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Old 06-24-2014, 09:30 PM   #135 (permalink)
Changfa diesel + Suzuki
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Join Date: Jul 2012
Location: Northern, NY
Posts: 527

Centurion - '74 FIAT X1/9 Centurion Full Race DNA
Last 3: 143.5 mpg (US)
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Originally Posted by sendler View Post
It makes sense if you think about it. Added mass improves the effectiveness of Engine Off Coasting with Pulse and Glide. And really only hurts fuel economy if you touch the brakes. Which we almost never do in competition. The increased rolling resistance is negligible and if the mass is gained as the result of an aero mod, it will be a big net improvement. I read a lot of comments about expensive techniques to reduce the weight of a vehicle as a means of improving the FE such as changing the lead battery for a lithium. Complete waste of money. FE only cares about the mass of the vehicle when you step on the brakes. Or if you are scrubbing the tires through the bottom of turn one.
I hear what you are saying however, you will never see a triathlete weigh down a bike or its wheels. Every acceleration and uphill chews up watts - even more if there's more weight do deal with. When you actually have to pedal a bike over long distances, you learn real quick what takes more energy and what takes less energy. Bikes, cars, cycles, it's all about energy used whether expressed in watts, hp, whatever. And, the rule of thumb is you will never gain on a downhill what you will lose on an uphill. Lightweight is where it's at. If the weight was in the form of aerodynamics - such as fairings for example - the weight may then be an asset since aero is a big deal (and rightfully so, ecomodder seems to be all about aero.) If weight works in your particular case that is excellent. I wouldn't dream of weighting down the Centurion - or for that matter the Changzuki. In real world driving conditions, if I fairing'ed the Changzuki and kept it lighter than your weighted bike, our mpgs would be miles apart I do believe...
Just for laughs, take this to the extreme - your bike with 3 extra large riders dangling off it at the GGP, and a clone of your bike with just you... Now think of all the corners, uphills, downhills, other traffic, etc that are on that track... I know which one I'd take if I were looking for high mpg. Just my opinion though...
And lithium batteries, well - the Aurora project would cave in with the weight of comparable AH lead acid batteries.. I cannot imagine tackling an uphill with them...

Last edited by changzuki; 08-04-2018 at 11:18 PM..
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