Motorcycle Gear Indicator

This indicator has been tested and has been fully operational on my 1999 Bandit 1200 for 4 years. It operates on those motorcycles that use the neutral detector switch, part number 37720-48B00. Currently, I have found the following bikes use this switch:

    1997-2000 Suzuki Bandit 1200

    1996-1999 Bandit 600

Early Katanas share the Bandit engine and also have this switch. For later Bandits (2nd generation), the part number changes but the engine and trans are almost identical. There may also be a fit here. The Suzuki 6 gear switch is $50 from www.ronayers.com so make sure before you buy.

Complexity: You should have knowledge of electrical circuits if you plan to vary any of the resistor values in the circuit. 9-10 milliamps are supplied to the LEDs in this circuit as bright LEDs use more current than the conventional 3mA variety. Beyond that, if you're mechanically handy and can solder, go ahead. The installation took an afternoon for me. The circuit design and testing took another day but it's been done here for you.

Parts:

Other: Solder, circuit board, breadboard (to verify operation), electrical tape

Tools: Philips screwdriver, allen wrench (5mm?), assorted drill bits and drill, tape measure, soldering iron

Operation:

The circuit identifies the gear you are in by lighting a count of LEDs. This is better than just lighting one LED per gear as you cannot identify what gear at a quick glance. you can, however, quickly identify three lit LEDs as third gear. One LED for 1st gear, two for second and so on until 5th, where all go out.

Optional 6th gear - When a Bandit 600 is used, add one more circuit and LED. this would identify 5 gears and go out on 6th.

Superbright LEDs are recommended for daylight viewing

Tech:

Selecting a gear other than high gear will short the transistor's base to ground through a current limiting resistor. This causes current to flow through LED circuit and lights the LED for that gear. If also higher than 1st gear, current will flow through the switching diode(s) to provide a ground for all lower gears, lighting that gear as well.

Circuit:

Installation (read first as it is not in order):

1. Gear Switch: Install the gear selector switch from Suzuki on the transmission by removing the chain sprocket cover and locating the switch near the bottom of the trans. Removal is by two philips head screws. Be sure not to lost the o-ring. The original neutral indicator should fit just as the original. This modification preserves the original neutral light.

2. Gear wire ID and routing: There are six wires - one for each gear. Use an ohmmeter to identify them. Change gear and rotate the tire forward to fully engage the transmission. This will provide a good ground on the switch. Identify the color code and gear and write them down. For 5-speeds, fifth and six are not required. Include 5th for 6-speeds. Route the wires safely to the circuit. Allow slack for the triple tree.

3. Circuit build and location: Build the circuit on a breadboard to test it (recommended) and to be sure that you are applying the proper current to the LEDs you've selected. Cheap circuit boards are available at Radio Shack. Only a solder iron and some wire is required.  I located the circuit board within the wire bundle behind the headlight on my Bandit. This protects it from the elements.

Here's a fuzzy picture of my circuit board:

4. Power: The Bandit provides switched power near the circuit location. Use this or tap ignition voltage (key on) by some other means. Grounding is provided solely by the gear selector switch.

5. Dash Cutting: Remove the dash and drill four (5-speed) or 5 (6-speed) holes in the top of the dash. Start with a very small bit so that the hole can be started. No room for error here so I recommend placing tape on the top and using a tape measure to locate the center point of each hole to be drilled. Once drilled, increase bit size to the best fit for the LEDs. Drill and done. Alternatively, locate it anywhere you like. I originally created a 7-segment display but there was no good location.

6. Grounding: There are essentially 2 circuits in play for each LED. The switching circuit enables the LED circuit. Grounding is through the trans switch for the former. For the LED circuit (latter), you need to connect all LED cathodes together and ground them to the bike's frame.

7. Dash completion: Connect a wire to each LED anode and with the LEDs inserted into the dash, provide a sealant to keep water out of the dash. No matter how tight the LED fit, water can get in there. I used non-silicone caulk. Important: The LEDs will interfere elsewhere in the dash (other dash lamps) so you must apply a "light blocker" like black electrical tape to keep the LED light shining only through the LEDs. The caulk also helps but you'll see what I mean.

8. Connect the LEDs and switch to the circuit and test it with the bike on the center stand. Don't connect them backwards as I first did!

9. Protect the circuit board by coating it with epoxy or wrapping it in electrical tape. I have found by using tape that I only get a problem when I wash the bike and some pressurized water gets in the dash area. First gear showed in neutral for a week until the board dried. I should have taped it better.

Slap yourself on the back - you're done!!!

More fuzzy Pictures:

Neutral                                                      

First Gear                                                    

Second Gear

                              Third Gear                                                   

Fourth Gear                                                

 Fifth (lights Out)