Rising From the Ashes

Like Dumbledore’s Phoenix, Fawkes, witness this Cervelo S5 rise from the ashes.

By: Andy Schmit

It’s been the season of restorations in “the shop” of late. I’m not sure if this can be officially called a trend, but with the COVID-19 supply-chain shortages of new bikes, frames and components, it may be. So, instead of celebrating “new bike day,” maybe we will be celebrating more “returned to its former glory days” this year.

This is Part 1 of a two-part series, it really takes more of a technical look at the considerations of bringing a well-loved bike back to race ready. Part 2 will also look at the process, but through the lens of the bike’s owner / rider.

I just finished taking a 2012 Cervelo S5 from non-functional, back to race ready. Like a Phoenix rising from the ashes, the only parts to remain on the bike throughout the process were the bottle cages. Everything had to be taken off the frame, and either cleaned and refit, or replaced.

I’d seen this particular bike before, when its new owner brought it in shortly after purchasing it for the often-concerning, “it’s making a funny sound,” situation.

Relatively speaking, that was an easy fix. The previous owner had fitted a set of 700 X 28c tires on the bike. Now mind you, the trend toward wider rim widths and larger tires has been around for a few years. But this is a 2012 Cervelo S5, with Shimano Ultegra 6870 Di2, which means it was never designed to be ridden with that large a tire. The “funny sound” was the tire rubbing on the underside of the seat tube cut away.

For those of you not familiar with the Cervelo S5, it is an aero road bike that has a distinctive seat tube / rear triangle design that is more akin to a TT/Tri frame than a traditional carbon road frame.

303 Cycling | Cervelo S5

Luckily, we caught it before serious frame damage occurred, but I did put a strip of helicopter tape on the underside of the seat tube cut out to protect the remaining paint, after fitting some Continental GP 4000II s 700 X 25C tires. The moral of this story… if you’re riding an older frame, make sure you check the specs of the bike, before getting new trendy “big – wide” shoes for it.

We now return to our regularly scheduled programming of restoring this bike to its former glory. When it came back to “the shop” this time, it was because it wasn’t shifting, at all.

You could press the shifter and nothing, nada, zip… the derailleurs did not move.

Initially the owner thought the battery may have failed, so she purchased a new one. Sadly, that did not solve the problem.

So, now it’s time to get out the Shimano PC Linkage and Diagnostic Device. If you’d have told me I’d need a computer to work on a bike when I was first learning to wrench, I’d have said you were daft. Yet, here we are.

Step 1, use the diagnostic tool to connect to and troubleshoot each component. I won’t bore you with the intricacies of using the “black box” and the Shimano E-Tube project software, so we can cut to the chase.

All the components checked out, though some did require a firmware update. Which, by the way, is a good habit to get into with any Shimano Di2 or SRAM eTap system.

Manufacturers are constantly issuing bug fixes and updates to improve the performance and reliability of their electronic shifting options. So, keeping your firmware up-to-date can often eliminate untimely and inconvenient roadside issues.

While I was running diagnostic on the shifters, I saw some black electrical tape on the wiring harness near the integrated junction box.

303 Cycling | Shimano Di2 Junction Boxes

Since this is a Shimano 6870 Di2 equipped bike, the Junction Box A isn’t really a traditional junction box as in modern Di2 systems. It’s essentially a wiring harness with eTube wires to go to each shifter and a plastic “female” connector on the integrated junction box to go to the eTube wire in the downtube.

Shimano abandoned this in the next generation of Di2 when they introduced the separate 3-port and 5-port Junction Box A’s with no integrated eTubes. I think partially because of build flexibility and this particular system was a throwback to the original Di2 system of Dura-Ace 7970 which was not eTube. By separating the junction box from the wires, it allows the builder to select the proper length eTube wire for the handlebar width and do a “cleaner” install on bikes equipped with aero bars. Oh, and did I mention almost all of the previous integrated junction boxes cracked sooner or later.

Sure enough, the electrical tape was covering up a broken female port on the wiring harness. Instead of replacing the harness when it broke, the previous owner elected to bodge it together with enough electrical tape to subdue a would-be assailant. Which clearly was a less-than-effective repair as the eTube slipped out of the connector with the slightest tension.

It’s probably a good time to mention that the previous owner stated at the time of purchase, “my boyfriend maintained my bike.”  And… If I hear these words again, I’m throwing down my tools in disgust running away from home.

A modern bike is a complex collection of components, wheels and likely a composite frame. They all have specific tolerances, torque values and maintenance intervals and requirements. Bottom line, they need a professional to work on them. Full stop.

So, the previous owner’s “fix” necessitated totally re-doing the front cockpit of the bike. New eTube wires, a 3-port Junction Box A and an aftermarket junction box mount. You could use the Shimano-supplied “rubber band” to wrap around the stem, but I’m not a fan. It looks like a kludge, and I’ve seen far too many of them get brittle in the sun and snap at the most inopportune moments.

303 Cycling | Shimano Mounting Options

3030 Cycling | Bar End Di2 Junction Box

Photo: Courtesy of Shimano America.

Now, you more Di2 savvy readers might be thinking, “why not use the new bar-end junction box released with Dura-Ace 9150 Di2?” Well, it’s not just the junction box, you also need a pair of handle bars specifically designed for internal Di2 wiring, which these are not, given they were manufactured prior to the internal junction box being invented. But good on ya for thinking of it.




After rewiring the handlebars, I replaced the brake housing and cables. This is one of those “while you’re there, put in a clutch” type situations when you’re refurbishing a bike. It just makes good sense, especially if you are going to replace the handlebar tape. Over time, brake and shift cables will get kinked or the cable housing will get fouled with grit and other contaminants. Thus, reducing their performance and reliability. Replacing it is not a big expense, but it pays dividends in the long run.

And then came the drive train, which was pretty straight forward. Installed new 50/34 ROTOR NoQ chain rings on the ROTOR 3D30+ crankset, replaced the cassette and the chain. But this uncovered the last two surprises.

“Surprise” in this case is a lot like Dumbledore getting an ear wax flavored treat in his box of Bertie Bott’s Every Flavor Beans.

303 Cycling | Park Tool PF30 Bottom Bracket ToolThe first was discovering that the bottom bracket bearings had never been changed since they were originally installed when the bike was built in 2011. They barely turned, were completely corroded and “crunchy.” That is to say, when you rotated the bearings, you could literally hear the grit and corrosion making noise. So, using a Park Tool press-fit bottom bracket removal tool, out they came.

Yep, the dead blow hammer had to come out. That’s the big red mallet in the lower part of the photo. It’s always bothered me since the dawn of the press-fit bottom bracket age that a hammer would be involved in removal. But in the era this bike was manufactured, frame manufacturers had a very difficult time gauging how much or how little carbon composites would shrink during the curing process.

The frame and the bottom bracket cups have to be manufactured to tolerances within a couple hundredths of an inch, which is about the width of a human hair. So, sleeve retaining compound (aka high-tech glue) was necessary to fill the gaps between the bottom bracket cups and the frame. This is what lead to the almost inevitable bottom bracket creak so commonly heard on group rides in that era.

After banging out the worn out bottom bracket and cups, I installed a Wheels Manufacturing Thread Together Bottom Bracket. The thing that makes these bottom brackets great, aside from being manufactured right here in Colorado, they use two CNC machined aluminum cups that thread together keeping the bottom bracket stable and parallel in the frame.

They are available with steel, angular contact and ceramic bearings and I use them in almost every new build I do. They’re not sexy, but they work, and are my first line of defense in preventing the dreaded bottom bracket creak that is so common with PF30, BBRight® and other interference fit standards. The second line of defense is using Morgan Blue Aqua Proof Paste, it is by far the best non-petroleum-based waterproof grease I have encountered.

The second “surprise” during this particular re-build was that the rear hub likely had never been serviced, ever. The bike has a set of Mavic Ksyrium Elite wheels, which is a pretty good set of light-weight alloy wheels. But like all Mavic wheels that use the FTS-L hub design they need to be serviced regularly.

How regularly you ask? In Colorado, I’d say every six months. Or more frequently, depending upon your proclivity for riding in inclement weather.

Why, because Mavic until recently used mineral oil to lubricate their freehub bodies, rather than some form of grease? Take a look at the before and after pictures, see if you think some service was needed.

303 Cycling | Mavic Hub Service

Before cleaning and applying new Mavic mineral oil, I’m surprised the pawls (the small spring-loaded flipper seen in the picture to the left) were even engaging the ratchet in the freehub body. That’s the part of the hub the cassette is mounted to, and allows the wheel to spin while you are not pedaling. The clicking sound you hear when you are coasting are the pawls engaging the ratchet of the freehub body.

A few more bits and bobs, including new Cinelli Cork Handle Bar tape, and it was time for “returned to it’s former glory day.”

Like Fawkes, Dumbledore’s loyal Phoenix after “burning day.”. This Cervelo S5 was back to race ready.

While “new bike day” is always fun, there is something special about taking a high-mileage bike back from the brink and returning it to race ready. It’s also the “greener” way to go, as only 20% of carbon fiber is currently being recycled, and 80% is ending up in the landfill.

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1 Comment

  1. Ilene Carpenter

    Whoever owns that bike is going to love having it reborn. Thank you for making details I don’t care about so amusing, i’m glad you care about them!


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