Apparent proof that tire weight affects Dynojet results
Tourer
Joined: Dec 2005
Posts: 417
Likes: 3
From: CT
I don't see the point in this thread.
Of course the results are correct and you will actually accelerate faster on the road (albeit very , very slightly) because the engine is accelerating the lighter tire faster and you will accelerate faster, so in reality, the dyno is correct stating that you have more horsepower.
Fat tires cost performance.
The point again?
Of course the results are correct and you will actually accelerate faster on the road (albeit very , very slightly) because the engine is accelerating the lighter tire faster and you will accelerate faster, so in reality, the dyno is correct stating that you have more horsepower.
Fat tires cost performance.
The point again?
Thread Starter
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Stellar HDF Member
Joined: Feb 2014
Posts: 2,710
Likes: 529
From: Lethbridge, Alberta Canada
You're right. I thought I was passing on useful-to-know info, but apparently I wasted my time. I think in the future, I won't bother. Too much work and too much criticism. 
Jim G
Jim G
Outstanding HDF Member
Joined: Aug 2012
Posts: 3,217
Likes: 90
From: Detroit
Why are people being so hard on Jim?
Some of us hardcore motorheads already knew what he is stressting, but I'll bet a lot of readers didn't.
When you accelerate a tire/wheel, it saps a lot more power than most other weight in the vehicle. There's the weight of the tire/wheel as part of the total vehicle weight, but there's an additional component of the power required to increase the rotational speed of the wheel and tire.
Some of us hardcore motorheads already knew what he is stressting, but I'll bet a lot of readers didn't.
When you accelerate a tire/wheel, it saps a lot more power than most other weight in the vehicle. There's the weight of the tire/wheel as part of the total vehicle weight, but there's an additional component of the power required to increase the rotational speed of the wheel and tire.
Tourer
Joined: Sep 2014
Posts: 449
Likes: 3
From: England
Interesting read, Jim. I've been into drag racing for years and have spent a lot of time, money and research to put more power to the ground in my mustang. It's proven that lighter components in the drivetrain reduces drivetrain loss by providing a mechanical advantage to transfer more power to the wheels (or wheel for a motorcycle).
I'm not sure why there is such harsh critiques. The original post showed some numbers based off of two dyno sessions using two different tires...there may be some other factors involved but the simplicity of mechanical advantage makes perfect sense to me.
I'm not sure why there is such harsh critiques. The original post showed some numbers based off of two dyno sessions using two different tires...there may be some other factors involved but the simplicity of mechanical advantage makes perfect sense to me.
Thread Starter
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Stellar HDF Member
Joined: Feb 2014
Posts: 2,710
Likes: 529
From: Lethbridge, Alberta Canada
Jim G
Road Warrior
Joined: Jun 2010
Posts: 1,368
Likes: 27
From: Australia
Hi,
Good, i just about to buy some new boots so i wait for your report
Interested in ones with a good gripping sole
Thanks
Mirrmu
Good, i just about to buy some new boots so i wait for your report
Interested in ones with a good gripping sole
Thanks
Mirrmu
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Road Warrior
Joined: Oct 2012
Posts: 1,358
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From: Dallas
Nobody is being hard on him. Everyone is simply stating what has been known since the invention of the wheel. Less rotating mass equals more power to the ground. Jim made it sound like he had just discovered this.
Thread Starter
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Stellar HDF Member
Joined: Feb 2014
Posts: 2,710
Likes: 529
From: Lethbridge, Alberta Canada
In other words, if 2 bikes each with the exact same engine show different power on the dyno it is NOT reliably because one engine builder assembled the engine better; one bikeways simply have a heavier wheel.
Jim G