Converting Your Bike to a Hybrid Disc/Rim Brake Setup, Part 1

Today I’d like to introduce my friend and fellow bicycle nut, Bruce Ross. He has a Colnago he loves so much he wanted to upgrade it with disc braking – even if only on the front. He wrote up the whole project, from his decision to upgrade to everything involved in adding the brake, and ride impressions. I love a good upgrade and am sharing Bruce’s story with you in the next two Tech Talks. I’ll let Bruce take it from here. —Jim Langley

By Bruce L. Ross

“Disc brakes are increasingly making their way into the road bike market, and it is now very possible to convert your “keeper” standard rim brake road frame into a hybrid mix of disc brake front and rim brake rear. (That’s my keeper below, in its “before” spec: a 2011 Colnago C59 Italia.) In the not-too-distant future it is likely that full disc brake road bikes will be the norm, particularly for most high-end road machines. Wanting to get one of my rim brake frames acquainted with the 21st century standard was one of my main motivations for doing this conversion.

While this is an exciting time for the bike industry it is also confusing for most consumers, as many changes are happening that affect how bikes are constructed and what components are available to match these changes. Disc brakes that have been so common on mountain bikes for the past several years are now transitioning over to road bikes. The challenge now for road disc brakes is to make them both smaller and lighter, while still maintaining their excellent stopping power.

I know this article won’t necessarily inspire you to perform this transition on one of your own road bikes, but providing a description of the process I went through to get the job done will at least show what it takes should you ever decide to take the plunge.

Why Do This?

The answer for me and many other roadies is that a) disc brakes are better brakes, possessing greater stopping power with less force applied, b) rim brakes on carbon fiber wheels just don’t have the same modulation (rider-adjusted input) as discs and c) rim brakes on carbon fiber wheels are less reliable than discs, especially in wet conditions.

Having said this, carbon fiber wheel manufacturers have made great strides in recent years to both improve the braking surface of their carbon wheels as well as improving the composition of brake pads, both of which increase the reliability and security of rim brakes while reducing the degradation of the braking surface as well.

Still, the path forward in the bicycle industry is clearly in favor of disc brakes on all types of bicycles. It just seems to be the case that road bikes are lagging behind a bit, probably due to the fact that pros are eschewing disc brake technology currently.

What to Consider

Should you want to make this change to one of your bikes, there are several decisions you need to keep in mind, including:

1) What fork will be compatible with your frame, both functionally and aesthetically?

2) What wheel(s) do you want that offer disc brake application?

3) What type of disc brake do you want to use – hydraulic or cable-actuated?

4) What rotor will you use?

5) What disc pads will you use?

The Process

I had been thinking about doing this for quite some time and chose one of my “keeper” bikes, a 2011 Colnago C59 Italia, which is a special bike in my stable. Colnago has had several years’ worth of experience with building disc forks, so I was comfortable with using one of their disc forks to replace my old rim brake fork (I’ve provided a forks photo so you can see the difference).

I discussed this project with the “brain trust” at my local shop, The Spokesman Bicycles in Santa Cruz, California. They are an expert, high-end shop in my city with one of the best road bike mechanics (Harry Gurnee) I’ve ever met. Upon first hearing of my plans, some employees at the shop pushed back on the idea for this project, claiming “it’s not traditional” and “you won’t be able to sell the bike if you eventually want to” and “it will look weird.”

However, once I got everyone on board with the project, all of these comments vanished as they all became intrigued with the process and wanted to pitch in, even offering helpful advice.

Please tune in next week for Part 2. Bruce tells us all the parts he chose and why, breaks down the total cost and rates the results. Bruce welcomes questions and comments (see below).

Bruce L. Ross is a psychotherapist, international specialty woods broker and long-time cyclist (44+ years and counting) who lives, works and rides in Santa Cruz, California. Bruce owns several bicycles and splits his riding time between road and mountain. For questions or comments, he can be reached at blross@got.net.

Jim Langley

Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s streak of consecutive cycling days has reached more than 8,000. Click to read Jim’s full bio.