Category: Uncategorized

UL: DIY box fan filters are probably safe

You’ve seen the formula: 20 inch box fan ($30) + 20 inch furnace filter ($10) + duct tape ($5) = a quick, effective, DIY home air purifier for under $50.

How effective are they? I measured my homebrew filter (made with a MERV11 filter), and it dropped the indoor air quality AQI from 57 to single digits in a 10 x 10 room inside of an hour.

In 2020, we eventually exceeded AQI 400 from very high PM2.5 due to California wildfires raging nearby, but my indoor air quality was fine thanks to DIY filters, along with higher efficiency filters for my central air conditioning.

It’s always been in the back of my mind, however, that we’re using electrical appliances in ways they’re not tested for. Fans are tested for safety with unobstructed air flows. I’m a software engineer but my entire career has been working with hardware design teams. I’ve seen firsthand what happens when fans are operated in ways outside of their intended design: the motor windings heat the fan’s external casing and things melt and catch on fire.

I’m thrilled to learn that Underwriters Laboratories, which tests appliances for safety, thought of this too. With help from the US Environmental Protection Agency, Dr. Aika Davis and Dr. Marilyn Black tested box fans with MERV13 filters in various conditions and learned that modified box fans don’t catch on fire.

For the test, UL attached probes to measure the temperature for the motor housing, motor windings, power cord at the motor, fan guard, output air, switch, and ambient air. They also measured voltage, amperage, wattage, and airflow.

In their “Highlights of findings,” the researchers dryly note “exterior surfaces that can come into direct contact with people remained below the first-degree burn potential” and “fire ignition was not achieved with any of the filter/fan test scenarios.”

The ambient air temperature during the test was a cool 20°C. UL’s testing notes the motor windings peaked at 92°C in the worst case scenario (two heavily obstructed filters), which is just short of UL’s safety limit of 105°C, so keep this in mind if you’re in a hot room, and don’t put your DIY filter near easily ignitable items.

You can read the full report as a PDF here. The nerd in me appreciates reading about the testing methodology. This might make a decent middle school science fair project. I’m posting this to a blog about bicycles because we spend a lot of time outdoors and need to think about our lung health. Personally, I’m among the high percentage of endurance athletes with ashtma and I strongly prefer clean air over polluted air.

The Jiangsu Snail and their solar powered scooter

Jiangsu Snail Zhixing Technology Co.,Ltd solar scooter

Welcome to the blog that discovers the cycling-adjacent weird and wonderful tidbits as I walk the aisles of the Sea Otter Classic 2023 Expo. Today, I talked with the two representatives of Jiangsu Snail Zhixing Technology Co.,Ltd , which manufactures solar-powered scooters.

Photovoltaic panels cover the front and the deck of this scooter, which I’m told can charge the battery in roughly six to eight hours on a sunny California day. They’re trying to break into the shared mobility market with this scooter. They believe that solar charging can benefit scooter share companies that currently must pay contractors to charge public scooter batteries.

I’m curious why they named they include the snail in their company name. These slimy, shelled gastropods don’t generally carry a positive connotation for Western consumers, so I asked, “Why snail? Does the snail have special significance in Chinese culture?”

They told me there’s no special meaning behind the snail, but they wanted to convey the idea that this scooter is snail-like in that snails keep moving along despite their (ahem) snail’s pace. I suppose the Western equivalent might be “slow and steady wins the race” from Aesop’s fable of “The Tortoise and the Hare.”

That’s when I noticed the name of their scooter — the “Sunail” — is a pun. It’s a sun-powered snail that’s always on the go despite its languid pace. Get it?

The Snail Scooter company’s booth isn’t far from the tire bridge at Sea Otter if you’d like to see it for yourself, or watch their promotional video.

What if Taco Bell and State Bicycle did a brand collaboration?

I don’t usually like to republish press releases without editing, but this brand collab is too good to not pass along. I’m at the Sea Otter Festival 2023 where I’ll look for State’s Taco Bell goodies.

Taco Bell is joining forces with Arizona-based bicycle company, State Bicycle Co., to bring the heat with a new line of limited edition custom accessories, gear and apparel today. This collaboration also brings a Taco Bell twist to State Bicycle Co.’s “DGAF” Klunker bike for the ultimate ride. The collection will be available to purchase starting on April 20 via State Bicycle Co.’s website while supplies last. 

This capsule collection features the following:

  • State Bicycle Co. x Taco Bell: Klunker Bike: The Klunker Bike is a retro-inspired mashup of a beach cruiser, mountain bike and BMX, perfect for biking to grab tacos at Taco Bell. The State Klunker eliminates all the complications of modern-day bikes, focusing on recapturing the consumer’s favorite childhood memories of riding, so they can mash, coast, take a jump or lay down skids via the coaster-brake-equipped hub. From the bike’s built-in bottle opener on the seat tube, fans can find this model decked out with the iconic Taco Bell logo and signature purple, pink and yellow brand colors. The model even features a fork lined with “Live Mas.” The hype doesn’t stop there; with every bike purchased, guests will receive a complimentary Taco Bell x State Bicycle Co. custom frame bag until supplies last. The custom bag will also be available for individual sale at $69.99. 
  • Accessories: Adding some fuel to the Fire! ride, the collection features custom bike grips and bar ends embossed with the Taco Bell logo. To top it off, taco-loving fans will receive these accessories in a Cravings Box-inspired packaging. 
  • Biking Apparel: Consumers can choose from a spicy and stylish range of apparel, including a black and white monogrammed kit (jersey and bib), MTB t-shirt and a limited-edition handlebar bag to pack fan-favorite Taco Bell items. ​ 

According to State Bicycle Co, this Taco Bell x State Bicycle Co. marks the brand’s first collaboration between food and transportation, giving fans a fresh perspective on biking in true style while expressing their love for both brands.

Diamondback updates Haanjo gravel bikes

Diamondback will exhibit their updated Haanjo gravel bikes at the Sea Otter Classic 2023 taking place this week in Monterey, California.

The models range from entry level commuter bikes to fully-featured, carbon do-it-all gravel bikes, that Diamondback says excel on both road and dirt.

A major part of the redesign includes changing the axle-to-crown length on the new Haanjo frame so it can be compatible with Diamodback’s Haanjo Carbon fork, Rockshox Rudy or the SR Suntour GVX with travel ranging from 30mm up to 60mm. This new frame can be found on the Haanjo 4 EXP through Haanjo 8C, and will also offer an increased number of attachment points to fit water bottle cages or add a bag on the top tube just like Jason says he likes to do.

Diamondback Haanjo detail of top tube / seat post / rear triangle area.

In addition to the redesigned frame, the new Haanjo 7C EXP has a Rock Shox Rudy 40mm Travel front fork and the Haanjo 4 EXP has a SR Suntour GVX32, 60mm Travel Suspension Fork. Dropper posts are also added to the Haanjo 4 EXP through Haanjo 8C.

The new Haanjo collection ranging from $1,000 – $5,700 will be available online and at retailers in 2023.

Sealed bearings are not entirely waterproof

With December, January, February, March, and April showers come flooded roads and paths. We all do what we’ve got to do to get through these areas, but it’s best to avoid biking through deep water. Prolonged water contact will damage any type of bearing surface in your bicycle, but don’t get too confident if you think you have sealed bearings: sealed cartridge bearings in your bottom bracket and hubs are not completely waterproof, especially with prolonged immersion.

Embed from Getty Images

Your bicycle likely has different types of bearings, but I’ll mostly discuss ball bearings here. These reduce rotational friction while supporting loads. On your bicycle, you probably have ball bearings in your wheel hubs, your bottom bracket (the mostly cylindrical thing at the bottom of your bike frame where the cranks attach), and in your steering tube.

The ball bearings come in various styles: cup and cone, cartridge, and sealed. All of these are used on bicycles, and all of these, including sealed bearings, are subject to water intrusion.

Sealed bearings are “sealed” by a plastic cover to protect the bearings and grease inside the cartridge from dust contimination. The covers also protect against splashing, but provide little to no protection against total immersion. When you dunk the moving parts of your bicycle into water, the water contaminates the grease. Even if the water is completely clean, the steel bearings begin to rust and no longer provide a smooth, low-friction surface.

Maybe you’ll be fine biking through deep water, maybe not. I personally try to avoid riding through anything deeper than the bottom of my bottom bracket. If you do ride through water deep enough to soak your bottom bracket, do what you can to dry the insides out.

Blogs about everyday cycling?

Arleigh AKA BikeShopGirl asks about blogs that cover family, utility, or everyday cycling.

I took a look at my feed, and I realize most of the blogs I follow that still publish anything focus on advocacy and news. 

So how about it, you all? What blogs can you point me to that celebrate and encourage everyday cycling by everyday people?