I cannot increase speed over 120 km (74 miles)
 

Hi fellows. I have mondial rx3i evo (zongshen rx3 sold under this brand) in Turkey. My problem is i cannot exceed my speed over 120 km on the sixth gear! No problem up to 110 km speed per hr on the clock. But at most i have seen 120 km per hr on the sixth gear, and the rev will never exceed 7400 rpm.

Model of my zong is 2016. It has some differences than that of 2015 version sold in Turkey. For example, front wheel is 19" (18" for 2015) and the rear 17" (15" in 2015) in the 2016 version of our zong rx3.

I have this bike for more than one year and total km is over 10 k on the clock. Valve clearences checked and adjusted. No other problem. Normally i have expected 135 km per hr (84 miles per hr) speed but never got this so far.

What could be the reason? Any idea? Thanks fellows.

that's about right depending on what kind of weight you have on it. they just simply run out of power to push against wind and weight at some point. My hawk does the same thing, but at a lower speed.

Is the Turkish RX3 fuel injected? I don't own an RX3 so not exactly sure what top speed to expect. In my experience realistic top speed is at least 10kph less then advertised speed. Fuel injection adds a fair bit of power to the RX3 so if yours isn't fuel injected then that might account for the shortcoming.

Do you have any side luggage/boxes, ride with baggy clothes, or anything else that makes the bike less aerodynamic? Wind resistance kills top speed on small horsepower/torque vehicles

What is the tooth count of the front and rear sprocket? Might be topping out the speed due to improper gearing?

Is this 7400 rpm only in sixth gear or also in fourth and fifth?

Jay.

I just did a WFO test (loaded bike with Tourfella luggage), flat ground and minimal wind.....74 mph by my GPS. I suspect that's pretty normal for a 24 hp bike pushing a lot of air resistance.

Peter Y.

Thank you all for your replies. I compare my bike with other similar rx3 models sold in Turkey. Normally many other 2016 model RX3 bikes accelerates over 135 km per hour speed.

Yes i have side and top cases, but orhers also do.

My bike fuel injected, as others.

Gears, other than the sixth, can reach and surpass 9000 rpm.

My friend has the same bike, he has a weight over 120 kilos, at least 15 kilos more than me. He saw 135 km speed on the clock of his bike. Also, i watch many youtube videos on internet, in which RX3 bikes exceeded over the speed of 130 km per hr on the clock.

Perhaps the only difference between mine and my friend (and probably other) bikes is that i changed my rear tire with metzeller tourance, size of which is 130-80/17 (orginal tire 130-70/17). This gives me a 5 km per hr more speed on the clock at the same rpm.

The only thing i consider for this situation is that when my bike was new, i never exceded 6000 rpm on either gear. Do you think this may be the couse of this.

Thanks.

In 5th gear you should be able to pull redline easily.
In 6th gear at least within 500 rpms of redline.

This is under good conditions(flat road,no wind)

I'd try running one of your friends flat out and see how they compare. Also, sounds to me like it's just pushing as much wind as it can. We can't lose sight of the fact these are just 250's. Do you have different gearing than your friends?

Higher tire pressure will result in less rolling resistance, thus a possible higher top speed and better fuel mileage

http://worshippingchristian.org/imag...flated_ego.jpg

Just like the current resident.

@naci I am probably using the same bike as yours... and I was able to see 133kmh on bike only once in blue moon...

but please keep in mind my Odo meter always showed me speed of 135kmh, 140kmh, and some timmes 158kmh on 6th gear redline...

I released very soon it wasnt really 158kmh after all... as I have Suzuki-GS500 as well so I was well aware of 158~160kmh speeds...

so I did a GPS check and when showing 154kmh it was actually doing only 133kmh that day... so I can roughly and easily prdict that when I saw 158kmh on odo i was hardly doing a 135kmh or some where around it..

Bike needs a neat and paved road with no changes in altitude and quite a bit more then couple of kilometers to actually go red line in 6th gear .. rememebr you only have 24horses and you are pushing a vrey heavily loaded and a big eind signature bike on road...

same engine in a trail bike and it would take off like an f-16 :D ( referring to Kayo-6)

Same engine in RC3 and the claimed speed it above 140kmh.

Yeah, it's well known that the speedo is way off on the bike. I purchased and installed a SpeedoDRD to allow calibration of the speedometer. $70 USD and about 30 minutes to install.

Changing out the rear wheel shouldn't change the speedo readings as the speedo sensor is on the front wheel.