PedalSmart.blog

If you use Zwift long enough, you have seen the following: Why does my Bike Disappear from Zwift? The SB20 bike can have at most 2 Bluetooth connections. After this limit is exceeded, the bike is not visible to apps like Zwift. Each Stages power meter crank can have at most 2 Bluetooth connections. After this limit is exceeded, the PMs are not visible to apps like Zwift. Sounds easy to manage, right? Not always . The hidden culprits are apps on your phone. It is common for an app controlling something like a TV or speaker, to connect to the SB20 and PM cranks to see what services they provide. To do this kind of "feature interrogation", one of the two available Bluetooth connections will be used. If the app developer is not careful, that connection can be maintained when you open another app.  Here is an example of a feature I recently implemented in my GearView app This simple page lets you check battery levels of all nearby devices before starting a ride.  One click and ...

Let's see how to replace an SB20 smart bike bottom bracket . When to Replace Bad bottom brackets are pretty easy to identify. They will exhibit one or more of the following behaviours: Grinding that feels like sand in the bearing when rotated slowly. Excessive play when pushing the cranks in and out. Wobbling when riding - especially when pushing hard. What is NOT bottom bracket failure Clicking noises.  Instead: Check pedals and look for loose crank bolts. Rubbing noises.  Instead: Look for problems around plastic covers. Noises that get loader as you pedal faster . Instead: Check the flywheel.   Tools Needed Car mechanics can rejoice. You have most of the required tools. Tool Summary: Heat gun for loosening red Loctite that holds drive side bottom bracket fastener (alternative: hair dryer). NLGI #2 automotive bearing grease (alternative: bike bearing grease). 18" or longer torque wrench for tightening bottom bracket when reassembling (Alternative:12" wrench -...

Free Riding is Easy Let's start with the relationship between resistance , cadence and power (watts) when doing an indoor free ride (sometimes called sim mode ). Free riding follows a simple formula:  Power in watts  =   How hard you push   ⨉   How fast you pedal   Your indoor bike offers constant resistance when you stay in the same physical or virtual gear. Pedal at a constant RPM and you get a consistent number of watts. If you then pedal 10% faster, you produce 10% more watts.  Pedal 10% slower, you produce 10% fewer watts. 📣 Free Riding Summary: When simulated riding conditions stay the same, pedalling faster produces more watts. Pedalling slower produces fewer watts. And don't forget: There is one way to go faster in Zwift.  Produce more watts 💪.    If only indoor riding was always this simple... Erg Mode When doing structured workouts, Erg mode is popular. It allows you to produce a desired number of watts whether y...

In my last post, I described why Erg mode is not always optimal:   What is Erg Mode and Why Can it Suck?   In this post, I describe how the Erg mode works on a Stages SB20 Smart Bike .  SB20 Erg Mode The  Stages SB20  bike is different than other smart bikes or a trainer. It uses crank-based power meters and  not flywheel speed  ⨉  resistance  to determine power levels. This simplifies the power calculations but adds some Erg mode wrinkles. A simple  SB20 Erg mode  flowchart looks like this: The SB20 is measures cadence and power at the cranks rather than calculating power based on flywheel resistance and RPM.   On paper, this method should provide a very responsive erg mode. The reality is: it is one of the slowest erg modes to stabilize after cadence and target power changes.   Why so Slow? The Stages power meter cranks send readings to the SB20 processor once a second. Due to limited processing capability in the cranks,...

SB20 Dream Dream provides equally spaced virtual gears across the SB20's Resistance Range .  Define a configuration with 10 gears and you get 10 equally spaced virtual gears. Create 25 gears, and you get 25 equally spaced gears.  How does this compare to traditional 2X gearing with its 2 front chainrings and rear cassette?   Let's find out. What are Virtual Gears? First, let's understand  virtual gears .  How do they differ from an indoor trainer and why are virtual gears often considered better? Smart bikes and trainers expect apps like Zwift to control electronic brake resistance.  This allows the indoor bike to simulate riding conditions like flat or hilly terrain along with different riding surfaces like dirt or asphalt.  Trainers use the attached bike's physical gears to add the resistance that represents the effort needed to move a bike over the simulated terrain.  Smart bikes accomplish the same by simply increasing the ele...

Welcome to 2024 I did 52 bike related posts on PedalSmart.blog in 2023. 40 of these posts apply to the Stages SB20 Smart Bike .  Here are the 5 most popular SB20 posts based on views by my readers . 5. Comparing SB20 with another Power Meter  Many of us are concerned about power meter accuracy. ZwiftPower users can easily do comparisons. Comparing Power Meters with ZwiftPower One Downside: Zwift keeps track of all these comparisons. They may use these tests to disqualify you in the future. For a totally private test, consider:  Comparing Power Meters using a Spreadsheet   4. Top 10 SB20 Modifications and Upgrades Here are the 10 biggest improvements I've made for better indoor riding. My 10 Indoor Bike Improvements   3. Zwift Power Sources What's best way to connect Zwift to the SB20? It depends. How to Pick a Zwift Power Source   2. Measuring SB20 Power Meters  Comparing the SB20 with the power meters is a good first step. But how do you know ...

December 20, 2025 Update: This bug is still present in Zwift Release 1.104.3 Bug Summary: Stages Bike is not listed as Resistance controller when Stages Power Meter is selected for both Power Source and Cadence . History For almost two four years, the  Stages SB20 bike has had an issue connecting to Zwift.   On seemingly random occasions, the  Stages Bike  is not shown as a  Resistance  option on the Paired Devices page. This bug is easy to reproduce on iOS devices (iPads and iPhones) using Bluetooth.  Stages Bike Resistance Bug Before starting, do some pedalling to wake up the Stages Power Meter cranks .   Open the Paired Devices screen. Click Power Source to continue. Select the  Left Crank  for  Power Source . Select the  Left Crank  for  Cadence . Since Left Crank selected for both Power Source and Cadence ,  Stages Bike is not listed. Note: If Stages Bike is listed ,  exit  and...

When doing my 3 month test on Batteries and SB20 Power Meter Accuracy  I did many power meter battery changes. Here are some interesting things I found. Button Cells Stages power meters use CR2032 button cell batteries. Their naming is logical enough.  The first letter for  chemistry : C=Lithium, L=Alkaline and S=Silver, is a bit confusing.      "Mark" Batteries Before Using Them I paint unique markings on all new batteries  before installing them.   I changed batteries from new to old - and back - dozens of times in the past few months. I dropped batteries on the floor more than once. A unique mark lets me distinguish new from old . Easy Battery Removal I stumbled on this Stages battery removal trick:  Push the battery inward , opposite the side contact.  Rejuvenating Battery Contacts My power meters are 3 years old. Its battery contacts have become slightly flattened . Pushing them back to their original position is a delicate but ea...

Today's question: How does battery level affect SB20 power meter measurement? Let's do a deep dive and find out! My Overall Takeaways I recommend battery change interval to be 100-150 hours. Be careful with battery level estimates. Battery levels  do tell  when the battery is healthy (when 90-100%).  Estimates then to drop off after this . Nowadays, I use  BattView   to watch for when my PMs drop below 90%. This corresponds to around 150 hours and is a good time for me to replace my batteries.  Note: You may have different thresholds. If I had a really important indoor event, I would consider replacing batteries if I was near the 150 hour or 90% remaining threshold.  In-Depth Measurements Replaceable Batteries The Stages SB20 power meters have replaceable batteries. An advantage: No degradation of built-in batteries as the power meters age. A disadvantage: No ability to top up batteries to 100% whenever you wish. Battery Life CR2032 button cell b...

In a previous post, I showed how to record data from two power meters and analyze results in a spreadsheet: Comparing Power Meters with a Spreadsheet . Today's post shows how to do power meter comparisons using ZwiftPower - and no spreadsheets 🤓. ZwiftPower Dual Power Meter Analysis Tool The ZwiftPower.com web site has a tool for comparing power meters. It works best with a Zwift activity (race, workout, group ride or whatever) although the method described here lets you compare any FIT activity files from other sites like Rouvy.com or TrainerDay.com .  Note: Comparing power meters is only useful if one or more of the power meters has been calibrated with a torque test . Skip this test and you won't know which power meter is incorrect when differences are found . Comparing SB20 Smart Bike with Garmin Rally Pedals In this example, I use my Stages SB20 smart bike to compare power readings with a set of Garmin Rally pedals.  I do a structured workout where Zwift records pow...

Like many riders, I use the same saddle on both my indoor and outdoor bikes. I had the option to buy a cheaper and heavier version of this 3D printed saddle for indoors. That was nice. Zeus 3D Printed Saddle I bought the $50 nylon frame version for indoors and the lighter $65 full carbon version for outdoors. The outdoor saddle is 2 years old with 12,000 kms and still looks like new. The indoor saddle will likely outlast me.  For the small price difference, I recommend the carbon version. I just wanted to say I paid less for the heavier indoor saddle 🙂. This is the most comfortable saddle I have ever used. That's personal of course. The saddle is average width with wider than normal nose. I had no idea this design was good for me until I tried it. At 165 grams for the outdoor carbon version, it's also the lightest saddle I've owned. For those who care... The Ensolite-like  honeycomb padding is 3D printed.  It is bonded to a carbon fibre or nylon outer frame, depending o...