Monday, August 14, 2017

Sram GX 1x11 MTB drivetrain 1000 mile review

This spring, I finally caught up with the rest of the world and got rid of the front derailleur on my mountain bike. Now I've got some good miles and a few races on it and thought I'd write some more words. I see way too many reviews of stuff that consists of "hey check out these new parts, looks cool, right?" Well, try it out for an extended period of time and get back to me. So that's what I've done, and the conclusion is that it's pretty good.



I used the following parts:

Sram GX 11-speed shifter
Sram GX rear derailleur
Shimano XT 11-42 cassette
Shimano HG-601 chain
One-up 32t sram direct mount chainring
Total cost was around $260.

GX is one of Sram's cheaper 1x offererings, sitting above NX, and below X1, X01, and XX1. There is also now a 12-speed eagle version of GX which is very well priced. I went with these parts because I was on a budget, and GX is the least expensive level that offers "zero-loss" shifting. This means there is no free play in the levers before cable moves. I tried the NX shifter, which does not have that feature, and could notice the extra movement in the lever before it shifts. The GX part feels good and shifts are crisp and instant. Coming from my di2 road bike I actually don't even notice much difference, although sometimes I find myself holding down the upshift paddle, expecting it to keep going. An NX rear derailleur would have saved a bit of money with probably no change in function, but the GX part was barely more expensive (about $30) so I thought I'd have it match. Making the jump to X1, the next level, however, would have cost way more; MSRP on an X1 shifter and RD is an extra $155 but as far as I can tell it's functionally the same, and the listed weight saving of the two parts is only 10g. So no thanks. X01 and XX1 are even more and I just can't justify that kind of $ per gram of savings.

And yes, I mixed shimano and sram, for two reasons. The XT cassette is way less expensive than a Sram equivalent (only $65 online, sorry MBW), and it works on my freehub. When I toasted one awhile back I tried to find a Sram XD driver but Easton doesn't make one for my wheels, since they were made all the way back in 2012. But still, I wanted to use a sram shifter and derailleur because I like them, it matches the rest of the stuff on the bike, and the brake lever and shifter go on the same clamp which is nice and clean looking.



I moved the the fork lockout, which is built into the clamp, to the other side so that I wouldn't have three things coming off the right side and just a brake on the other. I'm considering going to a non-remote lockout compression damper to clean things up even more. And when sram comes out with e-tap for mtb and cx bikes that will be really nice.

My cranks (sram X9), use a removable spider to attach the rings, so I was able to just remove that whole thing and put a ring straight on. Way less stuff, way lighter. The single ring compared to the spider, ring, bolts, shifter, derailleur, cable, saves 430g. That's like a whole pound off the bike.


So, I simplified, and added lightness. There is only one downside, and that is the narrower gearing range. Before, I had 26/39 x 11-36. To get the equivalent range with a 1x I would have needed sram's new 12-speed eagle. A 36t and 10-50 cassette works out nearly the same. This loses out on both ends, with 32x42 being equivalent to 28x36. I think most 2x cranks use 24/36 rings, which makes what I have fairly tall, but it works on a light XC bike. On the other end, above 25mph there's no point in trying to pedal anymore, which doesn't really come up out on the trails, but coming back on the road I do spin out..

There are a few ways to get more range out of 11s. Firstly, the sram XD freehub with a 10t little cog. 30x10 is taller than 32x11, so I could have used a smaller chainring without losing out on the top end. But no such luck with my wheelset. Another option would be Shimano's 11-46 cassette, but I was worried about the big jump to that cog, since the next smallest gear is the same size, 37t, on both. I find myself going up onto the 42 under load pretty frequently and even that takes slightly longer to catch compared to shifts in the middle of the cassette.

The lack of range, however, is more than made up for by how well it works, and the ability to ditch the front derailleur. With the old setup, I would experience chain suck, shifting problems, occasional dropped chains, and noise from the chain hitting the chainstay. The narrow wide chainring and clutched derailleur hold the chain in place much better, so the drivetrain is silent and the chain always stays in place. And despite GX being the budget group, shifting performance is excellent. I would challenge anyone to say XX1 feels or works any better.

If you still have a front shifter on your mountain bike, I'd strongly suggest getting rid of it. This is old news I suppose, but I only just got around to it and still see plenty of them around. I accept that there are still some cases where a front derailleur is useful, like bikepacking/touring, but now that we have 12-speed 10-50 cassettes I'm not even sure about that. The only caveat is that you need to do a little gear-chart math and be realistic when choosing a chainring size. If I was riding a heavier, full-suspension, more trail oriented bike, I would definitely want easier gearing.




Thursday, August 10, 2017

Mountain Bike Season

Road racing season came and went pretty quickly, and the summer has had me wondering about my choice to buy a new road bike this year as opposed to spending that money on MTB and CX stuff. A full suspension bike sure would be sweet and the cross bike could use a new drivetrain and some wider, tubeless-ready wheels. But no, not really, because I like road riding and it's an awesome bike.

Anyway, my Kona could use some fresh tires and a brake bleed but is otherwise in pretty good shape, especially with the new 1x11 drivetrain and recent fork service. I noticed that using buzzy's slick honey instead of the liquid o-ring stuff in the air shaft significantly reduces stiction and the bit of extra travel helps smooth things out too. It could use a nicer compression damper though.

This year I was looking forward to racing Missoula XC, and wanted to be in good shape for it. Unfortunately, I crashed in warm up for wed night racing the week before and banged up my elbow pretty bad. I wound up sitting out the racing again (last year I hurt my foot), but did go help with the course setup and had a good time hanging out and taking pictures. A few of us camped out after the race which was a good idea due to all the free Big Sky beer. Whisky might have also made an appearance. Here are a few pictures I took:








Speaking of the wed series, they did away with the cat 1/2/3 this year, instead just having open and beginner categories. So for me that meant racing with everyone fast. I think I managed to come in around 10th most days which was acceptable, but my riding kind of fell off going into June, then I had to take some time off with the elbow, and so I haven't been getting the time in on the bike I would like. But I guess that's okay as it gives me a break before CX season.

The first couple Wed races were at the XC course, doing various loops up at Marshall. Two days incorporated the new trails higher up which meant a whole bunch of climbing. Week 2 I was definitely hurting on the way up, but it was called short after a lap due to thunderstorms, which was nice. I need to lose like 10lbs for this next year because climbing straight up for 1500ft is all about power:weight ratio, so every bit helps.

The 4th week, at Blue Mountain, was postponed due to weather, so my elbow was feeling good enough to race. The race went pretty good for me although I need to work on descending a bit more. Fresh tires and a dropper would be useful. I was climbing pretty well but lost a good amount of time to a few people on the way down. But with all the loose dirt and rocks out there I'd rather stay upright and keep air in my tires over setting downhill PRs, and I did manage to do that. There was a lot of attrition as I went by 2-3 guys with flat tires on the first descent, and I got to the top of the hill pretty near the front. Then I had a good race chasing Evan and going back and forth with Garrett.

I missed the final week at snowbowl and the two WM trail series summer races because I went up to Canada to play golf and then ended up sticking around for a month helping out the grandparents. I got a bit of road and mountain riding in there that I guess I'll post about later. Now I'm back in MT and it's fire season so there is a ton of smoke around. Cross starts in about a month and then fall kind of turns into a whole new mtb season when we get some moisture on the trails. Right now I'm debating going to the TNR ride as the air quality is right above the "unhealty" line on the chart, but has been improving since this morning. Will probably go anyway and try not to pedal too hard.

Monday, May 29, 2017

Rocky Mountain Roubaix

I think the Rocky Mountain Roubaix is Montana's longest running bike race, and it was the first real road race I ever entered. Road racing has been in a bit of a decline around here, with more people opting to race mountain bikes and cyclocross instead. The wednesday series' are inexpensive, easy, and fun. Traveling to road races, on the other hand, tends not to be. You often spend the day suffering alone, and then half the racers have left the time the awards start. I'm starting to think that having free beer and a bbq or something is key to good racer turnout.

Anyway, I've done the roubaix 5 times now, but since it's about our only road race I have been stuck in category 4. I was offered an upgrade to cat 3, but haven't had a reason to buy a USAC license because most of our races, including the roubaix this year, don't require one. Like the Hell Ride, this was ran as a "gran fondo." So there was the choice of the A race of 70 miles or B race of 40 miles. Having always been in the "B" race as a 4/5, this was my chance to ride with the fast guys.

Last year it was pouring rain and miserable. The dirt sections were slick mud and you couldn't see where you were going. It ruined all the bearings and cables and housings on my caad 9 and that was the last time I ever rode it since the crack in the chainstay had been growing. This year the forecast looked decent- just cloudy with possible showers. So of course in the morning it was raining, but I felt optimistic. Then I got to frenchtown, and it was still raining, and looked like it was raining on the course. So, yeah, it rained again. And was cold.

Friday, May 26, 2017

2017 Montana Hell Ride

I suppose road racing season is over already, after speedwagon, the hell ride, and roubaix. I wanted to set up some sort of prizes for the people who did all three (there are only 7 of us), but so far that hasn't happened.

Last time I mentioned a possible new road bike, and, well, I have this:


Saturday, April 8, 2017

A new bike season

I guess it's been awhile since I posted anything on here so here is what I've been not doing lately. Winter was pretty long this year, and after riding and racing pretty much non-stop from mid-January through the end of November I was not all that motivated to work out and ride the trainer.

I did ride the trainer a few times, and I did walk and hike a few times, cross country skied, downhill skied, but it wasn't a whole lot. 2-3 hours was a big week for me. What I did do was drink plenty of beer and sit around.