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Chain hop

Dear Lennard,
I have a Campy Record 11-speed EPS group on my Colnago C64. Aside from one issue, everything has been great with this combo of frame and components.

My problem is chain hop in the 34×13, 34×14, and 34×15 gear combinations. This occurs while under pressure and does NOT occur while in the big chainring (50-tooth) no matter what, if any, pressure on the big ring.

I do have your road bike maintenance book (4th edition) and consulted it. Nothing, including removing a chain link (I do have a 11×29 cassette) to go from 108 links to 106 has solved the problem.

Also, I have used three different models of 11-speed chains and the problem remains.
— Mark

Dear Mark,
I believe you have either worn out those cogs due to using them the most or your chain is being grabbed by the pickup teeth on the inboard side of your big chainring. If it’s the former, it only happens on the inner chainring under high load because there is a high amount of force wanting to yank the chain out of the worn teeth coupled with less derailleur tension holding the chain on a bit tighter. If it’s the latter, it doesn’t happen in lower gears because the chain line to the larger cogs doesn’t bring it so close to the 50T ring.

Check for cog wear with visual inspection (look for a hook shape to the teeth) or with a sprocket checker tool like the Rohloff HG-IG-Check tool. Unior and KMC make similar tools. You can also try putting a more worn chain on and see if the skipping goes away. If the cogs are worn, replace them.

If it is the chain hitting the large chainring, this is more likely to occur on bikes with a 34-50 front chainring combination because the 16-tooth size differential is so much more extreme than the 14-tooth jump from a 39T ring to a 53T. It happens more under heavy load, because the chain is so taut that it is less likely to just slide off the pickup teeth when it hits them. To avoid this exact occurrence, current Shimano Di2, for example, will no longer allow you to shift to the smallest two cogs when in the inner chainring. The solution for you is to not use those cross gears.
― Lennard

Downtube shifting

Dear Lennard,
I am building up a 650B Rando bike and want to use Campy 10-speed downtube shifters. I know Campy didn’t make 10-speed downtube shifters, but they made a limited amount of 9-speed downtube shifters. I have a set of 9s and was wondering if I bought the internals of 10-speed bar-end shifters, could I convert them to indexed 10?
— James

Dear James,
I have not tried that, but I think it is likely to work. I have mounted Campy frictional bar-end shifters on downtube shifter bosses and would not be surprised if indexed ones work that way as well.

The backing nut on Campy bar-end shifters is shaped like a downtube shifter boss, so those internals are likely to work on your frame’s shifter bosses. I don’t have one of those shifters around here anymore to look at, but if you were to look at illustration 5.44B on page 105 of the 5th Edition of “Zinn and the Art of Road Bike Maintenance” (this illustration appears in earlier editions as well, with a different number and on a different page), you can see that the backing nut resembles a downtube shifter boss.

You may find that it works better with the lever of the bar-end shifter rather than the 9-speed lever you have.
― Lennard

Cleat position

Dear Lennard,
Over the years, I’ve gotten the impression that moving the cleat toward the center of the shoe will obtain the best possible power transfer, but only Speedplay offers a special adaptor to allow more movement. Why do you think we don’t see more fore and aft cleat adjustability from manufacturers?
— Jeff

Dear Jeff,
It’s because not enough people demand it. I personally think that anyone with big feet ought to have their cleats further back than road cleats other than Speedplay allow.

I have three reasons for believing this:

1. Firstly, the calf muscles have to control the lever that is your foot from its hinge at the ankle to its attachment at the pedal. If you reduce the length of that lever, you reduce the energy wasted on your calf just keeping your foot stable.

2. Secondly, the bigger (heavier and stronger) the person, the harder they will push through the small interface between the pedal and the cleat. This larger force goes through the same tiny area of interface as a lightweight rider, but it puts way more stress on the metatarsals of the bigger, stronger, heavier person’s feet, leading to more “hot foot” pain if the cleat is located at the ball of the foot, and, in some cases, results in neuritis or neuroma between the joints of some of the metatarsals.

3. Thirdly, since you essentially shorten your leg length from the hip to the cleat by moving the cleat further back on the shoe, you can run a lower seat height with a more aft cleat. This results in lower aerodynamic drag and improved cornering due to a lower center of gravity, not to mention the possibility of a smaller frame size if you are in between sizes.

These are the reasons that I personally use Speedplay pedals; I have my cleats all the way back on the Speedplay cleat-extender base plates. You substitute these aluminum offset cleat-mounting plates for the standard plastic base plates; they allow you to position the cleat 2mm further forward than the standard plates or (and here’s their key feature) 14mm further rearward. Light Action, Zero and X Series only.

Mountain bike shoes already allow almost the same cleat position as Speedplay road pedals with the cleats all the way back on the cleat-extender base plates. Simply use the more rearward pair of holes in the shoe’s mounting plate and push the cleat all the way back.

I think people with big feet will immediately experience a sensation of being able to push harder on the pedals, if they have their cleats a centimeter and a half further back than most road shoes and pedals allow. I can’t speak for people with small feet, since I don’t have those. All customers of mine getting a full fitting who have feet larger than size 45 leave here with their cleats as far back as I can get them. After all, I doubt that King Arthur pulled the sword out of the stone with the ball of his foot on the stone; rather, to yank most powerfully while pushing hardest with his foot, I’ll bet he planted the underside of his longitudinal arch against that stone.

Incidentally, I have tried the extreme version of this: riding with my cleats right under the longitudinal arch of my foot (with my tibia directly in line with my cleat). So that I could experiment with this, Don Lamson made me a pair of custom, carbon-soled road shoes with two sets of three-hole cleat mounting inserts — one in the usual area under the ball of the foot, and the other in the middle of the longitudinal arch. While I found that this felt very powerful for climbing and it allowed me to lower my saddle by a full 3cm (!!), it felt too tippy for my comfort when standing out of the saddle. Also, some riders would have huge pedal-overlap issues with the front tire.
― Lennard