back to a stock motor on the Hawk, and comparing the Hawk, and KPX on the main roads is a stretch. The KPX has the extra power, but also the extra gear , and the fact that it's a OHC motor that doesn't mind the rpm as much. It's still no power house, but it's more power, and the fact that it easily will run 55 in 5th, makes it a pretty good road bike for me. I have to weigh 275 with boots, and jacket, and other than the interstate the bike is adequate for my needs. I have actually been feeling guilty for riding my " new" used 2006 KLR650 so much , especially when I just run back and forth around here locally. That being said, I probably would not have bought the KPX if I had already had the KLR. If you are concidering a KPX, and can wait a couple months, then Venom may have a sale on the last of the 2024s like last year when I got my 2023 .. I think that with the sale, and the JerryHawk code, I got mine for $2800. I will also add that I had my KPX on the interstate once for a short run between exits, and it, nor myself liked it. I do remember hitting the indicated speed of 75mph

[Megadan]

Originally Posted by Bill Hilly

I haven't used GPS on mine, and from what I understand, the speedometers seem to read a little faster than actual speed, but on relatively flat ground mine likes about 63 indicated speed. When I say like , I mean the "sweet spot" were they seem to run unstressed, and easy, and steady with out being under heavy throttle. When my Hawk had the hotter motor, it's sweet spot that it liked was about 58 indicated, which would have been about 57, or a little over 56.

45-60mph is definitely the Hawk 250/Similar happy place when using a 17 front and mid 40's tooth rear sprocket. I actually understand what you mean perfectly. I call that the unstressed top speed.

Nice to hear that the KPX has a slightly higher sweet spot out of the box. That means it is definitely going to be a little more highway capable. That extra gear definitely has something to do with it, but the peak power output of the OHC engine in the KPX is more likely the reason it can cruise at higher speeds with less perceived effort.

[nogreaterlove]

Originally Posted by bigdano711

Have you done a top speed run, yet? Very curious, us heftier folk are.

Top speed on level run, 72 mph. I would agree with others that the sweet spot higher speed is 62ish. Keep in mind I am 325lbs

[ProDigit]

What rpm you're getting at 72mph?

If you do end up changing the sprockets, try a 17/40 setup. Should be close to 7-7.5k rpm. Not sure if the ohc runs higher rpms than the pushrod.

[JerryHawk250]

Originally Posted by ProDigit

What rpm you're getting at 72mph?

If you do end up changing the sprockets, try a 17/40 setup. Should be close to 7-7.5k rpm. Not sure if the ohc runs higher rpms than the pushrod.

Won't work on the KPX. The KPX uses a 520 chain and sprockets. Not enough clearance for a 17 tooth sprocket. You can go up one tooth on the front or go down 3 teeth on the rear. It will lower the rpms but no gain in speed.

[ProDigit]

Originally Posted by JerryHawk250

Won't work on the KPX. The KPX uses a 520 chain and sprockets. Not enough clearance for a 17 tooth sprocket. You can go up one tooth on the front or go down 3 teeth on the rear. It will lower the rpms but no gain in speed.

That would be with a 428 chain. I'm sure there are ways to get a smaller 530 rear sprocket on AliExpress, to get a similar gear ratio.

[nogreaterlove]

GPS check today. 20-50 mph is consistently showing 4 mph over actual speed. Above 50 mph it is showing 5 mph above actual speed. Actual GPS top speed today was 69 mph. Speedo showed 74 mph. second fill-up was 67 miles per gallon.

So 50 mph equals 46 mph
55 mph equals 50 mph
74 mph equals 69 mph

[JerryHawk250]

Originally Posted by nogreaterlove

GPS check today. 20-50 mph is consistently showing 4 mph over actual speed. Above 50 mph it is showing 5 mph above actual speed. Actual GPS top speed today was 69 mph. Speedo showed 74 mph. second fill-up was 67 miles per gallon.

So 50 mph equals 46 mph
55 mph equals 50 mph
74 mph equals 69 mph

Mine was the same. I installed the SpeedoDRD speedometer calibrator. Now it's dead on. Max gps speed was 74 mph.