will rider weight effect top speed

[bigsled]

i've been searching alittle. how many mph ? anybody wanna throw in your thoughts :cool: :: some of the threads here claim more hp if you weigh less. so wouldnt that increase your top speed :confused: thanks:D

[54warrior]

Originally posted by bigsled
i've been searching alittle. how many mph ? anybody wanna throw in your thoughts :cool: :: some of the threads here claim more hp if you weigh less. so wouldnt that increase your top speed :confused: thanks:D

First of all, the weight of the rider has absolutely NO effect on the hp of the motor. NONE, ZIP, ZILCH, ZERO. The engine has the same amount of horsepower regardless of who is riding it and what their weight is.

Second, stop for a second and think about your question: will rider weight effect top speed? the answer is obviously YES. However, in my opinion, a 10-20# difference doesn't mean diddly doo. I, for example am 6'7", 285#. If my neighbor who is 5'4", 145# climbs on the same exact machine, I guarantee that the difference will be noticeable. I would wager that it's not more than 5mph though.

[wilkin250r]

Let's not confuse our apples and our oranges, here.

The main factors in ACCELERATION are power and weight. Less weight results in faster acceleration. This would certainly reduce your lap times around a track.

However, top speed is often a function of gearing, rev limit, and wind resistance. More power can overcome more wind resistance, so power can definitely affect top speed. But power/weight ratio has very little to do with top speed.

[bigsled]

Originally posted by 54warrior
First of all, the weight of the rider has absolutely NO effect on the hp of the motor. NONE, ZIP, ZILCH, ZERO. The engine has the same amount of horsepower regardless of who is riding it and what their weight is.

Second, stop for a second and think about your question: will rider weight effect top speed? the answer is obviously YES. However, in my opinion, a 10-20# difference doesn't mean diddly doo. I, for example am 6'7", 285#. If my neighbor who is 5'4", 145# climbs on the same exact machine, I guarantee that the difference will be noticeable. I would wager that it's not more than 5mph though.

yea , i'm 275 and 6' 4" and i was just wondering how much top speed i would gain by being , say, 50 lbs lighter :D

[GPracer2500]

Like wilkin said, weight has next to nothing to do with top speed.

The barriers to faster top speeds are drag related. Wind resistance is by far the largest type of drag that must be overcome. The rolling resistance of the tires is also a factor and that can be affected by weight. So weight could indirectly affect on top speed. But that can largely be compensated for by increasing tire air pressure to match the weight. If you weigh 300lbs then you're gonna want a few more psi in the tires vs. a 100lb'er.

If you're talking about a dramatic difference in weight (I wouldn't consider 50lbs dramatic in this context), then just make sure your tire pressure is appropriate. Given that, it's ok to ignore the affect weight has on tire rolling resistance because tire rolling resistance is grossly overshadowed by wind resistence. I don't know how the numbers would work out exactly, but I'd guess at an ATV's top speed the difference in rolling resistence created by +/- 50lbs would be a small fraction of 1% of the total drag.

Weight could affect top speed in another indirect way. If the change in weight was accompanied by a change in frontal area (i.e. bigger weight = bigger size) then you might be able to measure a difference in top speed if the change was large enough. But really, weight wouldn't be the factor at play--wind drag would be.

Just do like this guy.... ;)

http://patentpending.blogs.com/photos/uncategorized/capture1014200482331_am.jpg
[1948, Vincent Black Lightning on the Bonneville Salt Flats setting a motorcycle land speed record at 150mph]

[400exrider707]

Originally posted by GPracer2500


Just do like this guy.... ;)




ahahahaha, thanks I needed that, work sucks! hahahahahah

[Honda#4]

I'd hate for that guy to fall off that bike like that.