Road Bike Drivetrains, Cassettes, Chains, Cranksets… and Annoying Noises; Shimano, SRAM and ShRAMano
Two weeks ago I had a cassette on my Trek 5200 that Dr. Frankenstein would have approved of. The three bottom (big) gears from SRAM cassette and seven of the top gears from a Shimano 105 cassette. This was the only combination that allowed my bike to shift (relatively) normally up and down the cassette. I spent the better part of two years messing around with the setup thinking the problem was in the cable network – that there was drag in the system due to an error on my part. The bike displayed classic symptoms of systemic drag problems… trouble shifting in one, maybe two gears, but only up or down the cassette (rarely both), unless it was perfectly dialed in within an eighth of a turn on the barrel adjuster. If I had to guess, I’d hit about 85% of my shifts crisply and cleanly. I’d get a hesitation in 10% and completely miss 5%.
The problem turned out to be a worn-out rear derailleur.
With a new derailleur, it didn’t take long to realize it might be better if I went with a single-line cassette. There was a slight misalignment between the third and fourth cog that would produce an ever-so-slight chain skip click when in that fourth cog. Fifth? Third? Absolutely quiet and all of the other gears were awesome. Now, it must be stated here, I am intolerably finicky about such things. I can’t help it. I’ve sought counseling. The counselor pulled all of her hair out. It’s not good.
Anyway, going by Shimano’s and SRAM’s instructions, both companies recommend exclusive drivetrain compliance – in other words, no ShRAMano. I’ve been mixing SRAM chains and cassettes with Shimano components for years, typically because my LBS stocks them (I still shop for everything the shop stocks, there). In many cases ShRAMano will work just fine, but mixing the cassettes was a touch much. I knew this going in, but if one has to resort to mixing cassettes, something is wrong in the drivetrain that needs to be corrected. That “needs to be corrected” part weighed on my mind. I don’t like “needs to be corrected”. My counselor* will attest.
The shifting with the setup above was close, but left a lot to be desired. Every gear shifted excellently except the second to the largest cog. That gear, if I didn’t do a hard shift, stuck downshifting (going up the cassette) and it sounded like the chain was going to grind to dust any minute. It worked fine upshifting (going down the cassette to a harder gear).
Now, I know what you’re thinking, something is still wrong with the shifting – perhaps there is drag in the cables? That’s the typical answer. I investigated that. On a fluke, I took the Shimano Ultegra cassette from my Venge and put it on the Trek, then put the SRAM PG1070 cassette on the Venge. The Trek shifted like butter, 100% up and down the cassette. Not one missed shift. So, I know what you’re thinking… the Venge now shifts like crap now. Nope. 100%, without a noise. I rode the Venge on Tuesday night hitting every shift with precision and crispness – 100%. In fact, I’m actually looking at this as a win-win – the Venge shifts better with the SRAM cassette than it did with the Ultegra (and with Ultegra components, no less). And the Trek appeared to be right as well, finally.
I took the Trek out for its first test spin last evening and it was fantastic. Not a single missed shift or extra click with the chain moving to the next gear, up or down in either the big or little ring up front. It’s been a long time coming, but I’m finally done with this mess. Well, almost done. I’ve got a new Ultegra chain on the way, too. I was going to need a new chain pretty soon anyway (guessing, right around DALMAC time) so I may as well slap a chain that matches the drivetrain on the bike. That seems to work on the Trek. For the Venge, I’ll stick with ShRAMano.
How do we make sense of this? Hey, I wish I could tell you. Sometimes ShRAMano works, sometimes it doesn’t. Supposedly, it’s always best to stay within the line… though, it appears, not necessarily in every instance. Flip a coin.
*I didn’t actually meet with a counselor about how my bikes shift. I talked about it with my wife a little bit, but all of her hair remains firmly attached to her head. I used the line to be funny and overly melodramatic. If you didn’t get the joke, or were offended, well that is unfortunate. I have sought counseling for other matters both related and not related to what I’ve written about on this blog (the overall blog, not this post), so your petty attacks won’t work on me. I wear my issues on my sleeve and write about them often with the sole hope of helping others. If you can’t take a joke, that says more about you than it does me.