I recently got an old used Huffy eco terra bike with a handlebar computer that doesn't work. Can someone tell me how it's powered and possibly why it doesn't work.

  • 1
    Is there a brand and model on the computer ? You'll probably want to locate a user manual for setting the clock and wheelsize.
    – Criggie
    Oct 27, 2021 at 2:53
  • 3
    "Doesn't work" is pretty broad. Does the display show anything (when you press a button if not all the time)? When you press buttons, do things happen? Is there a sensor beside the wheel? If so, does it have a wire running from the sensor by the wheel? Is there a magnet attached to the spokes?
    – mattnz
    Oct 27, 2021 at 3:01

1 Answer 1


The Huffey Eco Terra is an 18 speed MTB, and has no electronics. So your bike computer is a later part, unlike an ebike where the electronics are integrated.

Start with the easy things.

  1. If it has a cracked LCD, recycle it. Not worth bothering when these units are cheap to buy new.
  2. Check the battery, and replace if required. You should see characters on screen. The battery is probably a common CR2032, though some older units have a small 12V battery. Also look for corrosion when the back is open.
  3. Check that there is a pickup unit on the frame, probably the front fork. It may be wired, or wireless (and require its own battery)
  4. Check there is a sensor magnet on one front-wheel spoke, which passes very-near the sensor.

You can wave a normal magnet near the sensor and should see the display account for forward motion.

From there, tell us what does and doesn't work and we'll refine things.

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