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Cycling with Friends: Part 6,491

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Perfect Shifting on a Shimano 10 Speed Drivetrain Requires Perfect Cable Housings, Ferrules, and Fresh Cables

I’ve written before, in a disjointed “update” fashion, about my adventures with Shimano’s 10 speed shifting problems but after yesterday’s adventures, it’s time for a full post. Necessity is the mother of fixing a road bike’s drivetrain is how the saying goes, methinks.

First, Shimano’s 10 speed drivetrains (105, Ultegra, Dura Ace) are notorious for poor shifting quality if there’s any drag in the cable system. And by “any”, I mean any. No drag? Fantastic. Drag? Read on… I won’t be dealing with the normal culprits in this post, things such as dirt, grime, wear, excessive lube, installing the cable improperly on the pinch-bolt of the derailleur, frayed cables, sweat and sport drink-caked cable guide, etc. This post is for a more nefarious issue.

If you’ve got drag in the cable system, here’s what it will present as, in two different scenarios – each on a different bike, with a different component line (Ultegra and 105).

With the first, you can get the shifting dialed in, but it’s hard. One quarter-turn either way and it’ll shift good going up the cassette or down the cassette, but not both. You’ll get a hesitation on one or more gears while others will work just fine. If, however, you get the barrel adjuster dialed in just right, it’ll shift perfectly. It’s liable drive you up a wall, too, because the cause can be tough to track down – it was for me.

In the second scenario, and worse, you’ll get clicking gears, almost like you’re half-geared, going up or down the cassette, but not both. Motherf****er, I’m getting worked up just thinking about it. It gets worse; it’ll happen on specific gears only, upper, lower or middle of the cassette depending on which way you’re adjuster is misdialed. Oh, it gets still worse. You can get it dialed in just right in the big ring, but it’ll click in a couple of gears when you shift to the little ring. We’re going to deal with this scenario first, because it’ll drive a person mad. It did me.

The clicking problem presented itself on my Specialized Venge. Shimano Ultegra 10 speed. I switched housings, cables, almost everything and couldn’t find the damned gremlin. Then I gave the mechanic at the shop a crack at it. He made it better by installing new cables all the way back, but I still had to have it dialed in just right… and I still had the big ring/baby ring problem, though as little time as I spend in the baby ring, it was livable, at least. Still, it bugged me to no end knowing there was something off.

In the end, I got lucky finding the problem. The mechanic at the shop ran the rear derailleur housing exiting the handlebar and entering the down tube about a centimeter too long. It drove me nuts seeing it not symmetrical with the other side. I decided to tinker with it one Saturday to get that cable length corrected. When putting it back together, the ferrule (end cap) was a coated plastic… I didn’t like it and swapped it out for a metal end cap before putting everything back together. After HOURS of monkeying around with it, shifting perfection was achieved at long last. It was that one little freakin’ plastic ferrule that gummed up my shifting so bad, a pro couldn’t figure it out.

Second up is the hesitation in the shifting on my Trek, Shimano 105 ten speed drivetrain. Now this was a little trickier to pin down for one fun reason. The whole bike, from the ground up, is new except for the frame, fork and chain ring bolts. I chose the cable housing lengths myself, based on a guess. I threaded the housings through the handlebar ports. I put it all together myself, brakes, shifters, housings, end caps… all of it.

So let’s just say there was a lot I could have messed up and leave it at that.

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I checked everything and was simply flummoxed. No plastic ferrule, no bad housing, no drag in the system… in fact, I went so far as to leave the rear loop alone because if it worked on the old 9 speed system, why mess with it, right?

Guess what I found out Sunday night? Yep, it was the rear loop that worked perfectly on the original 9 speed system. It was the only thing I hadn’t changed and before I messed around with changing new stuff, because I’d finally had enough, I just wanted to make absolutely sure. I cut a new length of shifter housing (there’s a difference between brake and shifter housing, by the way) and put two brand spankin’ new end caps on each end, threaded it on, connected the cable to the derailleur, dialed it in with the barrel adjuster… et voilĂ . Doh! Perfect.

The problem inherent in the ten speed system was corrected in the eleven speed drivetrain. The fix for a ten speed system can seem complex, but with a little sticktoitiveness it can be dealt with. The tough part is figuring out where the drag is in the system.

If, by some unlucky stroke, you run into this on your bike, the best advice I can give is run the whole cable system new back to the derailleur. New housings, new cable, new end caps (and be sure to use metal caps)… no frayed ends on the shift cables, too. The problem is drag on the cable, even the slightest little bit will throw the system off, so I wouldn’t use a heavy lube on the cable, either. In fact, if you’ve got decent housing, I’d stay away from lube altogether. Modern shift cable housing doesn’t require it, though check the manufacturers instructions for yours, just to make sure.

This post assumes, of course, that all other issues are dealt with, like a gummed up cable guide (under the bottom bracket shell), the cable is on the proper side of the pinch bolt, the cables aren’t frayed or rusted, the housings aren’t gummed up, etc. etc. etc.