HNaTTY

One thing that always bothered me about airplanes is the energy used to take off. On aircraft carriers, they use a launch device, allowing the airplane to "push off" against the carrier. Compare this to airplanes taking off on land, they just nail the throttle and take off by pushing air...

A land-based launch system would have a lot of advantages; lower peak power would be needed from the motor and batteries, the engines could be made smaller, the energy used to take off doesn't have to be stored on the plane, everything gets lighter and more efficient.

My 1700x build for video processing has suffered major instabilities -- app crashes and BSODs -- memory corruption type errors. I went through 4 different types of DDR4 memory until I found some that works, even though it isn't on the ASUS's Qualified Vendors List. My advice is to make sure your RAM can do 15-15-15-36 timings (or better).

The filter checkboxes are a bit weird, for example elements (such as br and img) which are both self-closing and inline only show up if both self-closing and inline are selected, instead of one or the other. Also there are several elements such as li which are not categorized and show up even if no checkboxes are selected.

Publicly shaming Gigster like we're doing here should help.

To a large extent, my daily driving consists of going to the same 5-10 places. I'd like my car to watch me drive somewhere and then just do that, with minimal improvization. For example, in order to enter my driveway I have to swing wide into the oncoming lane to make the turn. When I drive to work I avoid the same potholes all the time. Pretty trivial to just record my driving once or twice, and replay that back with minimal improvisation.

Fair point. You don't measure fuel economy on cars by running them on an oval track with the accelerator pinned.

Oh yes, and nobody cared about the performance aftermarket (basically anything you do is going to violate emissions standards) until Harley started selling bikes already modified for "racing".

I dropped 20 lbs off a 330lb bike (and added about 5hp) by replacing the heavy dual exhaust with a single Ti/carbon pipe, and reprogramming the ECU. I'm sure the manufacturer would have loved to give me a 310lb bike that made more power if they could. (and before you ask, no it's not loud, I hate loud pipes)

Incidentally, the exhaust/ECU upgrade was done by the local shop when the bike was purchased new. Basically the same as what H-D was doing.

Anyway, what H-D got popped for is arguably less egregious than what VW was doing. They admit that the modified bikes bypass emissions requirements, whereas the unmodified VWs didn't meet the requirements and had to cheat to pass inspection.

One megahertz is more than enough. That's enough power to compare like three-thousand integer values per second, which is way more than a human can do. We've got these guys out there, and they've got 3 gigahertz and more! And they're not even using them! They're playing Candy Crush for gosh sakes!

These people are wasting energy and these super-powered CPUs are a potential fire hazard and we need better regulation enforcement now!

If we restricted high-powered CPUs to people with a license and a documented need, the world would be a safer place for me.

...In all seriousness, 1hp is not serious shit. And motorcycles are significantly faster and more dangerous.

You rebel!

You me and the author are on the same page. Top speed isn't the issue that the author is complaining about, and it's not the reason to get more power. It's about acceleration and hill climbing. That's why he wants more power, and it's why he hates hub motors big and small. In the author's case, it's so that he can power a heavy bike with 5.5" wide tires through deep snow. So many people in this thread don't ride like this, so they imagine 2500 watts powering their skimpy road bike with 110psi tires. He talks about it in this post: https://electricbike-blog.com/2016/12/21/electric-fat-biking...

Unless you're assuming an awesome future with net guns fired from pirate drones, downing the Amazon drones and stealing their wares, this is just the same package theft issue that already exists.

Probably about 300-500 watt-hours of power and approximately 20 watt-hours per mile, so 15-25 miles.

My favorite sources of information about e-bikes come from endless-sphere.com, electricbike.com, electricbike-blog.com, and the /r/ebikes subreddit. Also I've obsessively watched almost every video with "BBSHD" in the title on YouTube in the last several weeks. I will say that the technology is moving pretty quickly and the state of the art today will be the underpowered overweight crap of tomorrow. There is a LOT of room for better technology and the price can come down further as well, all it'll take is an expanding market and competition to bring new innovations to market.

In my opinion the current generation of mid drives are better than the vast majority of hub-drive motors, whether we're talking about the Bosch or Yamaha or Bafang etc... "Better" is a very slippery word. The Gazelle bikes have the Bosch mid-drive system which has torque sensing, but only puts out 250 or 350 watts and your bike cost $3 or 4 thousand dollars. Considering the moderate range and instantaneous power, while it's in line with similar bikes, I feel that it isn't a good value overall. Once bikes with this kind of performance are readily available for, say, $1200, the world will bend around them. But not before.

A bit more info on the 20wh/mile number that I totally made up.

The bike you linked has a 250w motor. Running it at 100% for an hour, if you were able to average 12.5mph for that time, that gives you 20wh/mile.

Based on the watt-hours we calculated earlier, and the manufacturer's claim of 30 miles, we have to assume they're figuring 25mph at 250w of power. This is technically possible according to (http://www.analyticcycling.com/ForcesSpeed_Page.html) but clearly we're in "best case scenario" land.

$500 worth of batteries, $500 worth of motor, $500 worth of bike, and $2500 worth of R&D/marketing/CEO salary expenses.

Batteries have come down in price significantly, just in 2016, I'm sure due to the demand from electric cars. When e-bikes become more popular, and competition increases, the price will come down further. Right now, your best value for an e-bike is a DIY kit.

That bike has a 36v, 8.7ah battery. I have a 52v, 13.5ah battery. Watt-hours is volts times amp-hours, so you're looking at 313wh and I've got 702wh, so more than twice.

That bike has 1.75" tires and I've got big 3" wide tires, and I'm only running about 10-12psi, with front suspension sucking up what feels like half of my pedal power, so rolling resistance is much higher and efficiency is much lower for me.

The "efficiency" is calculated as watt-hours per mile. You'll see different numbers depending on all sorts of factors (pedaling, speed, terrain, tires), but we can just hand-wave it all away (science!) and say 20wh/mile. That gives you about 15 miles and me about 35.

I've only run the battery down once so far, and that was only from a 90% charge, with a lot of mud, snow, and general screwing around. The battery cut out at just over 25 miles.

The law in my state defines a bicycle as a "device having two or three wheels with fully operable pedals and an electric motor of less than 750 watts (one horsepower), whose maximum speed on a paved level surface, when powered solely by such a motor while ridden, is less than 20 miles per hour". So you are allowed to go faster than 20 if you're pedaling.

Bonus fun fact: in my state, you can't get a DUI on an e-bike because it is not a "motor vehicle".

The power output (watts) is a function of (volts * amps) so if you have a 48v battery, you can output ~15 amps and get 750 watts. The amperage output is controlled by software, and these mid-drives are programmable. When you buy the kit, you can have it programmed for 750 watts or 1600 watts for off-road use only.

FWIW, on the bottom is a sticker that says "750W".

250 watts is the legal limit in the EU, whereas most states in the US consider e-bikes providing up to 750 watts of power (about 1hp) as still "bicycles" (meaning no registration, license requirements, insurance, etc). A lot of the retail bike manufacturers are designing motors for the 250 watt limit unfortunately, and although I have it on good authority that many bikes actually exceed their reported power limits, they're still dinky compared to DIY kits.

Here's a video of the installation: https://www.youtube.com/watch?v=SmMtUVO5XZA

The folks that made that video are probably the biggest DIY kit sellers and a big (and controversial) force in the e-bike community. I bought my kit from them including the battery pack.

First: remove the front derailleur (you'll likely have to break the chain to do this, your chain may have a quick-link, otherwise you'll need a chain breaker tool, check YouTube for instructions), remove the shifter cable all the way up to the handlebars, remove the shifter from the handlebars. This mid-drive only has one sprocket on the front, and you retain the stock gears on the back.

Next: remove the pedals, crank arms, and cranks aka front sprockets. Then remove the bottom bracket (special tool may be needed here).

The motor slides right in the hole, you cinch it down on one side, re-attach crank arms and pedals and chain, and from there it's a matter of plugging everything in and a little cable management. Zip ties will be needed.

Here's an incredible riding video to motivate you: https://www.youtube.com/watch?v=tZrleBFAleQ

I agree about the top speed, 25mph on a trail is dangerous for everybody involved.

I want more than 750w of power, not to go faster, but to get up to speed faster after a stop sign/etc. If we could more quickly accelerate up to the limit, we won't be impeding traffic as badly, and it's less of a burden to actually come to a complete stop.

You can get a "race face" front sprocket that has alternating thick-thin teeth. This holds the chain more tightly and makes it much more difficult to fall off.

I built an e-bike last weekend, I have just 35 miles on it so far and I've convinced 1-2 friends to get one already. I love riding but my enthusiasm in winter is severely diminished; this has rekindled it for me.

Anybody here who is interested in an e-bike should strongly consider building up an existing bike rather than dropping $4k on one of the ones mentioned in this article. All the ones mentioned in the article are underpowered and overpriced.

I built a front-suspension mountain bike with a mid-drive motor called a BBSHD. Setup of the bike with the motor kit took about 3 hours and there were no major issues. Some custom tools might be needed to remove the bottom bracket, a bike shop would likely charge less to do it for you than the tools cost.

Last bit of advice, if you do get a DIY kit, make sure to get a high-quality 18650 battery pack. Don't go LiPo and certainly don't go lead-acid. Your battery pack will last longer if you don't always charge it to 100%, but you should charge it to 100% the first half dozen cycles to balance the batteries.

Popehat wrote a post about that. TLDR, Cuomo is wrong. https://popehat.com/2016/10/17/no-it-is-not-illegal-to-read-...

It looks like the True Pundit article (linked above) is the original source for this claim, which is sourced as "according to State Department sources". Then there was a wikileaks email (https://wikileaks.org/clinton-emails/emailid/1099) which has the subject "an SP memo on possible legal and nonlegal strategies re wikileaks", but which doesn't actually mention the strategies and only says "The result is the attached memo, which has one interesting legal approach and I think some very good suggestions about how to handle our public diplomacy". The attachment is not provided as far as I can tell.

IMO, it was likely a joke.

Reading this and then going back and reading his SF arrest story (linked in the article) is a real contrast.

I agree; I think it's despicable that Tesla is acting in such a defensive manner.

-- "No force was detected on the steering wheel for over two minutes after autosteer was engaged," said Tesla, which added that it can detect even a very small amount of force, such as one hand resting on the wheel.

"As road conditions became increasingly uncertain, the vehicle again alerted the driver to put his hands on the wheel," said Tesla. "He did not do so and shortly thereafter the vehicle collided with a post on the edge of the roadway." --

Bruh-slow the car down then. If you're storing information that points to the fact that that the driver is not paying attention, and you're not doing anything about it, that's on you 100%.

We are in the midst of a transition period between autonomous and semi-autonomous cars, and blaming the driver for the fact that the car, in auto-steer mode, steered into obstacles, is counter-productive in the long term. You need to make auto-steer not work under these conditions. The driver will quickly figure out the limits of your system as their car decelerates with an annoying beeping sound.

There's a YouTube channel "Bigelow Brook Farms" where the broadcaster designed and built a geodesic dome greenhouse (lots of passive solar) and does year-round aquaponics. I think he lives in Delaware or somewhere in the NE USA, it definitely gets cold there. He has 4-5 years worth of growth in this greenhouse and lots of lessons learned. I recommend it if you're interested in the topic.

It varies slightly by state, but many places you can have up to 750-1000 watts and up to 20mph unassisted on flat ground and still have a bicycle, meaning no license or insurance requirement. You'll typically pedal close to 20mph on flat ground. I find these limits to be reasonable.