Recent content by wturber

Cite your source please. But even if you are correct, you need to discount the MPGe by at least 40% using your own figures. Well, that's a statement you make. But you haven't shown the evidence. In fact, the evidence you have shown suggests less than 2x as efficient using your apples to apples...

MPGe does not include conversion and transmission losses. If your estimates of such losses you gave earlier are correct, then the advantage is about 1/2 of 3.5 or 1.75 times as efficient. That also seems to roughly jibe with the energy cost to the user. So maybe regulatory and subsidy issues add...

I would classify the car as ICE or EV based on where it gets its energy. If it gets it from the pump like a Prius does, it is an ICE. If it gets it from a charging station it is an EV. The lines get blurred with the plug-in hybrids that source their energy from external electrical sources. I...

One problem with cost comparisons is that you don't know the degree of subsidy or tax at the various stages of energy production. So it is a perfectly practical way to be guided on what to purchase (tho estimating future trends puts some wrinkles in that), but it is only somewhat related to...

I suggest scanning the file with different tools. I'd also check with whomever it is that publishes the file and get an explanation from them. Given how uncommon and niche the file you are talkin about is, I'd bet this is a false positive. That said, it is good to be careful.

Not free. Just previously paid for. Also, that person doesn't have to be overweight. Even people with "normal" BMIs can have a lot of fat on board ready to be burned. For instance one calculator give a person at my height of 5'10" a range of 130-170 lbs as being normal. And as it is, I...

True. But that means the person had to previously consume the food and calories in order to have the fat on hand (or belly) to burn. So the points @neptronix made about calorie consumption, energy efficiency and cost of calories remain.

Many good points, but I get my extra calories on regular bike rides mostly from relatively inexpensive carbohydrate foods. I don't spend anywhere near $4 for my extra 1000-2000 calories - mostly generic fig bars and sugar added to tea. I also consider that a certain degree of physical exercise...

I posted more info about this bike a few months back when I completed it. Figured I'd add it to this before and after build for grins. Too bad I don't have a photo of the Trek 820 by itself. The nice folks at xtracycle dug up as many original decals as they could find and that helped me with...

I'm running 3.15. I believe that is the latest stable version, but I'm not certain. It is certainly working fine for me though. But if you run the Grin software, that should tell you for certain. The Grin page says 3.14. But that page hasn't been updated since March of 2023. So I think it is...

Whatever spins yer spurs I guess. But I don't race bicycles. I ride them for pleasure, utility and for exercise and fitness. So small gains in aerodynamics don't matter much to me. I'm riding an old Trek 770 road bike. It has a moderately modern 9 speed rear wheel that just barely works with the...

Right. That's surely the key reason that the benefit seems to come from having the top portion of the wheel covered. Drag increasing with the square (or is it cube?) of speed, 2x can really matter.

Nothing new here really. https://bikerumor.com/null-winds-aerodefender-carbon-aero-fenders-slice-headwinds-faster-than-aero-wheels/ Here's an abstract from the technical paper. There was apparently no actual physical test. This was all done using computer modeling...

The guy who made the video requested and received a data sheet on them. That sheet said that the cells could be recharged not less than 300 times. I've seen other 20400 cells claiming 500 cycles. I wonder whether all of the batteries used were from the same maker or not. Seems unlikely that...

Wildly unsafe? That seems a bit harsh. I'm pretty sure that the cells he's using don't have the safety mechanisms common with modern 18650 cells. So I certainly don't think this is a "safe" implementation. But he at least did a decent job of building the battery with an appropriate BMS...