SB20 - Power Supply Failure

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The SB20 uses a 24 Volt DC 6 Amp power supply brick to power the bike and its internal components.

When the power supply fails you can experience:

  1. A completely dead bike. No resistance, no shifting and no wireless connections to any app. Nothing.
  2. Resistance that drops suddenly when switching to a bigger gear or going up a steep hill in Zwift.
  3. Intermittent and random communication dropouts. 


Why does the Power Supply Fail?

The original power supply was probably undersized. Instead of 6 amps, it should have been 10 amps. Using the built-in USB ports can also overload the power supply.

How to Fix

First! Check the connector going into the back of the bike. It can shake loose. Make sure it is fully inserted,

Worst Case 😤: Your Power Brick has failed. Fixing is easy. Get a replacement from Amazon. You can always return it, if it does not fix your problem.

You want a 24 VDC 10 amp power supply with standard DC connector.  Here are some examples:

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It appears that Stages no longer sells replacement power supplies.

See Also

Broken shifters can also cause the SB20 appear dead and not startup properly.  See SB20 - Shifter Failure.

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