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

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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