Bikes and Tech
Campy EPS V2 requires a hole drilled in the frame...

Technical FAQ: Tons of Campagnolo questions

Lennard Zinn answers questions about Campy EPS compatibility, whether you can save money on non-Campy parts, and more.

Dear Lennard,
I have first-generation Campagnolo Record EPS on my bike. It has an external battery bolted under the water bottle on the down tube. Can I switch to the internal battery and still use my existing shifters and derailleurs?
— George

Dear George,
Yes, you can. You have Version 1, and Campagnolo has had the Version 2 (V2) internal-battery system out for a few years. I made this upgrade myself on my Campy EPS bike a couple of years ago, switching from the V1 external battery to the V2 internal battery. Now, however, V3 is available, or will be very soon, and you can upgrade to that one, which would be my recommendation.

To upgrade to V2, you have to drill a hole for the V2 charger port somewhere down near the bottom bracket. I drilled mine under the down tube (see photo). Drilling a hole in your frame will certainly void the warranty.

That’s not the only extra hassle, however, since, unlike a Shimano Di2 internal battery, the V2 battery does not fit in the seatpost. Rather, it mounts deep down in the seat tube (or, in some large-diameter monocoque carbon frames it can go inside the down tube) and affixes to the inside of the tube by means of double-threaded screws that hold the water bottle cage on. You need a special tool to reach the battery in there and hold it in place. It can be a bit of pain to get the charger port to make the bend from inside of the bottom bracket shell to pop out of the hole in the down tube.

If you upgrade to V3, however, you don’t need to drill a hole in the frame (because V3 charges at the EPS interface up at the stem, like Di2), and you can install the battery inside of a seatpost. This makes it much easier and won’t void any frame warranty. Full instructions for installing all EPS versions are in “Zinn and the Art of Road Bike Maintenance, 5th Edition.

Furthermore, you can do a lot more with V3. You can get the My Campy app on iTunes or on the Android Play Store, and it allows you to very simply and easily change the functionality of your EPS shifters. For instance, you can impart shifting logic like SRAM eTap to them, or you can make all shift commands come from only one lever (great for various disabilities). Additionally, you can sync your EPS with a Garmin to display a lot of the features the app does, like what gear you are in both numerically and graphically.

What’s nice is that all of these upgrades do not make your existing derailleurs obsolete; everything works fine together no matter what the generation of battery and interface you have.
― Lennard

Dear Lennard,
I recently chose to replace the somewhat worn chainrings on my 2008 Chorus Carbon CT crank.

Wanting to see how they would perform, I chose a set of FSA rings in the same 34/50 gearing.

When the rings arrived I raced to install them and was very much surprised by what I found.

Not all five of the Campagnolo chainring bolts are on the 110mm circle. One of the bolts, the one hidden behind the crank, is on a roughly 112mm circle.

I verified this by rotating the OEM rings one hole position.

I cannot find any mention of this in any Campagnolo paperwork or for that matter any place selling Campagnolo ‘compatible’ chainrings.

Can you verify this or do I have an (unlikely) one-off crankset? Does anyone manufacturing Campagnolo 110mm bolt ‘sort-of’ circle compatible rings?
— Antonio

Dear Antonio,
Welcome to the world of Campagnolo. Campgnolo compact chainrings only fit on Campagnolo compact cranks, and vice versa. “Compact” means a chainring bolt circle diameter of 110mm (i.e., 110BCD), but Campagnolo only adheres to that with four of the five holes. As you discovered, the fifth (hidden) hole is drilled further out — at 112mm BCD.

In a way, Campagnolo is doing you a favor by making sure those FSA chainrings don’t fit on your crank, because your crank has a hidden spider arm, and hence a hidden bolt, behind the crank arm. A standard compact chainring designed for a standard 5-arm compact crank will have one spider arm opposite the crankarm. So a standard compact chainring will be “clocked” off by 36 degrees if it is bolted onto a crank with a hidden spider arm (and hence no spider arm opposite the crankarm). Read the question about SRAM 22 chainrings in last week’s column for more explanation on this issue.

Campagnolo has long been loath to make their chainrings compatible with anybody else’s. When I started racing, Campagnolo road cranks had a 144mm BCD, which was the same as track cranks. These long spider arms meant that 42T was the smallest chainring you could mount on a Campy double road crank. When Shimano introduced 130mm BCD cranks, riders flocked to them because they could mount a 39T inner chainring on them. Campagnolo eventually followed, but it didn’t go to 130BCD. Instead, Campagnolo road cranks became 135mm BCD. The spider arms were still short enough that a 39T chainring could be mounted, but, of course, it could only be a Campagnolo chainring, since essentially all available chainrings from other brands were 130BCD.

Campagnolo will tell you that its parts are designed to be used as a system, and it does not want mixing and matching of other components that could compromise its shifting performance, durability, or strength. Shimano and SRAM do similar things, just not with chainrings (except maybe now with SRAM 22 chainrings).

I’m afraid you’re going to have to bite the bullet and buy some Campagnolo replacement chainrings. They’re not cheap, I know, but no other manufacturer that I know of offers Campy-compatible compact road chainrings.
― Lennard

Dear Lennard,
My bike is a titanium, external-cable model that fits me perfectly, and I have no desire to change. My wheels are all Campagnolo and I’m running a Record 11-speed groupset. I’d like to go electronic, but Campy EPS requires internal cable runs, and I don’t want to get into drilling holes/etc.

Could I simply use SRAM eTAP shifters and front/rear derailleurs, keeping the wheels/crank/cassette? I’d put on a new chain, and I suspect I’d be best to stay with a Campy chain, but would a SRAM chain work better?
— Marc

Dear Marc,
Yes, you could do that. The cassette would shift fine, whether you use a SRAM or Campy 11-speed chain. I don’t know which one would work better on your system of Campy chainrings and cogs with SRAM derailleurs. Note that SRAM’s eTap rear derailleur isn’t intended for cassettes with cogs larger than 28T.
― Lennard

Dear Lennard,
A Ridley bike I’m considering buying (see photo) has Campy Record 11-speed EPS. The crankset is 50/34 compact. Am I correct that this short-cage rear derailleur will accommodate a 12-29 cassette? (I have been running Campy Record 10-speed, and with a 50/34 crankset I needed a mid-cage rear derailleur to use a 13-29 cassette.) I know from your columns that I can also interchange with Shimano cassettes — can I use an 11-28 Shimano cassette as well?
— Andy

Dear Andy,
Yes, the Campy short-cage 11-speed EPS rear derailleur will handle a 12-29 (or 11-29) cassette. I have that same derailleur and run an 11-29 with it.

And yes, you can use an 11-28 Shimano cassette with that drivetrain, but you can’t put it on that Campy Bullet wheel as-is; you need a Shimano-compatible freehub.
― Lennard

Dear Lennard,
I have read all of the responses to the 11-speed compatibility report you compiled. Thanks for the great information.

My question is with regards to Campagnolo EPS. I built up my gravel grinder/road rig with Campagnolo EPS V2 and I have an Easton EC90 XC 29er wheel set, which can only accept a Shimano or SRAM 11-speed freehub.

I do not want to purchase another wheel, as I really like the Easton set up. Do you anticipate any issues with the SRAM Red 22 cassette with KMC 11-speed chain and a Campagnolo SR EPS gear set? Also I am running a Cannondale Hollowgram 50/34 crankset.
— Robert

Dear Robert,
No, I don’t anticipate any issues running Campy EPS with a SRAM 11-speed cassette and KMC 11-speed chain.
― Lennard

Dear Lennard,
It is becoming more difficult to find mid-priced wheels that are Campy compatible. How difficult or feasible is it to buy a Shimano or SRAM wheel set and replace the freehub with a Campy freehub?
— Dennis

Dear Dennis,
It’s not a big deal with a lot of brands. Mavic is certainly one example, but lots of manufacturers offer both Shimano-compatible and Campagnolo-compatible freehub bodies for their wheels, even at lower price points. The switch is quite simple and straightforward with many brands as well and often takes only a couple of hex keys or simply pulling the axle end cap.
― Lennard