Shimano XT vs. SRAM X9 Clutch Derailleur Systems

Products: Shimano XT and SRAM X9 Clutch Derailleurs

Shimano XT

10 Speeds

Weight: 258g

Tested on: Specialized SX Trail; Turner 5.Spot

MSRP: $140

 

SRAM X9

10 Speeds

Weight: 250g

Tested on: Specialized SX Trail

MSRP: $116

 

When 10-speed drivetrains for mountain bikes came out I, like a lot of other people, thought, “Meh, what does one more gear really do for my life?”

After all, a lot of us are old enough to remember when 9-speed systems came out, and the crappy early chains that came with them that left our crotches on our top tubes when they would break under a sprint.

And a few of us are even old enough to remember when 8-speed systems came out, and buying new hubs sucked, and all we got was another reason to pedal uphill slower.

And some of us are just old grumpy bastards who hate new stuff….

But then something interesting happened: friction clutches on derailleurs.

Chains on multi-speed mountain bikes flop because of derailleurs, simple as that. Derailleurs act as tensioning devices, and there’s a degree of freedom dictated by the strength of their spring. Regardless of what an engineer at Shimano or SRAM comes up with as an acceptable balance of shift resistance and “flop retention” (no, seriously—that’s an industry term), there are going to be multiple scenarios where you and I are hitting sections of trail that shake that little derailleur cage all over the damn place.

Chains are steel. They’re heavy. It takes a lot of spring tension to keep them from bouncing. But what if we used a damping system based on friction instead of just raw spring tension?

Eureka! The paint on your chainstay is saved! And more importantly, you can now silently sneak up on dudes in thin, ripstop short shorts speed walking with power poles.

This more than anything else piqued my interest in 10-speed setups (the dudes in short shorts I mean). And I’m far from alone on this. The conversation of 10-speed clutch derailleurs being used with 9-speed systems has become a pretty common one. As in, “I want a clutch derailleur, but why should I spend all the money on additional shifters and a cassette?” Hold tight, I’m about to tell you why. Because it’s really the biggest reason to switch to a 10-speed setup.

The Crappy Part

With 10-speed systems comes a new parallelogram from both of the big two that moves the derailleur in an entirely different way than 9-speed systems. I tried it. It “kinda works,” at best. As in, I’d be fine getting out the woods with it, but there’s no way I’d roll a bike out of my garage with a 10-speed derailleur with 9-speed shifters and cassette. Skipping your chain sucks and causes boo-boos. You will end up with a crippled bike if you try this. Don’t do it.

If you remember the first wave of 9-speed chains, guess what! 10-speed chains bend easier, too! I measured some plates of 9-speed links and 10-speed links, and they’re the same thickness as far as I can tell (about 0.95mm). The only thing I can think of is that the 5.75mm width of an entire outer link (vs. 6.50 for a 9-speed) is less structurally sound with regards to lateral forces. It’s like taking a bowlegged cowboy and making him stick his ankles together. That ain’t no fightin’ stance. Just narrowing the chains in itself makes a weaker parallelogram…it’s science. It may not be the plates themselves, but I do know that the first 10-speed setup I had experienced two bent chains. I don’t even know where or why it happened. I don’t remember anything unusual in a shift, but my chain started skipping. When I went to see what was going on, my chain was bent…in both instances.

A good friend of mine who is one of the most technically proficient bike riders I’ve ever met actually bent one in a race on a course he literally used to live at the bottom of. Neither of us bend chains. When we went to 10-speed setups…we bent chains. I’ve been a little more conscious of my shifting, and it hasn’t happened again, so we may have just been riding like hacks. But I’m convinced there’s something going on with the narrower chains and/or the tighter gear spacing that makes this a potential issue.

If you’ve ever ridden a dialed road bike with tight gear spacing, you can appreciate the small gaps between gears. It just feels so much more smooth and refined. Riding road bikes is boring, however, and it leads one to geek out on mundane things like “smooth, tight gearing.” When I shift gears on a mountain bike, it’s because I want a significantly different amount of resistance—and soon. I actually find the tight spacing kind of annoying, and the thought of dammit, gimme another! is kind of a regular occurrence.