Pink Molly Lighted Cruiser Bike




Introduction: Pink Molly Lighted Cruiser Bike

About: Dan Goldwater is a co-founder of Instructables. Currently he operates MonkeyLectric where he develops revolutionary bike lighting products.

Turn your cruiser bike into a night-time flyer!  We put 10 feet of form-fitted LED light strips onto the Pink Molly 3-speed cruiser bike.

To do this build you only need basic soldering and wiring skills.

Our own beloved Molly (the exact bike shown in the photos) is currently for sale for $750.  This is the exact bike shown in the photos, it was also featured on Daily Planet on Dec 9, 2008 and in our MonkeyLectric video.  Very good condition with little use.  Base bike is a Haro with 3-speed shimano coaster brake.  Email info-at-MonkeyLectric-dot-com if you are interested in purchasing it.

This project is brought to you by MonkeyLectric and the Monkey Light bike light

Step 1: What You Need

  • Flexible waterproof LED light strips.  You can get these from Adafruit or you can find lots more on ebay by searching for 'rgb led flex strip'.  make sure you get ones with a durable rubber cover or coating.
  • 12V battery.  You can use a small sealed-lead-acid (try or, or 10 rechargeable AA's.  You can get a 10xAA holder from part number 12BH310
  • Optional LED lighting controller.  With just the LED strip you can have any of 7 solid colors.  if you add a controller you can do tons of changing patterns.  Search ebay (or google) for '12v rgb led strip controller' and you will find lots of them.
  • Under-seat bike bag to hold the battery
  • 4x22 gauge stranded wire, about 15 feet.  I got this from
  • double-side foam tape (only a little if your strips already have a sticky-backing.  otherwise you need enough for the length of strip you have)
  • hot-melt glue and glue gun

Step 2: Measure Strips and Wires

Figure out where you want your LED strips.  Do a test fit of the strips to get the length and positioning right.  Also start thinking about where you will route the wires.

The Pink Molly uses 3 separately cut pieces of LED strip:  one piece for the front fender, one for the rear fender, and a 3rd piece goes the length of the frame.

I put my battery under the seat in a standard under-seat-bag.  The wires from the strips need to get to the battery also, so measure that out.

Step 3: Attach the Wire to the Flex Strips

There are a couple of styles of waterproof flex strips out there.  You need to solder your 4x22 wire to the 4 terminals on the flex strip. 
  • For a great in-depth tutorial on this check Adafruit.  The summary:
  • Cut your flex strip into the final lengths.  The strip normally has marks on it where it can be cut, about every 4 inches.
  • Cut off the rubber at the end of the strip to get to the solder pads.  be very careful!  if the rubber sticks to the strip, you can heat it with a hot-air gun to weaken it.
  • Solder the 4x22 wire to the strip.
  • Make this connection durable again.  Hot-melt glue works well for this, just cover it all in a blob of glue.  When you are done the connection should be less flexible than either the wire or the strip, you don't want the connection itself to get bent.

Step 4: Prep the Frame

Remove the 2 wheels

Prop the bike upside-down

Clean the frame with alcohol so the strip will stick permanently

Step 5: Drill Wire Holes If Needed

Lay out the strips and wires the way they will go.  

On the front fender I drilled a hole for the wire to get out near the head-tube.

On the rear fender I drilled a hole for the wire to get out by the rear stays.

Step 6: Start Sticking!

stick down the strips.

Start at one end.  Peel off and stick only 1 foot at a time.  Work your way to the other end.

Rear fender:  the hole for the wire is not at the end of the fender, so the wire does a U-turn at the end of the fender.  The wire inside the fender is hot-glued to the fender so it doesn't flop around.

Wrap the wire with thick fabric tape where it goes through the metal fender, so it doesn't get cut.

Step 7: Keep Sticking!

The frame strip goes right down the center.  it curls around the bottom bracket and goes all the way up the back to the seat-post.

The frame is a bit lumpy at the bottom bracket.  I didn't want any gaps under the strip to improve durability, so along the bumpy area i first put down a strip of double-sided foam tape.

Step 8: Route the Cables

check the photos for photo-note details

Step 9: Battery Connection

If you got a RGB controller it normally will have screw terminals for the battery and for the wires to the LEDs.  If you aren't using a controller you can just use wire nuts to attach the wires to the battery. 

Each RGB strip has 4 wires:
  • Positive
  • Red ground
  • Green ground
  • Blue ground
Without a controller you can make 7 colors by mixing and matching red, green and blue. 

When i'm riding i put a strap around the batteries so they don't bounce out of the holder.

Step 10: Done!

now go have fun.

1 Person Made This Project!


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Reply 12 years ago on Introduction

3 or 4 hours i think.


12 years ago on Introduction

Good basic idea.
But the strips inside fenders? Not so much I think. They are not practical (they get dirty for sure) and light effect is questionable. Better idea would be run strips inside rims and use brush contact from motor to juice them.

I can see that you have instaled monkey lights. I won 1pc here and me and my friends like it very much (I just need to get second piece to balance my wheel and get better effect at lower speeds)

but this gets me inspired! thanks, I'm going to do my version :-)
instructable soon


Reply 12 years ago on Introduction

yes, but you need to move then if you want the light effect. A 9V battery works wonders.