From the dustbin — my DIY restoration of a $75 Cannondale CAAD4 R4000 frame from Marketplace
Updated: Jun 26
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In early 2023, I was perusing used bicycle listings on Marketplace when I saw an ad for a 1999 Cannondale CAAD4 R4000 frameset in Stars 'n Stripes livery listed for $75. The seller was located about an hour away from me, and there weren't too many details included in the listing other than the fact that it was a 56cm frame and there were no visible dents in the alloy tubing. A few lower-res photos showed the frameset along with a few extra "goodies" that the owner would be throwing in with the sale of the bike -- some old Deda alloy handlebars and seatpost, ITM stem, a 1" to 1 1/8" threadless steerer tube adapter (more on this in a bit...) and an older set of Mavic CXP22 rims laced to Coda hubs, replete with deflated, cracked, 21mm tires.
Bingo. This was just what I was looking for. While most people would view this as trash, I viewed it as an inexpensive entry into my first attempt at a DIY rattlecan repaint and frameset restoration project. I messaged the seller, agreed on a meeting place, and later that afternoon I was driving home with half a bicycle shoved in the backseat.
Not having much use for any of the parts aside from the frameset itself, I soon listed those for sale and within a week had recouped $50 by selling the Mavic wheelset to a gent that was in need of a cheap solution for his indoor trainer. Perhaps unsurprisingly there's not much of a market for low-end, used, alloy cockpit components from the late 90's as I still have the stem, handlebars, and seatpost sitting in my garage. :)
My attention next turned toward the frameset itself, where I soon discovered why the seller had perhaps priced the frameset so low to begin with. As I removed the steerer tube adapter, I found that the steerer tube of the original 1" threadless Time Slice fork had been cut so low that the top of it sat just inside the upper headset bearing. Unfortunately this wasn't disclosed to me at the time of purchase, and the appropriate term for such a fork is "utterly useless" -- for this frame, at least. I'll take the blame for not recognizing this issue when I inspected the frame in person before purchasing, but oh well. Lesson learned. To be fair, even if I had noticed the problem at the time of sale, I probably still would have bought the bike.
Now if my experience buying used bike parts from sellers on eBay has taught me anything over the years, it's that when life gives people lemons, those people go right ahead and list them on eBay. Please don't do that.
In the case of the fork, however, everything about it was flawless aside from the fact that the steerer tube was too short for my frame. I listed the fork on eBay with explicitly clear warnings about the steerer tube length as well as accompanying photos, and within a couple days someone bought it for $40.
Sweet. I had now made a few extra bucks on this frame. But that would be the end of that. Spoiler alert, but everything costs me money from here on out.
The process of paint
I'll start off this section by saying that before I took on this project, I didn't know the first thing about spray painting a bike. The only thing I knew is that the interwebs told me a good result cannot be achieved with a spray can. That being said, you can find a few good resources for DIY spray painting a frame if you look hard enough (see here, for example).
My strategy for the DIY repaint was the following:
Strip off the old paint with aircraft paint remover
Sand and prep the frame for primer
Prime the frame (2 light coats, with sanding after each coat)
Paint the frame (3-4 light coats, with sanding after each coat)
Apply 2K clear coat (2-3 light coats, with sanding after each coat)
Final touches, cutting, and polishing
List of supplies (with links)
Cannondale Track Decal Set (sourced from Ebay)
Painter's tape (for covering BB opening, headset cups, and fork dropouts)
I don't have many photos documenting the process itself, and there's a reason for that. Lighting. Almost all of this happened late at night in our front yard after my kids were in bed for the night. And to be honest, the process also wasn't that visually appealing to document -- all of the painting and prep work was done outdoors by literally hanging the frame by the rear brake mount using a bent wire clothes hanger that I had dangling from the basketball net in our driveway. If you use your imagination you might be able to picture how absurd this setup looked.
From here on out, note that for ALL of the steps in frame restoration -- stripping, sanding, priming, and painting -- I wore gloves and used a fitted respirator, and STRONGLY advise anyone who takes on a similar project to do the same. The chemicals in these products are not worth inhaling, and N95 and surgical masks simply aren't going to cut it. If you decide to take on a similar project, wear a respirator and gloves. They're inexpensive and entirely worth it.
Stripping the frame with aircraft paint remover was pretty straight forward. I opted for an aerosolized version picked up from my local autoparts store. A single can was enough for me to strip one frame.
I applied a liberal coating of the stripper to the entire frame and let it sit for approximately 45 min. This got rid of most of the paint, however there were quite a few stubborn areas that required a second coating. Did I mention that I wore a respirator and gloves throughout the entire process? If you take on a similar project, you should too. Be prepared for this step to be a fairly large mess, and dispose of any leftover paint and chemical waste appropriately.
If there happens to be any remaining paint on the frame after the stripping step, it's probably easiest to just sand that off. In my case, paint stripping got rid of ~99% of the paint, with only a few areas near cable housing stops and between chainstays that needed some extra help with sandpaper.
For the pre-primer sanding step, I opted for a 600 grit sandpaper and did a wet sand of the entire frame using medium pressure. The goals here are to simply smooth out any rough areas, remove any residual paint, and provide a surface for primer to adhere. No need to go crazy.
Stripped, sanded, and ready for primer:
With the frame stripped and sanded, it was ready for primer. For this step I chose to use Montana's Universal Spray Primer and felt it gave good results, but again I don't have much prior experience to compare with. The application of primer (and paint, for that matter) was pretty straightforward. Follow the instructions on the can, shake well, and apply light coats in a consistent spraying motion by holding the can ~10 inches away from the surface of the frame.
The first coat went on easy, and at this step the frame appeared to be almost entirely coated with primer with a few glimpses of raw alloy peeking through in spots. I let the first coat of primer sit for 24 hours before moving on to the next coat. After that 24 hour drying time but before I applied the second primer coat, I did a light sanding with 1200 grit sandpaper to get rid of any imperfections. My approach with this sanding step was to be brief but thorough in getting rid of any obvious errors -- just enough to smooth things down but not enough to eat through the first coat.
The second coat of primer went on equally as easy. I let that sit for another 24 hours, then again sanded out any blemishes with 1200 grit sandpaper.
Applying paint to the frame
To be honest, this step wasn't much too different than the primer step, aside from the fact that I applied an additional coat of paint (3 total). I've always been a fan of the early 90's Cannondale track frames in their metallic blue paint, and as an homage to those framesets I selected a paint that got me as close as possible to this color. I tested a few different options, but ultimately settled on the Montana Metallic Ice Blue.
The steps with spray painting were simple. I gave the primed frame a quick rubdown with a microfiber cloth dampened with 70% ethanol to remove any contaminants prior to painting, and then jumped right into it. Again, the strategy here was add a light coat of paint, let sit 24 hours, give the frame a light sanding with 1200 grit sandpaper, then rinse and repeat two more times. Not much else to really add here, other than it's better to spray several light layers of paint rather than fewer, thicker layers. Going into a project like this, if you want good results you've got to be patient. It's going to take at least a week even if everything goes perfectly throughout the whole process.
After the final coat of paint, the frame was looking pretty awesome, albeit a bit flat. At this stage, I let the frame hang in my garage for 3 full days to give the paint a bit more time to dry out and cure. Not sure how necessary this step is towards achieving a good result, but I was paranoid that if the paint was still somewhat "fresh" then I might risk not only poor adhesion with the decals but also the possibility of a reaction between the paint and the 2K primer.
I sourced a set of Cannondale track decals from a UK seller on Ebay and was pleased with the quality. Application of the decals was also pretty easy. Check reference images online for downtube decal placement, measure twice and take your time.
Applying 2K primer
It wasn't until application of the primer that the frame color really started to "pop" and I got my first glimpse at how this project was going to turn out. For this step you NEED to go with a 2K primer. I opted to use SprayMax 2K Glamour High Gloss Clear Coat and was really impressed not only by the quality of the clear coat itself but also the quality of the nozzle and spray pattern. If you're thinking about taking on a similar project, don't even think twice about this step -- just go with the 2K option I linked above. I have worked with regular 1K clear coats previously, and the 2K spray is hands down a better choice and will lead to a much higher quality, more durable finish.
Again, the steps to applying the 2K clear coat are similar to the previous steps I outlined in the painting section above. 2-3 light coats, with a minimum 24 hour drying time before light sanding (1200 grit) and subsequent coats of clear.
After the final coat of 2K clear, I let the frame hang undisturbed over the weekend before proceeding with a few final touches to get the frame as polished and professional as possible.
Final touchups and polishing
After the clear coat had dried and hardened, it was looking pretty good and the high gloss finish of the 2K clear coat really helped bring out the shine in the metallic blue paint. To achieve an even higher level of quality, I decided to take a few extra steps that I think added to the result I ultimately achieved with this project.
After a final clear coat sanding step with 1200 grit paper, I continued on with a 2000 grit sanding step over the entire frame to further smooth out any imperfections. I then proceeded with a cutting step using a microfiber cloth and Meguiar's Ultimate cutting compound to buff out any remaining imperfections, and then tacked on a final polishing step using Meguiar's Hybrid Ceramic spray wax, applied as directed.
The final results speak for themselves, I hope. I was totally satisfied with the way things ended up, despite the level of effort and time that went into this.
And that's it! For the frame, at least. :)
Finding a suitable fork
At this point you've probably long forgotten about the fork dilemma at the start of this entry. A custom-painted DIY frame doesn't have much utility without a fork, so for that I ended up sourcing a used Columbus Minimal with a 1" threadless carbon steerer tube. Fortuitously, this fork happens to have the same rake/trail parameters as the stock Cannondale fork it replaced, so handling on the frame should still be darn near close to the way Cannondale designed it.
The prep and painting of this fork was more or less identical to the steps I undertook with the frame itself, however given that the fork is full carbon fiber, I did not fully sand away the original paint and primer, but rather simply roughed up the existing paint with 600 grit sandpaper to provide good adhesion for subsequent prime and paint steps. It probably goes without saying, but I also taped off the carbon steerer tube itself.
Building up the bike
I'm not going to go into too much detail about the parts selection for this bike, but figured I would provide a spec list below in case anyone was interested.
The only major customized part here was the hand-brushed alloy Easton EA90 crank arms. These cranks are only sold with a stock anodized black finish, and that simply wasn't going to cut it with the vision I had for this build. For this step, I applied oven cleaner to any anodized surface for 5-10 minutes or only as long as it took for the anodization to "melt" off. If you decide to do something similar, be sure to do this step in a well-ventilated area with a mask and gloves! Following removal of the anodization, I then used a green Scotchbrite pad to give the crank arms their final brushed finish. They turned out awesome, as you can see in the photo gallery below:
Without further ado, here is the complete parts list:
SRAM Red eTap 22 rim brake shifters
SRAM Red eTap rear derailleur (with clutch, for use with 1x drivetrains)
SRAM Red 22 rim brake calipers
Garbaruk Components radial chainring (52T) compatible with Cinch crank arms
Speedplay X2 stainless pedals
FSE 35mm Tubular rims
Sapim CX-Ray spokes
Cockpit, saddle, and miscellaneous
Ritchey 1" to 1 1/8" stem shim (allows for using modern 1 1/8" stems with older 1" threadless forks)
Chris King 1" threadless headset (polished silver)
Kalloy Uno seatpost (polished, silver)
Generic carbon saddle (sourced from Ebay)
Generic alloy seatpost clamp (sourced from Aliexpress, then custom sanded for brushed raw alloy finish)
King Cage stainless water bottle cages
Complete weight of entire build: 14.8 lbs (6.71 kg)
Not bad for a late 90's aluminum frameset!
And below is the gallery with the final build. All photos taken by me with a Sony A7RII.
LAST BUT NOT LEAST!
I'm a one man operation and everything you see on this site is simply a passion project for me. I fund this website by selling prints and apparel featuring my original bicycle-centric sketches and illustrations, which you can find in my online shop. If you found this post at all helpful or if you enjoy the projects I take on, please consider supporting this site by purchasing a print or t-shirt. And if you'd like to stay up to date on future projects and art releases, please consider subscribing at the link below.