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Discussion Starter #1
I'm putting a question out there just for the fun of it. We can call it the 10% solution.

We have bandied about the value of titanium hardware and lithium batteries and I could add carbon fiber parts to that list also. So my question is : If there was no cost involved and you will not weaken anything but you can choose only one option would you ? Add 10% more horsepower, have the machine 10% more aerodynamic or subtract 10% of the total weight.

This was a question my engineering professor posed to the class on a mid-term. In the end he graded each of us based not only on if we were correct in our choice but how we arrived at that choice.

Cheers
 

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I ride trials bikes, so aerodynamics mean squat
& 10% less weight would only be about 16 pounds, that ain't gonna cut it on its own,
give me the horsepower, it might be fun.
 

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Discussion Starter #4
LOL can't help ya Mate Popeye would suggest......................well never mind can't help you
 

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If I was 10% stronger I could get more performance out of the bikes I have now. Tell your teacher that one.
 

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Discussion Starter #6
He would most likely have agreed with you. Only time I ever saw him surprised was when we watched a Peterbuild wind tunnel test of a cab-over truck. He stood there with his mouth open when we found out that the mirrors accounted for 11% of the total drag on the truck. As far as your proposition he would no doubt allude to strength (or lack there of) would result in not having optimum body position and proper lever angle but I'm sure he would have agreed. He once told a student that weight transfer was, in his case more about transferring his weight away from the dinner table rather than towards it . So he did include the human factor.
 

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I just need to ride more, but it's difficult unless I have riding partners I can't do much solo. My dog is pretty useless company if I crash, all he wants to do is bark at me.

Knees are the worst thing, if I can't squat and jump, it's very hard to make the bike squat and jump. I'm having to find ways to deal with that one, best I found yet is to come into a zap or a splat with my knees in a deep bend and then just straighten them at the right moment, seems to help but now I need to figure out how to do a double or triple step.


,,, and probably nobody on here has a clue what I'm talking about :alien:
 

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Discussion Starter #8
I totally understand your knee problems. A year ago a lady pulled out from a side street and I was ALMOST able to stop. Just before impact I stood up so I'd fly rather than die but it didn't save the knees.

At least I've had plenty of time to putter in my shop and work on the race bikes. Things do take a wee bit longer but they're getting done. Cheers
 

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10% more power or 10% less weight give the same improvement in power to weight ratio but extra power doesn't help handling. It would make a little difference to top speed but not to acceleration compared to weight reduction, so not the HP thing. Force=Mass x acceleration as I recall.

10% better aerodynamics is proportionately more effective than 10% hp in terms of top speed because that's a square situation, but it really only makes a difference on long fast tracks with lots of high speed, so let's not do that in isolation.

10% less weight improves acceleration out of corners and will also improve handling and therefore potentially speed through corners. Better acceleration out of every corner is good and would achieve higher top speed before every corner, though not necessarily as high as better aerodynamics on a long enough straight. But that improved acceleration and higher cornering speed would be more beneficial on all tracks with enough corners.

Overall 10% decrease in weight probably results in the best lap times on most circuits IMHO and no I am not going to actually calculate the differences for any circuit. But the best result has to come from reducing weight, improving HP and improving aerodynamics as well.
 

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Discussion Starter #10
10% more power or 10% less weight give the same improvement in power to weight ratio but extra power doesn't help handling. It would make a little difference to top speed but not to acceleration compared to weight reduction, so not the HP thing. Force=Mass x acceleration as I recall.

10% better aerodynamics is proportionately more effective than 10% hp in terms of top speed because that's a square situation, but it really only makes a difference on long fast tracks with lots of high speed, so let's not do that in isolation.

10% less weight improves acceleration out of corners and will also improve handling and therefore potentially speed through corners. Better acceleration out of every corner is good and would achieve higher top speed before every corner, though not necessarily as high as better aerodynamics on a long enough straight. But that improved acceleration and higher cornering speed would be more beneficial on all tracks with enough corners.

Overall 10% decrease in weight probably results in the best lap times on most circuits IMHO and no I am not going to actually calculate the differences for any circuit. But the best result has to come from reducing weight, improving HP and improving aerodynamics as well.
You could have been in that engineering class and you'd have gotten a fairly respectable mark. You did leave out two other benefits from reducing weight. More HP increases fuel consumption meaning you must carry more fuel and lessing weight decreases braking distance thus allowing effectively longer straights. Otherwise you were right on the money. One of that professor's other points about weight was that even if the rules dictate a minimum weight it would be to the engineer's advantage to make things as light as can be and then bring the weight up to the required by placing the ballast to a location of advantage like low center mass. You Teazer get an "A"
 

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Thanks for that Teazer. My guess was 10% less weight, but it was only based on a gut feeling I had. You were kind enough (and clever enough) to actually express in understandable English, why the weight option was the best. My feeling about the weight thing dates back to the 1960s when one of the Italian 250 singles ((Moto Guzzi, I think, but don’t quote me) was still more than competitive against Honda’s 250/4. To save weight, they didn’t even paint the frame.
 

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I cheated. I have a degree in mechanical engineering here somewhere. It doesn't get a lot of use though.
 

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Discussion Starter #13
LOL You think your engineering degree is not getting used. I was a Psychology major with a minor in History. I did a wee internship at a state hospital and that was enough. I went automobile racing because there I found the people with mental problems that I could relate to. Cheers....................OH ! and you still get your "A" reading books can't be a disqualifier.
 
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