Technical FAQ: Hill gradients, Campagnolo derailleur capacity, IT bands

This article originally appeared on Velo News

Have a question for Lennard? Please email us veloqna@comcast.net to be included in Technical FAQ.

Dear Lennard,

I have noticed that different climbs with the same gradient do not have the same perceived difficulty. Do you think that the curvature (i.e., second derivative) of the climb might have an impact on the perceived difficulty of the climb?

In fact, my query relates more to short climbs (< 1km long). Say when the gradient hits 7 percent it appears easier on some other hills where the gradient is 7 per cent. Of course, this could just be the delay in registering the gradient from the Garmin, at which time it's not physically 7 percent but something less. Nevertheless, I still ponder over my original query as to whether the hill curvature makes a particular hill harder or easier for a given gradient.

- Jim

Dear Jim,

I've never intentionally compared different climbs this way, and I'm not sure I've noticed a perceived difficulty difference between climbs of identical gradient other than due to a difference in temperature, road surface, or personal condition or level of fatigue. I asked Trevor Connor, owner of Fast Talk Laboratories, famed cycling coach and an exercise physiology guru in the bike technology business, what he thought. He said this:

“That's an interesting question from Jim. I have thought about gradients, but I have seen little to no research on the subject. All the research I've found compares hills to flats. They rarely address variance in grade. Would be a really interesting subject to explore. I do know from the existing research that riding on a grade changes the neuromuscular pattern of the pedal stroke. I wonder if the change in the pedal stroke does also change or increase with the change in grade. If so, that would effectively allow you to "feel" the grade.

The other thing I've seen in the research is that most of the differences between riding on a grade and on flats are simply due to the lower cadence on a climb. So, addressing Jim's questions, assuming he's already in his lowest gear, as grade increases, his cadence is going to drop, and he may be perceiving that as increased difficulty. Don't need to tell you this, but even a really steep climb can feel easier if you have a cassette with a giant easy ring.”

Trevor Connor
Fast Talk Laboratories

And this is what Jean-Paul Ballard of Swiss Side says in response to your question:

“We do a lot of analysis of this kind of thing. In the end I think that there are two things to consider. One is the average gradient, and the other is the local maximum gradients. It's clear that a climb with a constant 8% is going to feel more consistent and possibly easier than one which ramps up and down in gradient. With increasing gradient, riders tend to naturally push high watts. So ramping gradients will push the rider into higher power zones more often which can lead to more lactic acid build up and feeling worse. On a constant climb, a rider finds their highest sustainable power output and stays there.”

Jean-Paul Ballard
Swiss Side CEO and co-founder

You may be accurately sensing an increase in physiological demand based on differences in curvature of two climbs of identical average gradient, Jim.

-- Lennard

Dear Lennard,

You seem to get frequent Campagnolo questions and I’ve seen a lot of discussion on short cage length and compatibility with larger cogsets. I have a post-2011 Athena derailleur that works fine with a 28 (12-28), but I’ve seen mixed comments about being able to getting a 32 to work.

The hanger is a D902.

I don’t see a replacement medium cage available for the Athena, I assume some of the medium cage replacements for Chorus, etc. will not fit?

This is primarily a CX bike that is now being used for gravel and in most cases the 28 has been sufficient, but some of the rides we have recently done have put me at a disadvantage to others with 1x and taller gearing. (Repeated climbing at 40ish RPM is not that pleasant and I don’t want to upgrade the whole bike to Ekar).

If I needed to upgrade the mech, I could go with a new Potenza 11, but they seem to be hard to find, even online.

- Pete

Dear Pete,

Here's the answer from Buddy Spafford, Campagnolo North America's tech service director:

“There's a lot to unpack here, so let's begin. Firstly, the maximum sprocket the Athena 11 derailleur can fit is a 29t. With the exception of some late entries in 11-speed just before the 12-speed switch, the 29t max applies to all generations and versions of 11-speed. We never made a 12-28 11-speed cassette, since our large sprocket numberings end in odd teeth count (25, 27, 29.) The customer's derailleur would work with our 12-29 11-speed cassette, which is at the maximum for this derailleur

I think there is sometimes confusion about long-cage variant derailleurs with Campagnolo. A medium or long cage helps to add extra capacity. This means the system can absorb more links of chain from greater differences between the smallest and largest chainrings or sprockets. For example, we made an Athena 11 Triple rear derailleur which had a long cage to handle the larger capacity change between a 52t large and 30t small ring on a triple crankset. The cage allows the take up of more chain but does not add anything to maximum sprocket capabilities of the rear derailleur. This would have to be done by changing the derailleur parallelogram, body, and upper pulley position. So, long story long, a long cage does not mean it can fit a larger sprocket necessarily.

This changes when Potenza is launched in the medium-cage variant that accepts a 32t sprocket. The Potenza derailleur has a different asymmetric parallelogram, paired with the longer cage, that allows a larger maximum sprocket and the ability to correctly handle the capacity change of an 11-32 cassette in the rear. This also applies to the 2018 versions of Chorus, Record and Super Record 11 medium-cage derailleurs, which were launched just before 12-speed.

Because the Potenza uses a different parallelogram, it also requires a different pulling ratio from the shifter, which means your reader cannot simply swap to a Potenza rear derailleur and expect it to work correctly with their original Athena shifters. Their shifters pull cable for the older parallelogram and will not work correctly with Potenza. Or any of the 2015 or later derailleurs which use this asymmetric parallelogram.”

Buddy Spafford
North America Technical Service (East)
Campagnolo North America, Inc.

Given those limitations, Pete, you might want to consider first trying your existing derailleur with a Wolf Tooth RoadLink ; it should work with your D902 derailleur hanger. To otherwise get your system to handle the 32T cog, you are talking about a new derailleur and shifter, so, before spending that kind of money, it's worth spending 22 bucks on one of these and giving it a try, IMHO.

-- Lennard

Dear Lennard,

I just read your latest about the IT band and wanted to respond with something I learned as a fitter. Shoe insoles, while they have improved, still tend to be less supportive than needed for the downward force applied to feet when riding. Arch compression just unleashes a variety of problems since the foot rolls when not properly supported as you described. Sole makes insoles that are designed for cycling; they are thin, and they are heat moldable. They improved life for a countless number of my fit customers; they are pretty inexpensive (especially in cycling terms, haha), and I have some that are still going strong after several years and a few moldings.

- Scott

Lennard Zinn, our longtime technical writer, joined VeloNews in 1987. He is also a custom frame builder (www.zinncycles.com) and purveyor of non-custom huge bikes (bikeclydesdale.com), a former U.S. national team rider, co-author of “The Haywire Heart,” and author of many bicycle books including “Zinn and the Art of Road Bike Maintenance,” “DVD, as well as “Zinn and the Art of Triathlon Bikes” and “Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists.”
He holds a bachelor's in physics from Colorado College.

Follow @lennardzinn on Twitter.

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