Tuesday, December 12, 2017

Another 1x11 review

This year I swapped both my mountain and cyclocross bikes from 2x10 to 1x11 drivetrains. Like I mentioned, this is simpler, lighter, easier to use, and tends to keep the chain in place better with the big chainring teeth and clutched derailleur. And like I did with the mtb drivetrain, I figured I should get a little use out of the new cx parts before giving it much of a review.




I collected these parts from various places (some stuff from Missoula Bicycle Works, some stuff from the internet, and the chainring from a friend), and had it installed just in time for week 2 of our Wednesday night series. With Rolling Thunder, it's seen use in 6 races plus some general riding for a total of 600 miles. I think that's enough time and I've been out in a good variety of conditions- racing on a few different courses, riding on pavement, dirt, gravel, up hills, and even some time out on singletrack. Like with the MTB, it's a big improvement over the previous setup with a front derailleur.


The main issue I have with the mtb drivetrain is the shortened gearing range. It's a little tougher on the low end, and runs out up top. However, the 2x gearing on my cx bike was really narrow, so with a wider 11-32 cassette instead of 11-25, I was able to ditch a chainring and front derailleur with no loss in total range at all. That's really the trick to this whole 1x thing- instead of more gears up front, they use more on the back. My old Shimano 105 derailleur was only meant to be used with an 11-28 cassette. With the new Sram Apex derailleur, I can use a 10-42 if I want. Why is this such a big deal? Well, there's the weight and simplicity and better chain retention, but more importantly, a rear derailleur will always shift faster, more smoothly, and better under load. This is because the chain is being moved on the untensioned side of the cassette, and the gaps between the gears are much smaller. A front derailleur, on the other hand, has to deal with a big 10-16t jump plus any tension put on from pedaling, so it's never going to be as smooth, as fast, or as reliable, regardless of electric motors or syncro shift wizardry (and I have a bike with a di2 front derailleur).

That said, I didn't really have many problems with the old front derailleur. Having closer spaced cx rings (46 and 36) does improve front shifts. So why am I doing this again? Well, 36x25 was pretty hard on those long hills, and I like to simplify and add lightness. While the difference between my shortest and tallest gears didn't change, it is shifted down to be a little easier with a smaller 42t chainring. On the top end, there's still enough to pedal at 30ish or so, and now it's a little more comfortable on long climbs. I would have even considering going lower with a wider cassette and/or a smaller chainring, but cost was a factor. As I got the chainring used from Cory and the 11-32 cassette was only $35, going with different gearing was going to be another $70 or so. 42x32 is still not mtb gearing, but it gets me up things like snowbowl road and butler creek a little easier, and I even rode it up the ravine trail although another gear or two would have been nice on that. And then it's tall enough to make it through Wednesday Worlds (if I didn't have a road bike).



Alright enough gearing nerdery. How's it work? Well, pretty good. With the sram shifter there's only one lever. The first click and release gets you an upshift down the cassette, and if you push the lever past that to the next click, it downshifts. You can downshift three at a time. A full sweep of the GX mtb lever will get you 5 shifts, which combined with the much bigger gaps in an 11-42 cassette, gets you a really big change of gearing fast. Having a front derailleur does the same thing- You can pedal into a ride-up in the big ring, and then drop to the little ring when you run out of speed. With the 1x I have to sweep the shifter, sometimes more than once, all while trying to pedal up a steep hill and pick my way through rocks, logs, and other racers. It's easier to wind up in the wrong gear and might make it more likely to drop, break, or jam up a chain. When you look at the pros, there are still quite a few racers using a double, probably for this reason. It's also true that shimano doesn't offer a clutched 1x setup for cx, but with di2 you can just use a mountain bike derailleur. Or maybe that is not an approved setup for the sponsored racers.

That's one downside- it takes longer and more effort to dump a lot of gears. I suppose a wider range cassette would improve that slightly and give me easier climbing gears, but then there is the worry about big gaps. 11-32 is a pretty close ratio cassette for 11 speed and I don't really notice on the road but 11-36 would probably have been a better choice.

Whoops, there I am talking about gear ratios again. So anyway, I did have an issue with it but I appear to have fixed the problem. Sometimes the shifting was not quite perfect. This problem would only come up with multiple downshifts. The first shift, fine, sweeping all the way across for 3 gears worked, but getting two shifts was sometimes be an issue. I needed to go just a little bit past the click to get it to actually shift. I fiddled with tension, made sure the cable was sliding smoothly, and even shortened the little bit of teflon liner where it went through the guides.



I even considered the possibility that the cheaper apex group just doesn't work as well as the nicer stuff. Yes, apex, rival, force, red, all have pretty much the same shifting mechanism, just with fancier materials on the more expensive stuff, but I still wonder if there's anything different besides materials.

I also had an incident where I crashed in a sand trap in a race and got the shifter completely packed full of sand. I did clean it out pretty well but a few grains here and there could definitely have an effect on the shifting.



So finally, after the first trainer night of the winter, I was able to pay a little more attention to what was going on in a controlled environment, and decided that my b-limit was just a little too far out. I would up just removing the screw entirely to get close to the recommended 6mm of clearance. I'm not sure if it's because the derailleur is designed to handle a much bigger cassette than I'm using or if it has to do with the frame/dropout, as I had to have the limit really far out on the old drivetrain too. On the plus side that saved some weight and it shifts properly now. B-limit adjustment seems to be a little overlooked but I've found it pretty important for good, smooth shifts, and I seem to always find mine too far out for some reason...
I suppose the conclusion here is that a 1x setup is almost always a good upgrade and I'm really liking it on both the CX and MTB. On those long forest road climbs I appreciate the new gear range and it's easy to change with a different cassette or chainring. It also dropped enough weight to be noticeable when riding, putting my bike at just under 19lbs when it was over 20 new.

Well I guess that covers it. A set of decent wheels for this bike and it will be even lighter and good to go for at least a few more seasons, which is good because a new CX bike is not on my radar at all. "Oh no, it does't have disc brakes," you say. Well, on a race course, and even riding down singletrack the new mini-vees work just fine. or much better than the old cheap cantis anyway. The head tube's not slack, and the bottom bracket isn't low like newer bikes, but for racing that's not really important. Geometry chainged on newer bikes I think to make them more suitable to riding on gravel and stuff. But it's a cyclocross racing bike, not a gravel bike. Wait, there's a difference?  Anyhow, a little money spent on a new drivetrain and brakes has made this bike a lot more enjoyable to ride, so I'm going to keep doing that.



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