Introduction: Bed Liner Bike Frame

In this instructable I will walk you through the steps I followed to paint my old trek mountain bike with roll on truck bed liner.

Why bed liner? I was looking for a way to keep my bike from gradually getting chipped when I locked it up everyday, crashed it or generally just treated it roughly. These chips while aesthetically unpleasing can also cause a steel bike to rust if left unattended, reducing the life of your frame, as is the case with the bike I will be working on in this instructable. I recognize that I could treat it better, be more gentle when I load it in the bike rack, and quickly repaint any chipped areas with clear nail polish, but I didn't want to. I wanted to find a more bulletproof way to solve the problem.

Has this been done before? Yes, of course, but to my knowledge this is the first one done with Monstaliner. Here are a few examples I found while researching this project: Here (scroll down for pics), here and some motorcycles here.

Note: this is the first time I have ever painted a bike so I made my fair share of mistakes, which I was expecting. I am painting by backup commuter bike, the beater that I use when my road-bike is in the shop or when there is foul weather, so I was not incredibly concerned about getting a perfect paint job. My objective was to give it my best effort, collect all my lessons learned, and determine it I should apply this same coating to my much nicer road-bike down the road.

Step 1: Bed Liners

For this instructable I used Monstaliner tintable bed liner.

There are a silly number of options when it comes to DIY truck bed liners : Hurculiner, Rhinoliner, Raptor liner... the list goes on and on. These were the factors that I was using to narrow my search and eventually decide on Monstaliner.

1. Robustness above all. I wanted the highest quality and the thickest liner I could get. I was covering a rather small surface area so I was willing to use a premium brand.

  • This ruled out the cheap rattle can options

2. Surface texture. This is the big one. When I wipe out on my bike, I want the only thing abrading off by skin to be the asfault, I don't want my bike frame getting in on the action. The surface could not be rough.

  • This honed me in on Monstaliner very quickly, first because they don't add any tiny chunks of rubber to give their liner surface texture (a la sandpaper) something they brag about in their comparison page; at the bottom of this page they also have test panels comparing their liner to the other top brands which was useful to reference.
  • Monstaliner also sent me 5 free test panels with different colors of their liners which basically sealed the deal for me.

3. Color. This was a nice to have.

  • I had already selected Monstaliner at this point, so their huge number of color options were just icing on the cake. Warning: a few of their colors are lead based.

4. UV Stabilized, If I am going to get some bright flashy color I don't want it fading.

  • I have read that some other liners require an additional coating to provide UV protection.
  • Monstaliner is UV stabilized so no fading.

Here is a Monstaliners video describing their tinatable liner.

Note: For my bike I did not do the re-roll to develop the final texture that they describe in the video, because I wanted a smoother finish.

Here is a video of a company spraying Monstaliner on a Land Cruiser

Spray-on VS. Roll-on

If you have access to an air compressor and can set up a paint booth I would recommend spraying on the Monstaliner as opposed to rolling on. Spray-on will result in a more uniform coat, you will not have to fiddle with sponges to get into all the nooks and crannies on a bike frame and you are less likely to miss or undercoat hard to reach areas. You will need some additional supplies if you plan on doing spray-on:

  1. A Paint booth, (plastic sheets and a way to hang them, just so you can avoid over spray)
  2. Shutz Gun
  3. Respirator with appropriate filter (Always make sure you are using the right filters)
  4. Additional MEK to thin the Monstaliner
  5. Air compressor

However, if you don't have all these extra supplies, as was my case, you can still end up with a good looking paint job it will just take more care to get the coat uniform and more time to apply.

How much does it weigh?

I estimate that it added about 1.5 lbs to my frame, because I didn't have access to an appropriate scale to weigh the can before and after application, this is only an estimate. I know that there are many cyclists who aim to minimize the weight of their bike, as you can tell from the 6 pound chain lock wrapped around my seat post that I am not that type of cyclist and if you are, then this mod is probably not for you.

Step 2: Master List of Materials

Bike Disassembly

  • Metric Allen keys
  • Crank-puller
  • Bottom bracket tool
  • Chain breaker
  • Ratchet with 14mm socket

Fame Prep

  • 120-180 Grit sandpaper
  • MEK Solvent (or MEK substitute)
  • Rags
  • Soap and water


  • 1 Quart tintable Monstaliner
  • Pouch of catalyst
  • 2" Mini Roller Kit + Foam Block
  • Quart Tint - 2 Ounce [Select Color]
  • Drill
  • Power drill mixing paddle
  • Paint mixing stick
  • String (to hang bike)
  • Scissors (to cut the sponges and string)
  • Drop-cloth, tarp or plastic sheet.
  • Painters tape
  • Paint tray
  • Rags

Post Painting Finish

  • Spray bottle

Bike Reassembly

  • Loctite 242 (Blue)
  • Grease
  • Knife
  • Cable cutter (Optional)
  • Plus the same tools as disassembly

Chain ring change (Optional)

  • Pin Spanner wrench

Step 3: Strip Down the Bike

If you already know how to strip a bike down to its frame and fork than you can skip this step. However, if you have never done this before, as was the case of me, keep reading.

First the tools, you will need the following:

  1. Metric Allen key set
  2. 14mm socket and ratchet
  3. Crack-puller
  4. Bottom bracket tool.
  5. Bike chain tool (unless you chain has a quick link)

Note: Before this instructable I didn't know what a crank puller or a bottom bracket tool looked like. So I went to Park Tool's Repair Help and Education section to learn the basics, then I took my bike to my local bike shop and asked my bike mechanic if he could help me pick out the tools (specifically the crank puller and bottom bracket tool) that would work for my specific bike.

  1. Remove all the accessories and sticker (Lights, locks, racks, kick-stands...)
  2. Remove the chain, either with a bike chain tool or if you have a quick link un-link it with your hands, or a pair of pliers if it is stuck. (Note: Quick link chains are amazing)
  3. Remove your front derailleur with your Allen key
  4. Remove you rear derailleur with your Allen key
  5. Remove the front and rear breaks.
  6. Remove the crank arms and bottom bracket. This part always intimidated me, but after watching this youtube video demonstrating the process it was a breeze.
  7. Remove all cable housings.
  8. Lastly remove the handlebars with all the shift and brake cables, and the wheels.

Step 4: Prepare Bike Frame

Before we can apply our first coat of Monstaliner to the bike we need to do the following:

  1. Clean the bike with soap and water removing any gunk, sticker residue, and dirt.
  2. Sand the entire bike frame with 120-180 grit sand paper getting rid of all the glossy finish.
  3. Clean the entire bike with M.E.K. solvent. I couldn't find MEK locally so, I used the substitute that they had at my local Ace hardware. (Just make sure it says MEK on the bottle somewhere)


  1. 4 Sheets of 120-180 grit sandpaper
  2. Anti-particulate mask
  3. MEK, or equivalent
  4. Soap and water

Note: My bike had one of the those thick protective stickers over the chain stay to keep the paint from getting scratched by the chain (won't need that any more). I couldn't figure out a good way to get it off, pealing didn't work, and I ended up going at it for an hour alternating between 120 grit sandpaper and MEK, it was not fun. If you know a better way to do this please post in the comments. Thanks

From the Monstaliner Installation Guide

• If your bed has minor rusted areas, Monstaliner can be applied directly over rust. Proceed with taping/masking in Step 6.

This is good, so I will be applying the Monstaliner directly over the rusted patches on my bike, after sanding and cleaning them of course.

Step 5: Jigging and Masking

If you want clean results this is where you want to take your time and do it right.

I made several mistakes here that I will address in my lessons learned section, but here is a rough checklist of items that you want to mask with painters tape, a fastener or a rolled up magazine:

  • Wheel mounts
  • Water bottle cage mounts
  • Guides for all brake and derailleur cable housings
  • Rack and fender mounting points
  • Brake mounts
  • Seat post
  • Bottom bracket (Rolled up magazine works well)

Step 6: Mixing the Monstaliner

Read the correct freaking manual.

The correct instructions for mixing the tintable liner are on the back of Monstaliner's instruction guide and are slightly different that the instructions for their plain black liner in the front of the guide. I started following the instructions for the plain black liner until I realized there was no step to add the 2oz. of green pigment at which point I found the correct instructions on the back of the guide.

Everything turned out fine, even though I added the catalyst before the pigment. I emailed Montaliner and they got back to me and said it was not a problem.

The correct page of the manual that you should reference is pictured above.

A few important notes that are mentioned in the manual but I feel I should reiterate:

  • Use the provided mixing stick to scrape the sides periodically otherwise it will begin to set-up on the walls of the can
  • Wear a hat or bandanna to keep your sweat from dripping in the can. Monstaliner reacts with moisture and a drop of sweat can decrease the pot life.
  • Keep the lid on the can and work out of a paint tray (not provided)

Complete PDF of the manual for reference.

Step 7: First Coat

Make sure you roll straight with firm pressure, and when your using the sponges in the hard to reach places just dab the Monstaliner on don't brush it.

Here is a list of the areas that I did not cover completely in my first coat that you should look out for:

  • Underneath the chain stays
  • Inside the chain stays near the dropouts
  • In between the forks
  • Under the bottom bracket

After you think you have coated the entire bike lay under it (if it is hanging) and you will see all the spots you missed.

Step 8: Second Coat

Coating must be dry to touch with little or no tack under your fingers [before you can apply the second coat]

This will vary greatly based on temperature and humidity. It was nearly 80F when I finished my first coat and it was fairly humid, so my time between coats was very short, about 1 hour, for the tintable liner it can take as long as 4 hours.

You want to only pour small amounts in the paint tray and reserve the rest of the mix in the can with the lid closed. This will keep the mix from thickening up too much, but it will still thicken up as you are applying your second coat. If it gets to think to pour out, which I it likely will, just power mix it with the drill mixer and it will thin out.

Immediately after finishing your second coat you want to remove all of your fasteners and tape that you are using to mask off areas of the bike.

Step 9: Spray Down the Bike

Per the Installation guide you want to lightly spray down the bed liner with water 8-10 hours after the final coat is applied. I finished my last coat at about 10pm, so the next morning before work I sprayed it down.

Note: I left the bike hanging on my back deck for 3 days after painting it because it continued to smell like solvent.

Step 10: Reassemble the Bike

I waited until the following weekend to reassemble the bike because I wanted to make sure the liner was completely dry before wrenching on the frame. (Manual says that complete cure takes 1 week)

The reassembly was fairly straight forward as you can see from the pictures above. I only modified the following

Step 11: (Bonus) Convert to a 1x6 Speed

I took the opportunity to convert my bike to a 1x6 speed by removing the three chain rings and front derailleur and replacing with a single chain ring and a bash guard.

Here are the parts I used:

Here are the references I used:

Explanation of Bolt Circle Diameter (BCD)

1x9 Conversion walk through

Step 12: Lessons Learned

  1. Make a schedule and stick to it. This is the schedule I almost maintained, except my sanding bleed into my painting day and resulted in me cleaning up at 11pm Sunday night.
    • Friday afternoon disassemble the bike
    • Saturday Sand the bike
    • Sunday Paint the bike
    • Monday morning spray the bike down with water
    • Next weekend rebuild the bike
  2. If you can, remove the fork, or at least wrap a string around the gap between the bottom of the head tube and the fork to keep any paint out. For my next paint job I am definitely going to learn how to remove a fork.
  3. Fill brake cable housing guides with a short scrap piece of cable housing that has a string running through it with a stopper knot on one end. When the second coat is done you just need to grab the string and pull the housing out.

Overall I was very pleased with how the bike turned out, although only time will tell how the bed liner holds up. For any of those considering this project I will post an update in a few months on how it is holding up.

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