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Yesterday, my home town is pouring rain and i tried my bike to my limit. although my bike only just travel for 100 km (62 miles), but i risk it and tried as fast as i could. And it reach 132 km/h (82 Mph) at raining condition, at nite, on a semi freeway. Perhaps because it still new or i'm just afraid with the condition, it's easy to reach 120 km/h (74 mph) but then it get slow to reach 130 km/h (82 mph).
Could it be because the euro 2 type exhaust, or any other factor? i don't really know.
I got nearly the same behaviour, but I guess that's because I live at 2600 meters over the sea level. Where do you live bro? I guess I'll never be any higher than 130kmh at my hometown without any modification.

It accelerates smoothly till 120kmh and then it takes forever to go any further. I used to have a Hyosung 250 and it reaches 130kmh with no effort.
 

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Hm. I have to wonder... rider weight, terrain, air density (both for aerodynamics and feeding the hungry engine), etc...

I held over 90 most of the way into the office this morning.
 

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Your bike is clearly not running right.
I have the same speed issues he does. It plateaus at 79 MPH, takes a second or two, then rolls over to 80. WOT. Not kidding. I don't know how you guys get anywhere near 90 MPH unless your rolling out 4th and 5th gear really far. I've read reviews of the bike that say it's good for about 80, so I've just started accepting it as a reality. Otherwise, that's a pretty significant variation in speed for a brand new bike. Now keep in mind I'm talking about 6th gear roll on, which stops climbing just about at peak power. My V-twin I had before this, you could lay into it in top gear at 35 MPH and it would climb all the way to top speed through its own muscle. No special techniques needed. At 23rwhp, this one seemingly won't do that.
 

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I don't know how you guys get anywhere near 90 MPH unless your rolling out 4th and 5th gear really far.

[cut]

Now keep in mind I'm talking about 6th gear roll on, which stops climbing just about at peak power.
Mechanical advantage is exactly that... advantage. 6th gear is overdrive, it's actually a disadvantage, the transmission input shaft is turning slower than the output shaft.

Now, theoretically, it should not matter which gear you "roll on" (wasn't that a type of deodorant that became less popular years ago? LOL) it should still eventually get there...

But... (posting this again)


This is the chart (stock gearing assumed) I made a few days ago showing what the torque drop/advantage is for each upshift, if the shift is made at a certain RPM.

Theoretically, if you take this bike all the way to redline, you gain a large torque advantage, but that's because the torque drops off rather rapidly at the higher RPM, and the ratios throw you back into the nice flat "sweet spot" of the torque band.

If you shift out most every gear at 8000+ RPM, you gain an advantage in torque (rather than losing torque in the shift).

The bike may only aspire to be a true sport bike, but the engine is designed to be taken up to and kept within the power band.

But, every bike, every rider is different. Depending on your "profile", you'll create more drag. Depending on your weight, it will be harder or easier to pull you up to speed. Depending on your tire inflation/choice, you'll have different rolling resistance. Depending on how well your machine was broken in (that is, how well the piston rings sealed) will determine how much of the compression stroke and power stroke stay confined within the cylinder while the valves are closed. Likewise, any slight tightness to the valve clearances (that is to say, the valves to not close completely) will also rob you of power. Too much oil, windage losses come into play. How well lubed and adjusted your chain is, this also comes into play.

This is why racing is technical... and why I love 250's... every minor thing can be a major setback down the road, you have to give the bike TLC in maintenance, and treat it the way it needs to be treated in order to squeeze every last ounce of power out of it for the advantage.
 

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TX_Dj, 1st let me say this diagram is very interesting. This reminds me of a conversation between Allen and I on page 3 of the Shift Point: Peak HP VS Redline thread. While the graph may be true for engine torque, is that taking into account the gear ratio as a multiplier? If not, it may in fact always be better to shift just before redline. I don't shift that high, so it never gets pulled up to that speed before being dumped into 6th, which won't go past 8,400 RPM's on its own in my case, and would explain what's going on with those of us who top in the low 80's.
 

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I have the same speed issues he does. It plateaus at 79 MPH, takes a second or two, then rolls over to 80. WOT.
If you tuck so that you are looking just over the top of the windscreen with your elbows hugging the tank, the CBR250R will do 90 mph easy. Almost any rider. Weight doesn't matter much for top speed runs. Only frontal area. Skinny guys under 5'10 can get lower behind the screen for 93 mph. My longer gearing takes me to 86 mph in 4th at redline, 93 in 5th and 96 in 6th with a good tuck. Flat road, no wind.
 

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If you tuck so that you are looking just over the top of the windscreen with your elbows hugging the tank, the CBR250R will do 90 mph easy. Almost any rider. Weight doesn't matter much for top speed runs. Only frontal area. Skinny guys under 5'10 can get lower behind the screen for 93 mph. My longer gearing takes me to 86 mph in 4th at redline, 93 in 5th and 96 in 6th with a good tuck. Flat road, no wind.
So you're talking redlining 4th and 5th to hit top speed? So the gearing is actually creating the rear wheel torque as opposed to the engine power fighting top gear. That makes sense then. Hm. This is the 1st bike I've personally ridden where breaking 80 MPH took a specific technique. It's not that I need to break 80, it's that we have a 70 MPH highway here, and there's not a lot of breathing room when the other cars start cruising around 75. For sustained speeds, I'm feeling almost maxed out at that point if there's an upward slope in a stretch of road. I'd have to drop a gear in that condition, which is kind of unnerving when I'm already running that close to peak power. Luckily traffic doesn't go any faster than that.
 

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The only technique you need to break 90 is to tuck. It's all about aerodynamics. I can roll on in 6th from 70 mph and get to the same top speed as if I redline 4th first along the way. It just takes longer to get there.
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So you're talking redlining 4th and 5th to hit top speed? So the gearing is actually creating the rear wheel torque as opposed to the engine power fighting top gear. That makes sense then. Hm. This is the 1st bike I've personally ridden where breaking 80 MPH took a specific technique. It's not that I need to break 80, it's that we have a 70 MPH highway here, and there's not a lot of breathing room when the other cars start cruising around 75. For sustained speeds, I'm feeling almost maxed out at that point if there's an upward slope in a stretch of road. I'd have to drop a gear in that condition, which is kind of unnerving when I'm already running that close to peak power. Luckily traffic doesn't go any faster than that.
 

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While riding to lake erie last weekend on a on a lonely country road, not in a tuck, i pinned the throttle back and topped out at about 76mph..im 5'9" 200lbs. riding into a 5-10mph head wind..thats the fastest ive ever gone on two wheels..
 

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That working with the bike technique, tucking behind the windscreen, and shifting near redline is what makes the Honda CBR250R so much fun to ride. You can give it all the beans she has, and feel like an virtual MotoGP3 rider :cool: while on the freeway flowing with faster moving traffic. No other bike would allow you to do that without flagrantly speeding :D :D
 

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That working with the bike technique, tucking behind the windscreen, and shifting near redline is what makes the Honda CBR250R so much fun to ride. You can give it all the beans she has, and feel like an virtual MotoGP3 rider :cool: while on the freeway flowing with faster moving traffic. No other bike would allow you to do that without flagrantly speeding :D :D
And this right here is why I love this bike regardless. :cool: Way to turn a negative into a positive.
 

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Got to 84 today without much shifting strategy. Once I tucked at around 70 it got to 80 pretty quick, but it seemed to have trouble getting above 84 before I had to slow for my turn.
 

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Got to 84 today without much shifting strategy. Once I tucked at around 70 it got to 80 pretty quick, but it seemed to have trouble getting above 84 before I had to slow for my turn.
Yes, quite a number of factors can hold you back from going any faster. Are you truly on the flat, or a slight incline or is it slightly downhill? Are you truly riding w/o wind, or a slight headwind or is there a tailwind? What is the quality of the tuck, how much oil, what tire inflation, etc etc etc...

Every tiny, miniscule thing that any rider with more power rarely really worries about, all these would hinder you from hitting a higher top speed.

That said, of course, 84 is fast enough to get you a speeding ticket. ;)
 

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i finally decided to crack it a little more the other day on the way home. flat ground 10km/h wind against me, i hit 155km/h and thats when i let off. it still had some more but i didnt really wanna push it much more. i think thats roughly 95 mph. this is why i dont understand the people saying they can only got 125-130. i will regularly cruise side roads at these speeds. and the bike isnt over working its self.
 
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