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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 ...