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Showing posts from October, 2023

Indoor Bike Improvement #6 - Better Internet Connections

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6 of 10 - Better Internet Connections Zwift leverages wireless connections that include a mix of Bluetooth, Ant+ and WiFi. They tend to be concentrated in the busy 2.4 GHz wireless frequency band. As we will see below, it's a good idea to move these connections to the less crowded 5 GHz band. Overcrowding in the 2.4 GHz band causes data dropouts, decreased performance and failed connections. Bluetooth and Ant+ use the 2.4 GHz band. WiFi ( to and from the Internet ) can use 2.4 GHz or 5 GHz depending on the device. The SB20 bike and HRMs use multiple Bluetooth and Ant+ connections. Zwift Play controllers use one Bluetooth connection per controller. All in the 2.4 GHz band. This is not a big concern since the volume of data transferred by these devices is minimal. All these devices combined transmit only a few thousand bytes per second.  In contrast, the Zwift App and the Zwift Companion app can transfer millions of bytes per second. Performance gains can generally be found around th

Indoor Bike Improvement #5 - Better Fitting Zwift Play Controller

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5 OF 10 -  ZWIFT PLAY CONTROLLER UPGRADE I like the Zwift Play Controllers . Steering buttons are a nice diversion on a long ride. The dedicated power-up button is always appreciated in sprints.  Braking is surprisingly useful when trying to avoid a zapping fence on downhills. The Fit I found the controller's fit to be uninspiring. The sharp curve on my indoor bike handlebars allows for quite a bit of up/down and side-to-side movement. This is basically a Zwift design issue. The controllers appear to be optimized for deep drop bars rather than the SB20's tightly curved and flared gravel bike-style handlebars. EXPERIMENTS I experimented with various DIY foam inserts - including the shims provided by Zwift. None did much to reduce movement. “Mushy” is how I would describe most button presses . EPOXY SHIM I created a rigid epoxy shim to get better contact between the Zwift controller and my bike's handlebars. Here's what I did: 1. A shim is moulded using epoxy putty. Yo

Indoor Bike Improvement #4 - Improved Shifting

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 4 of 10 - Better Shift Buttons The SB20 indoor bike has OK-ish shift buttons.  IMHO: The blip buttons under the handlebar tape are fine. The brake lever buttons are  mediocre.    Brake Lever Buttons There are 3 programmable shift buttons under the hoods on each brake level. I find they lack tactile feedback. You can't be sure if a button was pressed by feel alone. Also: The buttons on each lever can be difficult to distinguish - particularly in an intense sprint. Here are my modifications: 1. To address tactile feedback issues, I made cutouts in the brake hoods with a X-acto knife.   2.  I extended the buttons with J&B Epoxy putty. Each button has a different shape: round, pointed and flat . I can now identify buttons by feel. 3. I replaced the hoods and painted each button a different colour to make them visually distinct. The result is literally a "worst-to-first" transformation. The buttons now trigger with 100% reliably. It is also much easier to press the in

Indoor Bike Improvement #3 - On/Off switch & Wireless Charger

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3 of 10 - On/Off Switch  3 years ago, the SB20 firmware was rapidly evolving - with lots of bugs. We were all beta testers in 2020.  Powering the bike off and then on was commonplace.   One of the first modifications I made was an on/off switch.   I put my switch on the bike-side of the SB20 power brick. This means power is interrupted immediately when the switch is turned off.  The situation is a little different with a remote or physical switch at a wall receptacle . These switches work fine but you must wait several seconds when powering off. T he SB20 power brick must drain sufficiently for the SB20 to reset.  Good Digital Hygiene in 2023 I remain a fan of powering on my indoor bike before each riding session. This includes restarting all of the apps I use. With no error display or indicator lights, it is impossible to tell if the SB20 is healthy. Not what I want to worry about before a big event. Version 1 The first version was a plastic tab with a push button switch that

Indoor Bike Improvement #2 - USB Upgrade

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 2 of 10 - Improved USB Power  The SB20 smart bike was introduced 4 years ago with a pair of built-in USB-A ports. The intent was to give you USB power for phone charging or adding a tablet. The total power for both ports is 5 watts (2.5 watts for each port ). Welcome to late 2023 . USB at 2.5 watts will not charge many devices. An iPad can actually discharge if plugged into to a built-in port. What's Inside? Beneath the SB20's phone tray is a triangular circuit board for a switching power supply.  It takes 24 volts from the bike's main power brick and converts it to three 5 volt USB outputs.  Extra USB port? Wait a minute. The SB20 has two built-in USB ports. Why the extra USB output?   The beefy power supply circuit board suggests that Stages had plans for an additional device. My guess: the SB20 was supposed to have a screen for gear display. It was likely deleted early in the product development lifecycle.  For those who want to optimize SB20 power consumption, yo

Indoor Bike Improvement #1 - Multiple Displays

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 I have been riding a Stages SB20 Smart Bike for 3 years. I've made some improvements. Here they are. 1 of 10 - Multiple Displays  1. The SB20 bike comes with a spring loaded holder for single phone or tablet. The problem is: this bike needs a separate screen for showing the virtual bike gear. As a life-long bike sprinter, I know that picking the correct gear for a final sprint is critical. As such, I decided on a dedicated screen for gear display along side the app primary app like Zwift. 2. I built this dual-display rack from aluminum c-channel bars available from any Home Depot.  It snaps in to the built-in holder and holds a pair of iPads.  Each piece is cut, filed and polished by hand. Rubber weather stripping inside each channel provided cushioning. 3.  The aluminum pieces are notched so they fit the SB20 holder. An additional aluminium bar is added to between the displays 4.  The SB20's spring clip was modified to snap into the upper c-channel. This makes it easier to

Indoor Riding - ANT+ and Bluetooth

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ANT+ and Bluetooth are essential wireless technologies that enable indoor cycling. What do they do? How are they different? Why should you care? Assumptions: In this post, I use the term indoor bike to mean smart bike or trainer .  I own a Stages SB20 Smart Bike and use it in my examples.  Protocols ANT+ and Bluetooth are  protocols  that facilitate the transfer of data between apps and devices. In this context, they are like spoken languages . ANT+ is like  English and Bluetooth  is like  French . Both communicate similar information using different verbs, nouns and ways of speaking. ANT+ was introduced nearly 20 years ago to support monitoring of data from devices like heart rate monitors (HRMs) and bike sensors. Since then it has been extended to control and monitor fitness machines including  indoor bikes . Bluetooth  was introduced around the same time to support things like handsfree phone headsets. It was updated from 2010 to 2017 to support heart rate monitors, bike se

Stages SB20 - Measuring Torque Against Factory Specifications

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Torque Measurement I previously documented how to compare SB20 power meters with a set of calibrated pedals. It gives you a good indication of how your power meters compare in actual riding scenarios.   This test  statically measures  torque with a pair of fixed weights. It tells you if your power meters meet factory specifications . This test does not provide the full calibration that you can perform with Garmin or Favero pedals. You can't change  offset  or slope parameters to get the Stages PM measure correctly in the future. Basic Testing Procedure The basic method involves two ( big ) steps: 1. P osition the cranks horizontally to get raw measurements produced by hanging 25 lb weights from each crank. 2. Use a spreadsheet to process raw measurements and get an average reading for both cranks. Compare these readings against expected values  (t he list of expected values is shown later in this post ). The test setup looks like this: With equal weights on each side, cranks can

Stages SB20 - Comparing Stages Power Meters with Garmin Rally Pedals

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"Calibration by Comparison "  Procedure Stages doesn't officially support end-user calibration. The following procedure can be used to validate accuracy. It confirms that your PMs are working properly in real riding scenarios.  Here's a summary (sorry -  I wish it were simpler 😔 ): 1. Calibrate another power meter . In my case,  Garmin Rally pedals. 2. Run tests to compare the Stages PM against the calibrated PM  in an actual ride or event . 3. If Stages PM readings are incorrect, change the crank length to compensate ( more on this later ). 4. Repeat Steps 2 and 3 until the Stages PM gives readings that match the  calibrated PM . Calibrating Reference Power Meter - a Garmin PM   Garmin Rally pedals support true "calibration": You position the cranks horizontally and then directly measure the twisting force created by hanging a known weight from the pedal. If a pedal is reading high or low, you can adjust the "offset" so it measures the expecte

Comparing Power Meters using a Spreadsheet

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My Stages SB20 Smart Bike has crank power meters.  I routinely compare them with readings from my Garmin Rally Pedals.   Here's how I do it. Add Gamin Pedals Mount Garmin pedals on the SB20 Smart Bike. This means two  independent  power meter systems are available to simultaneously measure the same activity. Prepare an Activity You can use Zwift to do a free ride, race or structured workout (or consider using a advanced structured workout app like TrainerDay ).  Configure Zwift to use the Stages Bike for Resistance (formerly Controllable ). Use the Stages PM as the Power Source and for Cadence . Tip: Also use an  HRM . Heart rate data helps you synchronize metrics in a later step.     Get a Second Opinion Use another app or device to simultaneously record your Zwift Activity.  I use a Garmin computer to record activities on the Stages Bike.  It is configured to use the Garmin Pedals for Power and Cadence . It also gets heart rate data from the same HRM used in the previous