You are absolutely correct!

I recommend you check out the Big Mac Index as it makes this stuff easier to understand.

The fact that $1CAD is worth less than $1USD or €1 doesn’t mean much. It’s just numbers printed on a screen/plastic/paper. What matters is what it buys.

The Big Mac Index was developed by The Economist to make this easier to understand. It calculates what what a Big Mac costs in each country against a common currency. It doesn’t matter if $1USD = $1CAD or $1,000CAD. What matters is what that buys.

In 2022 - the year the graphic in the posted link corresponds to, a Big Mac cost $5.35 in the US and $5.17 in Canada when using the same (USD) currency. This implies that the effective difference in purchasing power is a paltry 3.5%.

If a burger is $5USD in the US and $7CAD in Canada, and the exchange rate is $1USD = $1.40CAD then those prices are the same.

I was just in Japan where I was paying 5000¥ for a fancy coffee - which was about $4.5CAD - roughly what I’d pay here in Canada.

Grifters gonna grift.

My partner and I don’t have ANY tv’s.

Neither of us are super into TV or film in a way that builds creativity or community (we don’t critique the technical or artistic merits of pieces, and we aren’t into anime or other genres where there’s potential to build a community around a shared passion). When we turn on the TV, it’s to turn off our brains. We decided to not build a shrine to turning off our brains.

We have a laptop with a good screen and speakers that we use when we want to watch something together.

I checked belts, they’re good.

I’m wondering if there is enough of a weight difference between the old and new extruder to have fouled the configuration.

No, checked that and the period of the undulations is speed dependent

It’s hard to overstate the impact this will have on small frame builders. Head tubes, bottom bracket shells and dropouts are brutal to fabricate in small quantities and Paragon has been THE North American source for decades. Of my 4 bikes, three have PMW hardware.

That’s some impressive reporting

Ah good, we can talk physics.

Newton’s Second Law

Okay, let’s start with Newton’s second law:

F=m*a

but we’re going to flip it around to

a=F/m

so that acceleration of a body is equal to the force acting on that body divided by its mass. What this tells us is that for a given force f applied to a vehicle of mass m, the vehicle will accelerate at rate a.

Where does that force F come from? From the tires acting against the pavement per the lever arm equation:

t=F*d

or, a force F working through a lever arm of length d will produce a torque t, but again, we’re going to flip it around a bit to give us

F=t/d

Which tells us that a given torque t operating through wheels of radius d will produce a force on the pavement of F.

Now we’re going to combine the two to give us

a=t/(d*m)

So, acceleration is directly proportional to the applied torque and inversely proportional to mass which absolutely supports what you are saying at first glance.

HMI

HMI is an acronym for Human Machine Interface which is a whole mechanical design field built around helping humans interact with complex machines like cars. Now I have to admit some ignorance here, but I don’t know what type of vehicle you drive so I’ll start simple.

In my vehicles, both gas and electric, there’s two pedals specifically related to acceleration. The accelerator (sometimes called a throttle) and the brake pedal - and these pedals are remarkable devices.

The accelerator (negating regenerative braking that we’ll touch on later) controls positive acceleration while the brake controls negative acceleration. Basically, the accelerator makes us go faster (forward or back) and the brake slows us down. But here’s where it gets nuts - these are proportionate input controls. It isn’t like a light switch rather, it’s more like a dimmer - the more you press on the pedal, the more acceleration you get. The way this is accomplished is by controlling the torque applied by the motor. This is key - we can control the torque output of the motor.

Puting it all together

You are absolutely correct that the electric motors in EVs can generate absurd torque which, as we’ve seen, results in incredible acceleration. I certainly had some fun when my EV was new. But, 99% of the time, I’m driving in traffic or on the highway and my accelerator inputs are very light - the motor is generating only a small amount of torque it’s capable of producing.

Gas cars operate in a similar, albeit wildly more complex manner (the accelerator pedal controls the amount of air getting into the engine, then a feed forward control mechanism is guessing how much fuel is needed and a feedback system monitors for the presence of unconsumed oxygen or uncombusted fuel in the exhaust). The important thing is that both are capable of delivering variable torque based on operator inputs.

So let’s imagine we have two cars stopped side by side at a stoplight that turns green. Both vehicles can use their accelerator pedals to control their rate of acceleration and they both accelerate away in a nice sedate manner.

As I mentioned in a previous post, an Ioniq 5 (EV) weighs about 2000kg while a Rav4 (gas) weighs about 1700kg. The EV therefore weighs roughly 15% more. If both vehicles leave the line at the same rate of acceleration the torque output from the EV will need to be 15% higher.

a=t/(d*m)

That then takes us back to Newton’s Second Law and thus the longitudinal interaction force between the tire and pavement will be about 15% higher - which is not nothing, but let’s add some context.

Perspective

The coefficient of drag Cd for the Ioniq 5 is 0.288 vs 0.310 for the Rav4 - about 8% higher. The drag equation is

Fd = 1/2 r * u^2 * Cd*A

where r is the air density, u is velocity, and A is the reference area. In this case r and A are equal (well, mostly equal in the case of area) for our ICE and EV examples.

What this equation tells us is that at a given speed, the Rav4 requires 8% more driving force to overcome wind resistance. This isn’t just during the acceleration phase, but at all times.

It also shows us that drag forces go up with the square of speed. That means that if you increase your speed from 100 to 115km/h (15% increase), the drag forces go up by 32%.

So if we compare the EV to the ICE vehicle under cruising conditions, the friction forces between the tire and the pavement are HIGHER for the ICE vehicle in this example.

Even more than that, the impact of increasing speed dwarfs both the impact of mass and the impact of the coefficient of drag.

Summary

I haven’t come across a peer reviewed body of knowledge that compellingly argues that an EV and an ICE vehicle, driven similarly, will have substantially different rates of tire wear. Rather, speed, proper inflation, and road surface seem to be much more significant. The bulk of reports of accelerated tire wear come from journalists and influencers reviewing vehicles - groups who likely enjoy the acceleration that EVs are capable of, but don’t have to use.

The tire thing is FUD in my experience - and I haven’t seen anything other than anecdotal evedince that under similar driving patterns and styles there’s substantial differences in wear. My Ioniq 5 for example only weighs ~15% more than a Rav4 and less than a Honda Pilot.

When I drove a Subaru STi, I shredded my first set of tires. My station wagon, that weighed more, the tires lasted forever because I drove like an old man. With EVs, if you have fun enjoying that instant torque by punching it off every stoplight, you’ll definitely shred some tires. Accelerate smoothly and I don’t see why tires would see substantially shorter lifespan - which is what I’m seeing from my personal tread wear so far (but that’s anecdotal and therefore of extremely limited value).

Can do!

Yea, I need to make it simpler, thanks for the feedback.

Thanks for the feedback, I’ll add a link to a blank calculator where you can load the details of the vehicles you want to compare.

Hmm, depreciation on my Ioniq isn’t anything like that bad. And I had a fuel injector quit in my last car at 130k. The cost of replacing all four injectors was a heck of a lot more than quoted. I intentionally lowballed service costs for ICE vehicles because people tend to (dramatically) underestimate what they spend on maintenance.

Also, the tire thing is FUD. Tire wear is higher IF you regularly use all that torque. If you floor it off every light (which is very fun) you shred your tires. If you drive conservatively there’s minimal difference. My Ioniq 5 weighs about 2000kg, a non-plug-in Rav4 hybrid weighs 1700kg, and a Honda Pilot is around 2200kg so the weight just isn’t that different from other vehicles.

Are you kidding me? Your blood is like liquid gold - I remember a nurse telling me that they won’t let O- doners give plasma because the need for O-neg is so high. You are a rockstar for donating!

I’ve got A+ so there’s no shortage and I spend my lunch hour every Thursday getting pampered by staff. Apparently there’s studies starting to show that regular blood or plasma donations come with health benefits - kind of like changing the oil on your car you flush out some of the gunk circulating in your blood.

We should be friends.

I’m 90% sure this is a troll. Don’t feed trolls.

animatedknots.com - amazing step by step on how to properly tie things. The downside is that there are a lot of knots that are either hyper specific or more decorative than anything. I climb and sail - both are knot-heavy. 95%of the time I use one of five or six knots/hitches. I’d focus on the utilitarian knots personally. These are the knots that can accomplish real stuff - but if you get them wrong, could be fatal in the wrong circumstances.

• Simple overhand - great for keeping a loose end from flopping around, connecting two ropes (need long tails or a secondary knot to keep it from moving), or joining webbing (known as a water knot in this context)
• bowline - great for tying around things like if you want to anchor something to a tree
• figure 8 - the go-to for tying yourself into a rope when climbing. I rarely use it anywhere else as it’s bulky and difficult to untie if loaded hard. A bowline can be used in its place for tying in, but the big advantage of the 8 is that it’s easy to visually check. Every few years a miss-tied bowline kills a climber.
• clove hitch - this one is super underrated. It looks like you just wrapped a rope around something but it self tightens thanks to the way the strands lie over each other. It’s also super easy to adjust.
• trucker hitch - it’s really just a couple of overhand knots, but this one is my default for lashing down loads because you can get the rope super tight. This is how I tie my canoe down to the roof of the car.
• fisherman knots - killer for connecting ropes - or making non-load-bearing adjustable loops (bracelets, necklaces), or tidying up loose ends.

Bonus knots *alpine butterfly - gives you a load bearing loop in the middle of a rope without requiring access to the ends. An overhand on a bight also gives a loop, but the overhand can move when loaded. Alpine butterfly stays where you put it, looks cool, and is fun and easy to tie. *prussic - this hitch can slide along a rope when unloaded and then locks when you apply weight. This let’s you move up or down a fixed line. A Texas Prussic involves one prussic attached to your harness and one free but with a foot loop. Hang on the harness prussic, slide the unloaded foot one up the rope. Stand up on the foot one (locks in place) and slide the unweighted harness loop up the rope, sit back down in your harness. Congrats, you just ascended 100mm up a rope. Rinse and repeat until you get to the top or reverse the process to go back down.

But, but, I need a photo of this performance mod…

https://ceip.abmunis.ca/residential/upgrades/

There’s the program website. You might be able to roll the roof upgrade into the funding - max is $50k. Some friends did all of their windows and some other stuff. You get a max of 20 years to repay and most energy retrofits pay for themselves in just a few years.