February 24, 2015
Posted by FLO Cycling at Tuesday, February 24, 2015 Labels: Aerodynamics , FLO Research & Development , Tire Study
Over the last few days, I've been able to get out on the road to test the sensors and my carpentry skills. Everything has been going really well. Here is a quick update on what we've been doing.
The first ride was at a slow-paced eight mile trip. I wanted to make sure things were working properly before I spent too much time on the road. I wasn't using GPS or power for this ride. Below I've added a quick video clip of the ride.
The Results - Percentage of Time at Each Yaw Angle
The first thing I looked at was the percentage of time spent at each yaw angle. I started considering measurements at three mph. The data logger records measurements every second so I counted the number of measurements in for each yaw angle. Once I had the number of measurements, I could determine the percentage of time spent at that yaw angle. Finally I looked at cumulative amount of time in a yaw angle range. The bold section in the table below shows where the majority of the time was spent.
The Results - Average Yaw Angle at a Relative Velocity
The next thing I looked at was the average yaw angle for a specific relative velocity. I selected all of the yaw angle measurements taken at a specific relative velocity and averaged them. Here is what I found.
My first thought is that eight miles is not going to tell us a ton. My second thought is that it looks like the rider/air interaction is different than I thought. Old studies we've read have shown the the average yaw angle is between 10-20 degrees of yaw. These results show something completely different.
We've already started gathering more data and are working on more specific tests to get ready for our tire study. Stay tuned for more updates.
February 21, 2015
Last year I spoke with Professor Georg Pingen from Union University in Tennessee. He mentioned that he had a class of students that wanted to study aero wheels on the road. I loved the idea and we sent a set of wheels to the university for testing. The results just came in and I wanted to share how they performed the test and what they found.
The Testing Procedure
Cyclists cycled along a two mile straight stretch of flat road. The bike was fit with the test wheels and an out and back was performed. When the cyclist returned to the beginning, the wheels were swapped and the course was repeated. The order of the wheels was swapped from test to test to limit fatigue error.
Experiment One - FLO 60/90 vs. Alex 200
One student team (Team 3) compared the performance of FLO Cycling aero-wheels. At an average test velocity of roughly 20.5 mph, students found an aero-wheel advantage of approximately 15W with 95% uncertainty bounds of 14.96W±4.56W. Utilizing the equation relating velocity to power (P=Ka*V3+F*V), students were able to use the power savings to predict 40K TT time savings at difference cyclist velocities. The students’ experiments predict a time savings of 1.77 minutes at 20 mph and 1.25 minutes at 30 mph.
|Team 3 on the Course|
Experiment Two - Front FLO 60 vs. Standard Front Wheel
One student team (Team 4) compared the performance of only the front FLO 60 against standard OE front wheels. The goal of the study was to determine if the front wheel makes a larger aerodynamic difference than the rear wheel, as often noted in the cycling literature. At an average test velocity of roughly 19.8 mph, students found an aero-wheel advantage of approximately 7.25W with 95% uncertainty bounds of 7.25W±5.89W. The average time savings over a 40K time-trial at that velocity was calculated by the students as approximately 50 seconds. This savings is roughly half of the savings obtained by using both wheels, thus not indicating larger savings from the front wheel.
Thanks to Union University
I love this stuff. I think it's great that Professor Pingen has allowed the students to learn by testing products in the real world. I want to thank Professor Pingen and all the students who were involved in the testing. Great work!
February 11, 2015
Order 18 - All of the Details!
It's our first order of 2015! Order 18 will begin Thursday, February 12 at 10:00 a.m. PST. We will be selling FLO 30s, 60s, 90s, DISCS, and FLO 30 rims.
Every wheel purchased within the first hour will receive a FREE Silca Valve Extender (FLO 60s and 90s) or a free Continental tube (FLO 30s and DISCS). The best way to get ready for Order 18 is to read the "General Information" and FAQ below. We can't thank you enough for your support and patience. Order 18 was slightly delayed due to all of the issues happening at the port in LA. This morning we received good news that our container should be arriving next week. If you have any questions about Order 18 please let us know.
- Order 18 begins February 12, 2015 at 10:00 a.m. PST. Access the store here. You will need a store account to check out. We recommend creating your account here before the order starts to save time.
- On February 12, 2015 the "Store" page will feature a countdown timer. When it hits 00:00:00:00, refresh your page to begin shopping.
- 700 wheels will be available during Order 18.
- We will have FLO 30s, 60s, 90s, DISCS, and FLO 30 rims available.
- Wheels are estimated to ship by February 27.
- There are currently 1,619 people signed up for Order 18.
- All sales are on a first-come-first-served basis. We are working hard to eventually have stock. For more information, please read this blog article.
- Orders tend to sell out quickly. Popular wheels can sell in five minutes. We suggest being online at 9:55 a.m. PDT if you are interested in buying wheels. Please know there is no pressure to buy, we just want to be honest.
- Order 19 is scheduled to take place in late March/early April 2015 and is estimated to have approximately 700 wheels.
- You are not guaranteed a wheel when adding it to the cart. You must check out to confirm your order.
Questions About Order 18
Q1. How and where do I place my order?
A1. The store opens at 10:00 a.m. PST. On the morning of the order, the store page will have a countdown timer on it. When the count down timer hits 00:00:00:00, refresh your page to access the store and begin shopping!
Note* You will need to create an account to shop in our online store. We highly recommend creating an account before next Thursday to save time during Order 18. You can create your account here.
Q2. Do we have live, up-to-date inventory on our site?
A2. That’s sort of a yes and no question. When you select the product you will see how many are available under the “Bearings or Bearing/Build” pull down menus (The “Sticker Color” pull down does not show how many wheels are in stock). If there is one left and you add it to your cart it does not mean you have secured the wheel. You must make it all the way through the cart before the wheel is yours. If someone else has bought the wheel in that amount of time, you will receive an out of stock warning when you hit the confirm order button.
Q3. My page is really slow. What should I do? (We hope this doesn’t happen!)
A3. We have done all we can to beef up the server to prevent crashing. That said, there are no guarantees. When you click to add a wheel to your cart it may take a second or two to load. Please do NOT hit the "Add to Cart" button multiple times. If you do, you will add more than one wheel to your shopping cart. If there are any technical difficulties during the sale, please be patient, we will be working to correct them as soon as humanly possible. If your page is slow after hitting “confirm order” PLEASE DO NOT HIT REFRESH or your card may be charged twice. If you do hit refresh by mistake and are double charged, please let us know and we will be sure to refund your second order.
Q4. Can you provide more information about the Silca Valve Extenders and Continental Tubes?
A4. A FREE Silca Valve extender will be given for each FLO 60 and 90 and a free tube will be given for each FLO 30 and FLO DISC. Please see the pictures below.
Q5. When will the wheels ship to me?
A5. Wheels are estimated to ship by February 27.
Q6. How much are ceramic bearings?
A6 Ceramic wheels are an additional $100 per wheel. Ceramic bearings support our Bike for a Kid Program and have excellent durability. Learn more about our Bike for a Kid Program.
Q7. Do you offer Shimano 11 speed hub bodies?
A7. All of our wheels ship with 9/10/11 speed-compatible hub bodies. The wheels also ship with 10 speed spacers for people running 9 or 10 speed cassettes.
Q8. What payment methods do you accept?
A8. We accept Visa, MasterCard, American Express, and Discover. We do not accept PayPal.
We hope that this answers your questions about the upcoming Order. If we have left anything out please let us know.
Thanks again for your patience and support.
Jon and Chris
February 1, 2015
Posted by FLO Cycling at Sunday, February 01, 2015 Labels: Aerodynamics , FLO Research & Development , Tire Study
The wind direction sensor I have been waiting for has finally arrived from Germany. It's made by a company called Lufft and is accurate to +/- 1 degree. There are a number of wind direction options but most fall into the +/- 5 degree range. Since the yaw angle spread on a bike is narrow, the accuracy is very important.
I also took a look at my old wooden mounting system and noticed the supports had cracked. After listening to my brother's advice I decided to replace the support with aluminum. In the process I ended up rebuilding the entire support structure from aluminum and I am happy I did. There are a number of improvements.
Here is a picture of the old mount I had built from wood.
The rest of this blog article shows the building of the mount, the mounting and wiring of each of the sensors and finally a test of the wind direction sensor.
I used square aluminum stock in 1 inch and 3/4 inch and then 1 1/2 in aluminum flat bar for the build.
I had to make two 90 degree angles for the main support so I used L brackets. While I have a new welder sitting in my garage, I have no idea how to use it yet.
Here is the unit with the two 90-degree sections completed.
The next step in the process was figuring out how to mount the wind direction sensor. I used the flat bar with a hole drilled in it to hold the sensor. I also used a series of rubber washers to reduce road vibration. In the past I've mounted breadboards to the front of the bike for measurements and have quickly realized that the vibration from the road makes resistors bounce around like popcorn. You can see the rubber washers placed under the mount below.
Here you can see the mount bolted to the main support.
The next step was to build a place to mount the batteries that power the wind direction sensor. The wind direction sensor requires 24v so I need a decent sized battery set up. I placed a piece of flat bar on the main support to house the batteries.
The next step was creating a platform to mount the data logger and some of the sensors. I salvaged part of the old mount for the new one.
With the basic structure finished I had to create support legs that would mount to the front fork. The idea is that the mount will move with the front wheel since we are studying tires. Below you can see the support members that are holding the mount in place.
Then I was ready to start mounting the sensors. First up was the wind direction sensor. Below you can see it mounted out front where the air flow will be as clean as possible.
Next up was the wind speed sensor. This was mounted behind and above the wind direction sensor.
The Onset data logger was next. I used a couple of mounting screws to mount the unit above the handle bars. This way I can see if there are any warning lights going off.
Now to mount the batteries. Yes, that is duct tape. I thought about the best way to mount these and to be honest this was the best way I could think of. The Gorilla tape I used is the toughest tape I've ever seen. The batteries aren't going anywhere.
The wind speed sensor and the temperature sensor came with long cords and some additional hardware. I found an old project box and modified it to hold the cables.
This cleaned up the front of the bike a lot and also gave me a place to enclose the temperature sensor. I wanted to keep it out of the sun to prevent shifts in temperature as I moved in an out of the sunlight.
With the cover placed on the box I think you'll agree things look pretty clean.
The barometric pressure sensor came with a short cable and was housed in a small box. I used double-sided tape to mount this on top of the project box. I also mounted the 4-20mA input on top of the project box. The wind direction sensor has a 4-20mA output and the input receives the info and converts it for storage in the data logger.
The final step was wiring the wind direction sensor to the battery and the 4-20mA input. The first go around I kept the wires a bit long incase there was a problem.
With the wind direction sensor wired up it was time to test it. I had not tested it since it arrived and was really hoping that it would work since I had spent so much time getting everything ready. Luckily for me it did. Below you can see the 4-20mA signal for various angles. When you see the jumps from 4-20 this is were the sensor is going from 0-359 or 359-0 degrees. To eliminate this when riding I will end up mounting the sensor so south is pointing forward. This will give me a range centered around 12mA instead of the break at four and 20. While it won't change the results, the graph will be a little easier on the eyes.
That's it for today. Now it's time to get this beast out on the road. For the first couple of days I plan on staying close to home. While I trust my carpentry skills, I am not sure I won't get chased off the road for being the biggest nerd in Las Vegas =].