technology – Matt Simerson

Lectric XP brake upgrade

I have a Lectric XP 2.0 e-bike I purchased in 2022. I ordered it with the cargo package (front and rear racks & baskets), intending to use it to reduce car trips for local errands and grocery shopping. Without any planning I can easily carry home two grocery bags on it. With a couple bungee cords, I can carry home a fair bit more.

The rather basic single-piston brakes with 160mm rotors that came with it are good enough to stop the bike and I on most terrain. However, I live in Seattle and we have good sized hills out here. When riding down a hill with a load of groceries, a fair degree of planning is required to bring the bike to a stop on time. It seems Lectric was made aware of this deficiency because the XP 3.0 has upgraded the brakes to 180mm rotors and hydraulic brakes.

Today I upgraded my XP 2.0 with a TEKTRO 203mm rotor on the front and I replaced the Zoom single-piston calipers with XTECH HB-100 hydraulic dual-piston calipers. The improvement in stopping power was immediately noticeable and I’m looking forward to testing my next grocery run.

PSA: shun TurboTax and H&R Block

Since I wrote in 2019, the biggest tax prep companies continue to spend tens of millions to prevent making tax filing simple and easy. They’ve been fined for bait-and-switch, hiding the Free File service they were paid to offer, and overcharging Free File eligible taxpayers. Instead of giving Intuit another nickel, use Cash.app taxes, a local preparer, or file paper returns.

haproxy dynamic TLS reloads

Haproxy has a great newer feature that lets one dynamically reload TLS certificates. I explored this today because I’ve had two instances in the past few months where haproxy stopped serving for time, at midnight when the cron job that renews TLS certs kicks off. I think it’s an edge case involving web sockets with a 1 hour timeout and a handful of TLS certs all renewing in close succession. Regardless, not having to reload haproxy at all sounded attractive.

The page above has this example for sending the certificate to haproxy’s admin API:

echo -e "set ssl cert /etc/haproxy/certs/site.pem <<\n$(cat ./new_certificate.pem)\n" | socat tcp-connect:172.25.0.10:9999 -

After exploring the vagaries of echo and echo -e and staring at the output for a few too many times, I finally determined the cause of the failure. The certificate I was attempting to send has a stray newline character. ??‍♂️ The solution is simple, assure your boundary character doesn’t match the data:

echo -e "set ssl cert /etc/haproxy/certs/site.pem <<\n$(grep . ./new_certificate.pem)\n" | socat tcp-connect:172.25.0.10:9999 -

e-cells e-bike brakes

In July of 2020, we purchased a 600 watt dual-motor AWD fat-tire e-bike from ecells.com. The bike has a motor in each wheel. The frame is super beefy and fairly heavy. It has been a hoot. Mostly we ride it on paved urban trails here in town, where the beefy frame and rack lets it excel at hauling home groceries. It’s more at home out at Meany Lodge where we ride it up and down forest roads in the mountains where the low-pressure fat tires provide abundant traction and good suspension. It can really haul on the loose gravel roads.

Last weekend I took it on a ride near Mailbox Peak with a group of friends. The bike did quite well at helping me ride up the mountain like I was 20 years younger and 20 pounds lighter. Where it wasn’t so awesome was blasting down the no-longer-maintained-and-sometimes-washed-out logging roads. I wanted to downhill hard and fast, like on my still-awesome Raleigh M-800 mountain bike. The E-cells brakes need to stop 70# of bike, 10# of gear, and me, while thrashing downhill at 30-35mph. I was experiencing significant brake fade and needing to plan my braking. The brakes lack authority. So I went shopping for upgrades and learned a few things.

Brake Pad Types

metallic – longest life, greatest stopping power, more noisy
organic/resin – quiet, good initial bite, glaze over / fade under heavy braking
semi-metallic – combination of the two

The pads that came with my bike are Tektro A10.11, which is a sintered (semi-metallic) ceramic pad. That pad is no longer listed on the Tektro web site. The nearest OEM replacement is the E10.11 ($15), which is sintered organic. A higher performance metallic pad is the Tektro P20.11 ($24) which I have ordered. They provide a small boost in stopping power, but more importantly, they won’t fade under prolonged heavy braking.

Rotor Size

Bike rotor sizes start at 140mm and go up. The increased diameter of larger rotors provides more mechanical advantage so less friction is required to get the same stopping power. Larger rotors provide more thermal mass to absorb heat and more surface area to dissipate heat. Common e-bike rotor sizes are: 160, 180, and 203mm. Most e-bike forks are set up for 160mm rotors. Cheap ($10-15) adapters enable those forks to work with 180 and 203mm rotors.

The E-cells 600 comes with Tektro Aries mechanical disc brakes on 160mm rotors (front and rear) with adapters. Because the front wheel provides ~70% of the stopping power, it’s quite common to use larger front rotors: eg. 203mm on the front and 180mm on the rear. The higher spec E-cells 700 and 1000 models have exactly that setup with hydraulic calipers.

Disc Brake Types

• Mechanical disc brakes are inexpensive, reliable, and solidly better than rim and other brakes of yesteryear. Like legacy brake systems, they are cable actuated. They have a single moving piston which warps the brake disc into the other pad, compressing it and providing braking power.

• Hydraulic disc brakes replace the wire cable with hydraulic fluid (DOT or mineral oil) which provides equal force on two opposing pistons. The reduced friction and doubling of pistons provides more braking power with less effort. Testing (varies a LOT based on bike and system) shows a 40-70% reduction in braking distance with hydraulic disc brakes.

• Hydraulic 4-piston disc brakes are fairly new, fairly rare, and expensive. They are the go-to option for higher speed (22+ mph) and cargo eBikes. The piston engagement is progressive: you initially get two pistons braking and as the rider pulls harder, all 4 engage for massive stopping power. That much braking power would be dangerous on lighter bikes, but it’s needed for fast downhills on heavy bikes. ? ? ?

• Hybrid: there exists a hybrid, the Juin Tech M1 cable actuated hydraulic brake. They’re intriguing, promising substantially better stopping power than mechanical disc brakes for a modest upgrade ($160) price and a very simple install. The only “not paid” review data I found is that they are an incremental improvement upon mechanical disc brakes, not a step-change improvement like going from mechanical to hydraulic.

e-bike brakes

Another layer of complexity added to e-bike brakes is that the brake levers need cutout switches that disengage the motor when braking. The vast majority of bicycle brake systems don’t have this feature.

Combine the newness of 4-piston brakes with the much smaller ecosystem of brake levers with cutoffs for e-bikes and the choices get very narrow. As in, the full list is: Tektro E-725, Magura MT-5, Magura MT-7. I opted for the Tektro because the Magura’s have plastic fluid reservoirs.

The switch to metallic pads and 4-piston brakes should suffice. If not, my next move will be upsizing the front rotor to 203mm, for another ~12% increase in braking power.

2021 Michigan Road Trip

This summer we drove to Michigan to visit my dad and celebrate his 75th birthday. Because I’m still playing the Superchargers Visited game (2019 trip, 2020 trip), I had to choose routes that didn’t overlap with previous ones. Fortunately, that left lots of fresh ground to cover and we spent a lot more of this trip on highways and less time on the interstates.

The slower pace and smaller roads made road tripping more fun as I got to experience that joy of discovery that is rare on freeways. Sometimes the discoveries are, “huh, this route through Kansas is every bit as interesting as every other route through Kansas.” Other times, like driving through northern Wisconsin and Indiana, we stumbled through some lovely little towns and cities that were well kept and seem to have avoided the fate of so many rustbelt towns.

This trips haul was 86 unique superchargers visited over 9 days of driving.

PodSwap

A year ago I gave my old AirPods to Kayla because the batteries didn’t last very long. Now they’ve reached the point where they only last 5 minutes on a charge. I’m pretty handy at replacing batteries in iPhones and  Watches so I looked up info on how to do it for AirPods. And then I looked at how much Apple charges to replace the batteries ($49 per Airpod, $98 for the pair). And then I found PodSwap. So I ordered a swap for $60. If you have an old pair of AirPods needing new batteries, try them and save 10%.

Superchargers Visited

Superchargers Visited is a silly and fun Tesla owners game I’m playing. I have a Tableau page showing the Superchargers I have, and have not (default view) visited.

The game might be one of the reasons I drove to Tampa for a meeting instead of flying. Fun facts: about 8k miles driven, 146 Superchargers visited, 11 days, and $409.23 in electricity.

Note to my future self: with two drivers tag team driving, keeping the wheels in motion when not refueling, expect to cover about 1,000 miles per day in fair weather.

FrankenYak

I recently obtained this lovely new yard ornament named Yak.

Yak is 1/3 of our snowmobile fleet at Meany Lodge. Our main winter transport for the 3 miles from Crystal Springs Sno-Park to the Lodge is Tomcat which can haul 35 people + gear. We use the snowmobiles for the many smaller transport tasks such as hauling large sleds full of groceries and gear to and from the car park.

This machine suffered a mechanical failure and the cost of repair exceeds the machines value. Instead of disposing of Yak, I intend to strip the 4-cycle ICE powertrain and replace it with an electric motor and a DIY Li-Ion battery pack. The project is just getting started as I’ve purchased a box of battery cells to experiment with and started searching for the lightest and most efficient 100HP motor I can find.

When it is complete and we have demonstrated a minimum viable product (the ability to drive to and from the Sno-Park with sufficient reserve capacity), I hereby promise to impersonate the canonical “It’s Alive” scene.

EV FAQ: how long does it take to charge?

One of the most common questions people ask about our Electric Vehicles is how long it takes to charge them. I’ve answered this in a variety of ways but I’m not sure I’ve ever fully answered the question. Part of the reason people are concerned with charge time is because one of the primary inconveniences of driving a car has been gassing it up. You must drive to a station, wait for a pump, insert a payment card, wait for authorization, select a fuel type/grade, start the pump, and then stand outside in the weather to monitor it. With a BEV, the vast majority of charging happens in your garage or driveway. Thus my answers tended to highlight this difference in “filling up” paradigms.

“About 30 seconds. I plug it in when I get home and unplug when I leave.”
“It depends on what I’m plugged into.”
“It doesn’t matter, because it charges while I’m sleeping.”

Those answers are valid, but they don’t tell the whole story. That’s because the story is complex. Let’s start with the simplified version.

Level 1 adds 5 Miles of range Per Hour of Charging
Level 2 adds 20 MPHC
DC fast charging adds over 100 MPHC.

EV Charging Levels

Levels 1 and 2 use standard household (AC) current. The vehicle has an onboard charger that converts household AC current to the DC current which is stored in the battery pack. To charge at levels 1 and 2, a special adapter called an Electric Vehicle Supply Equipment (EVSE) is used. Every EV comes with an EVSE and they all share the common J1772 connector.

Then there is DC fast charging. Since the car doesn’t need to convert the DC current, it can charge the battery as fast the battery can store it. In fact, the car tells the DC charger what rate it can accept and then the charging station delivers as much as it can, without exceeding the cars limit. There are several DC fast charging standards including CHAdeMO (Nissan), Supercharger (Tesla), GB/T (China), and SAE Combo/CCS (everyone else).

Charge Times

Level 1, also known as trickle charging, is the slowest charge rate and uses standard 120V wall outlets that you can find nearly everywhere. On a typical 12-hour overnight charge, a BEV will gain about 60 miles of range. Considering that most people travel under 40 miles per day, L1 is often good enough. Older BEVs like our leased ’13 and ’16 Leafs included an EVSE that supported only Level 1 charging. We found it sufficient in all but the coldest week or two of the year.

Level 2 adds 20 MPHC. Level 2 is the most common and the EVSEs are rated by the maximum power they can deliver. The most common EVSE uses the 50A NEMA 14-50 plug, draws 32 amps continuous, and adds about 240 miles of range overnight. The NEMA 14-50 is the same outlet commonly used for electric ranges, ovens, generators, and RVs. You can often find the 14-50 plug in kitchens, garages, and campgrounds across America. The EVSE included with our ’19 Leaf and ’19 Tesla Model 3 both sport a NEMA 14-50 plug. If your garage doesn’t have one, getting a NEMA 14-50 outlet installed is a good bet. Be advised though, ask your electrician for an “oven outlet,” as many electricians have charged hundreds of dollars more for an EV outlet than the identical oven outlet.

If you already have a 240V outlet of any sort in your garage, there are 3rd party EVSEs with plugs matched to nearly any standard 240V outlet. A dryer, welder, air conditioner, or generator outlet in your garage is sufficient. Lower rated (~3.3kW) EVSEs can be found for $200-$300 whereas a reputable (ChargePoint, Clipper Creek, JuiceBox) 8kW EVSE will run about $500. If you have a Tesla, you can buy $35 adapters for the included EVSE for all the common 240V plug types.

DC Fast Chargers require more electricity than a house and are industrial machines. They are typically found at commercial buildings (like Nissan dealers) and along major highways. Whereas L1 and L2 stations are typically used at home, DCFCs are typically used on longer trips. Here’s a few examples of DC fast charging rates:

Our Tesla Model 3 Long Range can add 125 miles in 15 minutes, or 267 MPHC
The Chevy Bolt & Nissan Leaf can add 30 miles per 10 minutes, and 120 MPHC.

Careful readers may have noticed that the peak charge rate is substantially higher than the MPHC. That’s because Li-Ion batteries (just like in your phone/tablet/laptop) must be charged slower as they approach full. The tapering is much more pronounced with DCFC and it’s done to protect the battery. In fact, it is the car that tells the charger the rate at which it can accept power. Most EVs charge at their full rate up to about 80% and then taper. Because of tapering, long road trips in a BEV mean your trip will take less time if you charge to 80% and then leave for the next charging station. Tesla actually does this for you–it will charge enough to get to the next Supercharger (plus some margin) and then suggest hitting the road.

Level	Volts	Amps	MPHC	kW
1	120	12	4-5	1.4
2	240	35-80	20-50	3.3 – 15
DC – CHAdeMO	500	125	up to 140	usually 50, up to 62.5
DC – CCS	200-1000	< 500	depends	up to 350
DC – Tesla SuperCharger	480	300	267	140

Tesla has ruined me

Habits are funny things. We develop them after performing a repetitive task for about 2 months. Having formed the habit, we continue doing the same actions but we tend to forget that we used to need to think about the actions. Habits let us be unaware that we’re still performing them.

Having driven autos for nearly 3 decades, I had a collection of driving habits I no longer thought about. Driving my Tesla Model 3 for a while has let some of them fade away. This came into focus this weekend while driving 400 miles to Moses Lake and back for a math competition.

Braking. With a Battery EV (BEV), letting up on the accelerator initiates regenerative braking. The car uses the motor to slow the vehicle and store that kinetic energy in the battery. It doesn’t take long to become proficient at one pedal driving. About the only time braking is required is to bring our Tesla from a slow roll to a complete stop. While driving an older vehicle on this trip, I found myself thinking about braking: when to start, how much, why doesn’t this car have “brake hold,” and “oh yeah, I must press that brake pedal!”
Starting: For 100 years cars had ignitions. Starting a car is a series of steps:
- Fish the keys out of wherever you stowed them
- Insert the correct key into the ignition
- Twist the key to start the engine
- Release the key immediately after the engine starts
- Depress the brake and/or clutch
- Release the emergency brake
- Shift into gear
- Press the accelerator to drive away
- Manual transmissions also require a synchronized release of the clutch and accelerator. Newer hybrids remove a step as they automatically start and stop the gas engine as needed. Some cars have smart keys that let you leave your key in your purse or pocket.
Until you try to teach someone else to drive, or get used to driving a BEV, it’s easy to forget how elaborate the startup ritual is. A Tesla has no start button. The steps in our Tesla are:
- Step on the brake and shift into gear.
- (if enabled): enter the PIN code.
- Press the accelerator to drive away.
Stopping a typical car has a similar sequence:
- Shift the car into park (or gear)
- Turn off the ignition
- Set the parking / emergency brake
- Exit the car (and wait for everyone else to exit the car)
- Lock the car
- Store the keys
To stop driving a Tesla, you shift into park, get out, and walk away. If you’re at home and the battery is low, you might also pause to plug it in. A Tesla sets the emergency brake upon shifting into Park and releases it upon shifting into another gear. It automatically locks the car as you walk away.
My phone is my Tesla key and it can remain in my pocket. There is no ignition nor clutch. There’s not even a transmission: just a gearbox with a single gear. As a result of not needing to perform the typical sequences for a couple months, it’s entirely possible that over the course of 400 miles and 8 stops that at least once I:
- tried opening the car door before unlocking the car.
- got in, fastened my seatbelt, looked at the dash expectantly, unfastened my seatbelt, fished the keys out of my pocket, stuck the keys in the ignition, and refastened my seatbelt.
- was reminded by the sound of the running engine to get back in and turn the car off.
- started driving before releasing the emergency brake.
- returned to the car to lock it, upon remembering that it won’t lock itself.