rpenmanparker 

So right! OP suggests that unloading the rear wheel reduces rolling resistance on that wheel and makes it easier to propel the bike forward since that is where the drive action occurs. But all the various forms of resistance at both wheels slows down the bike. Just apply the front brakes if you don't believe it. He is just transferring the rolling resistance to the front.

roadrecumbent

O.K., Got an SRM power meter crank and SRM Powercontrol V and Here's the results. The Chopper climbs faster than my Cannondale. Uses more power to do so, but gets to the top a little faster. Proves nothing maybe, it could mean it's easier to get up the hill, so I get done faster.
Got both bikes to 19 lbs. (With the HED wheels on both bikes) by removing the rear seat and seatpost from the chopper. Made shure seats were at the same height, and distance behind the crank. 105 psi in the tires. I tested on completely breezeless nights, on a hill next to my house. The same 10 degree hill that inspired this test. Steep hill, .16km / 175 yards long. 9 runs on each bike in 9th gear. Average time for the chopper- 57.7 seconds. Average for the Cannondale - 60 seconds ... Power average for the chopper- 48.3 watts, 12.7 kj. Power average for the Cannondale- 46.76 watts, 12.45 kj.
In conclusion, If I was riding the Tour de France, and came to the Alpe d'Huez, the chop would be my choice to get to the top the fastest.
Any questions?

Brian Ratliff

Surprise! 3% less power for the Cannondale leads to it getting up to the top of the hill 3% slower. Yay physics!

roadrecumbent

I expected to see less power used on the chopper, but I CAN use more and go up the hill faster because the lighter rear wheel is easier to turn, I'm thinkin'. I wanted to go up in 10th but the old Cannondale's derailieur kept me in 9th, so I kind of hit the wall on the Cannondale before I did on the chop. I used 9th gear on both bikes.

Brian Ratliff

relevant.

Long Tom

You've made Newton proud.

catonec 

Im still not buying one of those goofy things.

roadrecumbent

yes you are. Wait till you see the new handlebars, ect.

catonec 

cant wait.

roadrecumbent

Newtons laws are preserved.
How could my bike possibly "outclimb" another bike, get to the top of the hill faster without using more energy. If this lighter rear wheel design gets you to the top of a hill faster, it also has to use more energy.
Of course there could be human error, ... more testing is needed, I'll do some more tests for you guys, but I felt pretty good about the data.

pdedes

I'd like you to repeat the test on a climb of 3km or better.

Homebrew01

40+ watts ?? That is barely enough power to move on a flat road. Typo ??

Rather than try to reinvent science, I think you would be better of marketing the bike as unique, cool, different, whatever. Otherwise you will end up like that Z-Torque guy, making something different looking while trying to "prove" it is better.

roadwarrior

Kinda like there are no fast bikes, only fast bike riders.

Blue Belly

What does it matter how it climbs? With that front geometry it'll not corner well on a descent.

SpeshulEd 

Of course there's human error. You invented a bike that you want to prove can outclimb a normal bike. Unless an uninvolved third party is doing the testing, the results will always be skewed in the favor you're trying to prove.

ill.clyde

Excellent thread ... please do continue.

Fiery

False. If the wheel was "easier to turn", you would move at a greater speed under the same power.

False again. If your bike was, for example, actually, physically lighter, it would climb faster while using the same energy.

The data is pretty good. It conclusively proves you like to push a bit more on your contraption than on a standard bicycle. This means you have more fun riding it so that's good.

Brian Ratliff

Isn't this what you are trying to show? You could show that your body is more efficient on the new design (this is possible, recumbent designs definitely put the body in a different position relative to a road bike), but you didn't take the right data. Everyone knows that to push a bike weighing X pounds up Y hill in Z minutes, you'll need some fixed amount of power. What is more interesting is if you can show that your body is wasting less energy producing that power.

NeilMyers

Excellent analysis. This leads to a question I have always had. When considering weight, is there any difference between the weight of the bike versus the weight of the rider, all other things being equal?

In other words, if Rider A is 190 lbs with a 25 lb bike and Rider B is 198 lbs with a 17 lb bike they both have a total weight of 215 lbs. Does rider B (the heavier rider with the lighter bike) have an advantage (or disadvantage) over rider A, assuming they have the same ability to general power? Or is a pound a pound?

MegaTom

There's something to be said about rotating weight at the wheels, but otherwise a pound is a pound. Or a kilo is a kilo if you swing that way.

RPK79

The power output would have to be the same on both rides or your results are skewed. Have the Mythbusters build you a pedaling rig.

NeilMyers

Thanks. Confirms my suspicion that the cheapest way to better performance is to cut out calories and train more. Darn. It is so much easier to buy a lighter bike!

banerjek

Despite being light, that bike looks like it would weigh a ton. Which makes it seem to move much more easily than people would think. Mystery solved...

nhluhr

Oh there's plenty of that.

By the way, your SRM is broken.

roadrecumbent

My first chopper only had a back seat. It was a horrible, horrible climber. With a front seat there's a change in geometry, and now it climbs at least as good as a road bike. Biasing the weight to the front wheel is another change in geometry, why shouldn't that change performance as well?
I've switched to Sram XO 10 speed gripshifts for the new handlebars, this ment I had to buy new derallieurs (I got some nice used Red on ebay) So I put the old Dura Ace on my Cannondale yesterday and will do 10th gear trials now.
If I'm still going up the hill faster, I'm going to go 15 miles to Stanford University and talk to the engineering department, and see what they think. I hope they don't just argue about it. I will get back to you.