ItIsWhatItIs
Banned
Fixed
GS500 max speed in top gear?
- Thread starter haisam10
- Start date
Fixed
spaceboy
Well-known member
Glad to see you're enjoying the bike, Haisam. If you want it to really move, you have to downshift.
The front sprocket on the bike is -1. The extra one I included is -2.
Edit: Going -1 on the GS actually increases the top speed, because the power curve drops off at the top end.
The front sprocket on the bike is -1. The extra one I included is -2.
Edit: Going -1 on the GS actually increases the top speed, because the power curve drops off at the top end.
mma01
Well-known member
The 500lb rider would have a lower top speed than the 100 lb rider simply because the former's body shape will result in a less efficient aerodynamic package (as I pointed out in the first post), not because of weight alone.
Assuming that a 200 lb rider and a 150 lb rider present roughly the same level of aerodyanmic drag, the major difference will be how quickly they reach terminal velocity - the difference in top speed will be miniscule!!!!
http://www.physforum.com/index.php?showtopic=14909
Sundie
Well-known member
Alert! Someone on the internet is *wrong!*
Anyway. since no one has done it yet:
front sprocket:
smaller (less teeth) = faster acceleration/lower top speed
larger (more teeth) = slower acceleration/higher top speed (although there is a practical limit to "higher top speed" because you need to over come more and more wind resistance)
rear sprocket:
smaller (less teeth) = slower acceleration/higher top speed (same caveats)
larger (more teeth) = faster acceleration/lower top speed
And weight has nothing to do with top speed on a flat and level surface, given the same profile, which (as someone pointed out above, unless you're Fat Bastard or carrying a sail) is almost identical for every rider if they're tucking in.
Anyway. since no one has done it yet:
front sprocket:
smaller (less teeth) = faster acceleration/lower top speed
larger (more teeth) = slower acceleration/higher top speed (although there is a practical limit to "higher top speed" because you need to over come more and more wind resistance)
rear sprocket:
smaller (less teeth) = slower acceleration/higher top speed (same caveats)
larger (more teeth) = faster acceleration/lower top speed
And weight has nothing to do with top speed on a flat and level surface, given the same profile, which (as someone pointed out above, unless you're Fat Bastard or carrying a sail) is almost identical for every rider if they're tucking in.
That's... Interesting. I can almost see how that would work... But i can't think that 1 tooth has that big of an effect? I mean... you'll reach your previous top speed later in the curve, which is where you're saying power drops off...?
Sundie
Well-known member
there's a flaw in your argument. The 500 lb rider could be a very short compact person in race leathers, and the 100 lb rider could be a beanpole with a penchant for loose clothing flapping around.
A more reasonable discussion would be a 120lb rider vs a 120lb rider with 380lbs of weights riding pillion. Same top speed.
mma01
Well-known member
You are just being picky for the sake of it. You know what point I was getting at (the impact of aero vs weight).
Sundie
Well-known member
Yes, but you were being ludicrous by assuming a 500lb rider in the first place. But you had to be, to link weight and aerodynamics in the first place.
And, point in fact, differences in rider weights between 120 and 300 (reasonable upper and lower limits) present very little drag co-efficient difference, given that both would likely be tucked in.
mma01
Well-known member
You may have missed it, but I was merely responding the other poster who raised the "ludicrous" situation of the the 500 lb rider vs the 100 lb rider (see post #34).
If you want to talk about ludicrous assumptions, how about the loose clothing assumption in your post? Why stop there? Why not assume the skinny guy is wearing a deployed parachute too lol.
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Sundie
Well-known member
And you went with it, rather than arguing against it. *shrug* I was pointing out the flaw in your test. then offered a much more accurate test. Then asserted that the drag co-efficient difference between a more reasonable comparison (120 vs 300) would be negligible.
Thus, my point. You can either go silly with assumptions, or try to craft a realistic comparison with limited variables.
Sundie
Well-known member
There there. <pat pat pat> it will be all right.
Wow, you do of course realize that absolutely NO ONE in this thread has ever mentioned that weight will not affect acceleration. You are completely mistaken on your understanding of how things work (specifically top speed & weight). Also, you should know, it's quite common to use an absolutely absurd quote as a signature tag line. What toysareforboys did is no different than what I have in my signature, only this time, it's your crazy post being used. My suggestion, stop posting when drunk, or when you truly don't understand the topic at hand.
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ItIsWhatItIs
Banned
Weight effects power. Power is required to get to top speed. I suggest you read all posts and quoting and then cite a correction instead of talking out of your ***. Perhaps I am not 100% accurate. Where I am not accurate is an opportunity for someone to contribute a correction.
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To get to the top speed, the bike needs to accelerate. The acceleration will be lower with higher weight, and higher with lower weight. As a matter of fact, the power may be the same, and in case of WOT it will likely be the same---the engine will be pushing as hard as it can.
In practice, the rider may cause the bike to be unable to reach the predicted top speed, but that has more to do with air resistance, which in turn has more to do with the shape of the rider, not necessarily the mass. Also, if the acceleration is really low, the bike may run out of gas before reaching the top speed.
At high speeds air resistance is so significant that it can no longer be ignored in any serious models. The problem however, is that it's not correlated with mass in any obvious way. The wind will have a harder time slowing down a heavy object, just as you will have harder time getting it to accelerate. In general, there is no easy way to put the wind resistance into the equation and there will be a lot more parameters than just mass.
ItIsWhatItIs
Banned
The op was griping about his bike. Touches on his weight and there is no power left for him to accelerate after 120. His solution is to get a bigger bike. Perhaps a better solution and a lower cost solution is to adjust his sprockets at the expense of Top end speed of his bike. Did a quick google. There are claims of 100 to 115 mph for the gs500. 120 km is about 65 mph. Playing with the sprockets to bring his top speed to perhaps 80 mph will give him the acceleration after 120 kph he is looking for. However, he will be cruising at a higher RPM and he will be sacrificing fuel economy. The GS500 has a good reputation for performance and reliability. The op should do what he can to customize his bike before abondoning his bike for another.
Friction in the wheels bearings, and energy that goes to deforming the tire is negligible at that speed compared to air resistance.
GS500 should feel good around 120km/h, you should have a decent amount of power left. It's no torque monster as far as bikes go, but it will still out accelerate most commuter cars at 120km/h. Something may be wrong with your engine.
edit: wow old thread and there's a second page.
Kokla
Well-known member
That's just terrible trauling.
Sorry for bumping an old post, but man dem chich.. these things are funny.
