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The Hardest Front Derailleur I’ve Ever Confronted; And How I Vanquished It!

November 2020
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I run a Shimano Sora drivetrain on my gravel bike. 2×9 sp., 48/32 up front, 11/32 in the back. I had to compromise buying the bike because I bought one for my wife at the same time. We simply couldn’t justify laying out the cash for two high-end gravel rigs when we really didn’t plan on using them in a manner that would require a high-end steed. That is, until a couple of my friends whom I can normally hang with put a hammering on me on their high-end horses. It was only then I thought, “I should have known better! Why, oh why didn’t I buy a better bike?!”

Whatever, it’s water under the bridge. I have to work a little harder to keep up, it is what it is.

That said, the Sora Drivetrain was a nice surprise. I was expecting something well below the quality of the 105 line on my Trek and the Ultegra on my Venge. The shifting and overall feel of the drivetrain is exceptional. I never thought I’d write that sentence.

It wasn’t all fun and games, however. Since I brought the Diverge home, the front derailleur gave me fits. At first, I thought there was a noise from the chain rubbing the derailleur, both at the big and little gears. Getting the cage to handle all of the gears was not easy – but I always assumed whoever set it up at the shop got the set screws right, and you never touch the set screws so it had to be a barrel adjustment issue, right?

Wrong. I spent the better part of a season (which sounds long, but really isn’t, I only put a few hundred miles on the bike the first year) monkeying with the barrel adjusters hoping I’d be able to luck my way into getting it right. I could get it close, but there was a rub when I trimmed the front cage for the two smallest (hardest) gears, then chain rub on the biggest gear without the trim.

That’s where this gets fun.

I’m going to condense two years of consternation into two paragraphs, but keep in mind, being only a junior bike noise sleuth in good standing, it took a minute to figure all of this out – and it wasn’t until I decided I had to play with the set screws that everything finally came together.

The first problem was that the chain wasn’t rubbing the front derailleur cage in the two smaller gears, with the cage trimmed. It was the crank arm that was hitting the cage when it was trimmed all the way out. The trick, then, was getting the derailleur cage in, toward the chainring, but not too far it that it would rub the chain. As it turned out, there’s a fine line between the two. A very fine line.

How fine? You can’t measure the clearance in millimeters. Tenths of millimeters.

Now, this crank requires a wavy washer, so technically, because the wavy washer is for preload, I could install the washer at the drive side. This would push the chainrings and crank arm to the right and allow a little more clearance for the cage at the crank arm. But, that thinking is a little flawed and, as you can see, I made it work. Barely.

In the first photo, you can see I couldn’t fit more than a business card, folded in half, betwixt the crank arm and derailleur cage. The second photo shows the clearance for the chain. Again, not much… but enough.

When it comes to set screws, I tend to create more trouble than the problem I fix, so rather than mess with this with YouTube videos, which are great, but tend to lack the finer points, I went straight for the Shimano front derailleur installation manual. The manual shows precisely how to install a front derailleur properly – and if you use the full install instructions from the beginning, you don’t have to worry about narrowing down and fixing a flaw, you just set the derailleur up correctly. The instructions start on page 10. I read through them once, then did everything, step-by-step, using the manual as a guide… and a short while later, I had the derailleur set, perfectly. After that it was just a matter of tinkering to get it dialed in so everything worked without rubbing. And Bob literally is my uncle.

And so there it is, the perfect setup on my Specialized Diverge (mine’s the one with the red helmet hanging from the shifter lever.

The main thing I learned through all of that is, the shop’s mechanics aren’t always perfectly right, and I can be if I seek out and follow the proper instructions.

Unless we’re talking about a suspension fork… in that case, it’s going to the shop. That’s a period at the end of that last sentence. Some $#!+ I just don’t need to get into.


8 Comments

  1. The Omil says:

    My best equivalent was when I had the ‘spare’ end of the front mech cable clicking against my shoe.

  2. Dan says:

    Front derailleurs are ALWAYS harder to set than rear!! I’m having an argument with my wife’s 105 tripple!!

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