Cyclocross - Sram apex in a 1*10 set up

So thinking about building out a new cross bike and was wondering about using the new sram apex in a 1*10 configuration with the 11*32 cassette in the rear . Does anyone see an issues with this ? What do people usually use on the front 39 or 42 when running a single ring?

That should work fine.

As far as the single front goes, here is some food for thought...

Assuming a 700x32c wheel and tire:
39x11 @ 100rpm = 28.5mph
40x11 @ 100rpm = 29.2mph
42x11 @ 100rpm = 30.7mph

Would you be able to get away with a short cage RD or need to go to a long cage with that configuration? I was thinking the same thing but didn't want to have to put a long cage RD on.

I'm running the 11-32 Apex cassette with Ultegra and works great. A short arm should be fine on a 1 X 10 set-up.

Michael

I'm running the 11-32 Apex cassette with Ultegra and works great. A short arm should be fine on a 1 X 10 set-up.

Michael

wait I thought you need the apex RD to work with the cassette?

wait I thought you need the apex RD to work with the cassette?

The SRAM RD and shifters need to be matched, but the cassettes have the same spacing as Shimano.

I've had issues with a short cage derailleur and a 32T cog before. The upper pulley didn't have enough space between it and the cog.

The SRAM RD and shifters need to be matched, but the cassettes have the same spacing as Shimano.

I've had issues with a short cage derailleur and a 32T cog before. The upper pulley didn't have enough space between it and the cog.

This can be a problem, The Ultegra is rated at a 27 max cog size, but there is tolerance built into the spec.

It's the combination of hanger design & derailleur that determines the fit. My Lynskey frame in combination with the 6600 Ultrgra works great. YMMV.

Use a long arm Shimano Deore SGS, it is rated for a 34 and will work for sure. Nothing wrong with using the Sram Apex Shifters/Deraillers/Cassettes either ;-).


Michael

What are you going to be using the bike for? Cross racing, singletrack, commuting, pseudo-road bike? The only use I can honestly see for a 1x10 with such a wide gear range is for a dedicated singletrack/mtb trail bike, in which case I'd rather just buy a mountain bike.

If you're using it as a pseudo-road bike, you'll hate the 42x11 max gear. You won't be able to keep up with roadie friends once the grade starts to slope downhill. This is a criticism of the 1x10 setup, not the gear range.

If you're using it for cross racing, at least in my experience (Central TX), you'll have very little use for the low gears. I'm of the mindset that anything you can't ride in 39x23 is a run-up. My opinion may be biased, because that's the low gear I'm packing on my cross bike, and also because I'm a roadie with crappy MTB skills. It's easier, and more importantly, faster, to throw the bike over your shoulder and run than it is to try to recover once you try to ride something steep and fail halfway up.

For what it's worth, my cross bike does double duty as a commuter and a cross racer. I occasionally hit some tamer singletrack, but not enough to pick my gear range for that application. Once in a blue moon, I ride it as a pseudo-road bike, but most of its road use is commuting. Still, I'm running road bike gearing on it: a 53/39 up front with an 11-23 or 12-23 on the back, with no particular rhyme or reason to the choice of cassette (whatever's on the wheels I happen to be using).

I have never had the occasion to use the 53t ring off-road, but it's nice on the commute, and it helps keep the chain on. I have yet to race it on a pavement-heavy course, however; it's entirely possible that I'll run into a situation where 39x11 is not enough gear. Most of the racing around here keeps me in the 39x23-17 range, though.

I'm of the mindset that anything you can't ride in 39x23 is a run-up. My opinion may be biased, because that's the low gear I'm packing on my cross bike, and also because I'm a roadie with crappy MTB skills. It's easier, and more importantly, faster, to throw the bike over your shoulder and run than it is to try to recover once you try to ride something steep and fail halfway up.

Can we talk about this? I hear and read this all the time, and I'm starting to think it's wrong.

Let me throw out some numbers. At a cadence of 40 rpm (seriously mashing), you'd get the following speeds with the respective gear ratios:

39x23 => 5.5 mph
39x25 => 5.0 mph
39x27 => 4.7 mph
36x23 => 5.1 mph
36x25 => 4.7 mph
36x27 => 4.3 mph

At 60 rpm (still mashing), you get these speeds:

39x23 => 8.2 mph
39x25 => 7.6 mph
39x27 => 7.0 mph
36x23 => 7.6 mph
36x25 => 7.0 mph
36x27 => 6.5 mph

Now the question is, how fast are you going to run up that hill? If it's a short hill, and you can bound up it, then probably you want to do that, but for longer hills, I don't think so. I think we'd all agree that it's all about efficiency. In most circumstances, riding is more efficient than running. So, it seems to me that unless you aren't going to be able to ride the hill, you should ride it, regardless of gearing.

So it seems to me that the only argument that holds water is to say, "It's better/faster/more efficient to run a hill than to try to ride it and fail" (which is what you actually said), but this is distinctly different from the typical argument I hear that "If I can't ride it in X gear, then it's better/faster/more efficient to run it."

Given the above reasoning, I think it makes sense to give yourself the lowest gearing you might need. There are a few races around here with substantial hills, and I've decided to bring a 50-39-30 triple with a 12-27 cassette to those races. At the first of these a couple of weeks ago, I used the 30-27 gear and was riding past people who were "running" up the hill.

I'm not trying to be beligerent here. I really would like to hear the logic from the other side.

Given the above reasoning, I think it makes sense to give yourself the lowest gearing you might need. There are a few races around here with substantial hills, and I've decided to bring a 50-39-30 triple with a 12-27 cassette to those races. At the first of these a couple of weeks ago, I used the 30-27 gear and was riding past people who were "running" up the hill.

I'm not trying to be beligerent here. I really would like to hear the logic from the other side.

That's why I qualified my post with my location - those types of hills just don't exist on CX courses around here. I've never traveled further than San Antonio for cyclocross, though, so my experience is admittedly very limited, geographically.

That's why I qualified my post with my location - those types of hills just don't exist on CX courses around here. I've never traveled further than San Antonio for cyclocross, though, so my experience is admittedly very limited, geographically.

I thought Austin was the part of Texas that wasn't flat. I guess that's relative. :)

I run 11-32 with a 44t ring.

-Z