Technical FAQ with Lennard Zinn: The inverted link

A reader makes a minor change to his drivetrain and experiences a whole new set of problems. Is there a simple solution? Lennard Zinn thinks so.

Dear Lennard,
I am running Campagnolo Record 10 speed with a Wippermann chain and have never had any issues until I changed to 53/39 ROTOR chain rings (oval). Now when I get up on the pedals and really apply hard pressure to pedal, I get what seems to be the chain skipping? Not “mystery shifting” just skipping. Could my chain be too short or too long? The mechanic at the bike shop said I probably needed a new cassette, but I wasn’t having this issue until I changed to oval rings.

Make sure that the ConneX master link is not inverted.

Dear Ron,
As always with a Wippermann chain, I would first check to make sure that the ConneX master link is not inverted. It happens all of the time. As you can see here, one side of the link is concave and one is convex (i.e., it is taller above the connector hole). If you let that convex, or taller, edge be facing your cogs, it will lift the chain out of the tooth valley wherever it rides up on the spacer between cogs. On most cogsets, this only happens on the smallest cogs, but on machined SRAM Red cogs, this high spacer situation exists between every pair of cogs, so you will get skipping on every cog.

Orient the ConneX master link so that its taller convex edge is away from the chainring or cog. Another way to think about this orientation is to notice that the pair of connected holes on each plate (into which you push the pin) forms a heart shape. When the chain is on the top of the cog or chainring, make sure that the heart is right-side up. Either way will ensure that the taller, convex link edge is facing outward from the chain loop.

Since your mechanic blamed it on worn cogs and not a worn chain, I’m guessing that he replaced the chain, making this inverted link issue a likely cause.

As for other causes, I’m assuming that the cable tension is dialed in on the rear derailleur so the skipping is not from trying to jump to an adjacent cog. Otherwise, a chain that is only moderately too short or long should not cause skipping, nor should the oval chainrings. And while it is certainly possible that your cogs are worn, I, too, would wonder why it suddenly coincided with the chainring change. But you can check the cogs for wear. If you have access to Rohloff’s “HG-IG-Check” cog-wear-indicator tool, wrap its measurement chain around the cog (while the cogset is on the freehub) and pull on the handle. If the last chain roller on the tool hooks on the tooth and resists you flipping it in and out of the tooth pocket while the tool handle is under pressure, or, worse, if the entire measurement chain except the first roller slides easily away from the cog teeth while the handle is under pressure, the cog is worn out. The tool only works on cogs up to 21 teeth.

Dear Lennard,
I installed a new Campagnolo compatible freehub body onto my Mavic Ksyrium Equipe rear wheel today. Upon installation of the cassette (Chorus 11s) and tightening the lockring (only finger-tight) I found the largest cog rubbing against the flange of the hubshell. The inboard side of the cassette seems to be flared out in a way that causes this contact between the largest cog and the flange.

I double checked the packaging of the cassette for a spacer, but found none. I checked Sutherland’s 7th Edition for info but it is only updated to Campy 10s. I talked to another mechanic at a shop and they’re stumped. I thought maybe Mavic is making 10s compatible freehub bodies and a separate freehub body that is 11s compatible.

Dear Peter,
You need to get Mavic’s ED 11 spacer or an ED 11 freehub body with that spacer. This spacer is a 0.55 mm spacer that just slides onto the freehub body behind the cassette. This will bring the cassette away from the hubshell enough to clear it.

Since November 2008, all Ksyrium Equipe Campy-compatible wheels have been built in this ED 11 format instead of older ED 10. Additionally, all Mavic freehub bodies sold as spare parts are only available as ED 11 now too. (If you don’t need the spacer, just take it off.)

The only difference between Ed 11 and ED 10 is the spacer.

Yours is probably an older freehub body that didn’t have that 0.55mm spacer.

Bike shops can call into Mavic customer service to order spacers.

Dear Lennard,
I have recently obtained a road frame with short horizontal rear dropouts on it, and I am having issues with the wheel slipping when I start from (let’s say) a stoplight. I do have a quick release on it and I am using the dropout adjusters. I have also used a shim that did a similar thing but it still seems to slip. The only other thought was to use a bolt-on style hub but that is not something that I want to do. I was hoping you might have an answer about something that I could do.

Dear Andrew,
Make sure both the end faces of your outer axle nuts and the inner faces of your quick-release skewers have teeth on them.

If that alone is insufficient, get these. With these DT Swiss RWS, you can take the wheel out just as fast as with a QR, but they clamp harder. And with many cartridge-bearing hubs, you can replace the axle with a 10mm DT Swiss RWS, and then it will really clamp hard.

Dear Lennard,
After an incredibly wet ride recently I dumped a couple of ounces of water out of my chainstays. This is a brand-spankin’ new, high-end, brand-name steel frame and has, what I assume are vent-holes from the manufacturing process at the top-inside and bottom of the seatstays and at the rear of the chainstays (where the water came out) and near the top inside of the forkstays. The bike is drying out in my basement.

Do these holes serve a purpose anymore (other than a convenient drain)? Should I seal them? I have a new-technology Campagnolo bottom bracket and am also worried that this may have been somehow corrupted in the recent deluge. Any suggestions?
Slowlearner (Tom)

Dear Slowlearner,
Yes, those are vent holes. If the frame didn’t have them, the framebuilder could not have gotten good flow of brass around the dropouts and into the fork blades, chainstays and seatstays, since air pressure would have kept pushing the brass back out. And on tubes completely welded at both ends, vent holes allow the builder to close the welds entirely without having them blow out when reconnecting with the starting point on the last weld (or suck back in when he/she pulls the torch away, if he/she managed to blob enough welding rod on there to keep the hole closed).

The vent holes serve no further purpose. Go ahead and seal them. We always seal our vent holes in chainstays, seatstays and bridges (and fork blades, in the rare instance when we still make a steel fork anymore) by welding or brazing them shut after everything is done and has cooled.

In your main tubes, there’s no way to close those vent holes off that go between tubes. Pull out the seatpost and bottom bracket, let it dry out, and spray JP Weigle’s Frame Saver into whatever tubes you can. With the little tube that plugs into the spray cap, you should be able to get into all of the tubes except the seatstays (after you’ve sealed your vent holes, that is) and the head tube (and you can pull your fork to get in there; just wipe grease inside of that one).

I also highly recommend drilling a drain hole in your bottom bracket shell as close to the lowest point of it as you can, adjacent to your plastic cable guide (use it as a guide for your drill bit). This keeps water that is thrown up by your rear wheel that goes into the slot at your seat lug and flows down inside your seat tube from just building up in the bottom bracket shell and bottom of the seat tube. You can ruin your bottom bracket from the inside as well as rust it firmly into the bottom bracket shell if you don’t let that water out. I actually think that drilling a drain hole in the bottom bracket shell is a good idea for any bike, including ones that don’t oxidize, like carbon and titanium frames. After all, the bottom bracket bearings and races are still steel, as are often the cups and spindle.

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Technical writer Lennard Zinn is a frame builder (, a former U.S. national team rider and author of numerous books on bikes and bike maintenance including the pair of successful maintenance guides “Zinn and the Art of Mountain Bike Maintenance” – now available also on DVD, and “Zinn and the Art of Road Bike Maintenance,” as well as “Zinn and the Art of Triathlon Bikes” and “Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists.”

Zinn’s regular column is devoted to addressing readers’ technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn. Zinn’s column appears here each Tuesday.