CX gearing options

[Gfi3]

I apologize if there is already a thread on this subject here, but I couldn't find one.

Just bought a cheapo cx bike (KHS CX 100) to give racing a go this season. At my first race last week I noticed a number of riders with a single ring up front. My current setup came with compact cranks 50/34 and an 11-32 in the rear. Seems like an ideal setup to swap to 1 x 10.

I didn't find myself using either high or low extreme of my gearing and I'm drawn to the simplicity of the 1x system.

Anyone have experience with this or a good recommendation for front chainring size? Or overall gearing in general? What do my fellow cx racers on here run?

Thanks!

[alioup]

46/36 is the go-to for most people.

[spartanKid]

42 w 11-28 is a pretty common 1x9/10/11 set up. Some pros will run 44T front single rings depending on the course.

46-36 is the most common double set up on new bikes. 46-38 is what most pros run. 44-34 is out there as well.

If you've got 11-32 in the back, I'd look at doing a 42 or 44 single ring, or a 46-36/38 set up, depending on if you're going to be using the bike ONLY for racing or for other stuff as well.

I run 44-34 with an 11-28, the goal being to stay on the 44 as long as possible, as dropping to the 34 during races is slooooow, but I like the 44-34 for taking the bike on trails and gravel roads and things.

[vav]

46-34 and 11-32 on my Zanc CX. Perfect for most of my riding. Buy a 46t 110 bcd chainring and call it a day.

[Gfi3]

Thanks. I don't intend on using it for much else besides racing. I'm leaning towards going with a 42 up front and leaving the 11-32

[RacerJRP]

Personally for a single ring setup I am a fan of the 40t up front. run it with 11-28 or 11-32 depending on the course.

[christian]

I run 39t w 12-25 for racing. I'm slow though.

[Hepmike]

Keep in mind if you go with a single ring up front, you're going to need a K-Edge or Paul C chain catching system, or you're just going lose your chain. The K-edge stuff worked great for me, the Paul C is very sensitive to get setup properly.

[Dromen]

I like that the forum allows my obvious answered and semi stupid questions....

So i just remove the RD, inboard chainring and add the chain catcher and im officially a 1X9/10/11? Gotta be something else.....

[11.4]

I'm not sure why 36/46 is the industry OEM standard. Unless your cross is dead flat or has some paved stretches, the 46 is just a chain guard. I think Richard Sachs still does like a 34-42 and he's damned fast. Most of the riders I know that can win a race in the US, short of the few elites, can do just fine on a single-speed 40-42 or a 34-42 or at most 34-44.

If you want to do a single front chainring, then really think about setting up your bike completely differently. Do a rear derailleur with a clutch like the new XTR (which works with Dura Ace) so you maintain chain tension, don't use too much chain (most people take off a 46 and forget they need to shorten the chain), and use a ring with high teeth and mixed widths so the ring simply stays in place. With that, it has to get pretty gnarly for you still to need a chain guard. I've seen a few very fast riders using a Saint rear derailleur and riding chopped flat bars on the front -- you can use basic XTR or XT cockpit hardware and with the bars narrow, you can squeeze through all kinds of holes in the pack. It sounds odd at first but it's actually pretty cool and it's fast. You can use a Saint crankset too if you can work out the clearances and Q-factor, but it has great gearing for cross. In short, it's time to re-think cross. Unless you are collecting UCI points, be open to different ideas and look at everything that the MTB side of the world has brought to the market. Shimano has now finally made them compatible with road, and it opens a lot of opportunities.

[11.4]

I like that the forum allows my obvious answered and semi stupid questions....

So i just remove the RD, inboard chainring and add the chain catcher and im officially a 1X9/10/11? Gotta be something else.....

You mean remove the FD? Yes.

And as I said in the post just above, shorten your chain. Consider getting a clutched rear derailleur. Get a chainring made for single-ring. Probably you will want a wider range on your cassette -- this is where an 11-speed 11-32 Ultegra or an 11-speed 11-36 or whatever from the mountain stuff is useful.

[Dromen]

yea FD.

I was thinking, WiFLi RD w/ 46X11/32, standard chain with Chain catcher. Wanna use components i have laying around to try it. OR is the WiFLi with SS chain and no chain catcher a better option. Bet your going to say, with the WiFLI you better use the SS chain and catcher.

[thirdgenbird]

Keep in mind if you go with a single ring up front, you're going to need a K-Edge or Paul C chain catching system, or you're just going lose your chain. The K-edge stuff worked great for me, the Paul C is very sensitive to get setup properly.

Did they change the Paul keepers? I've heard they were troublesome but I just installed one on a 1x10 mountain bike and had no problems setting it up without rub in any of the gears. Easier than setting up any front derailleur.

[Hepmike]

Did they change the Paul keepers? I've heard they were troublesome but I just installed one on a 1x10 mountain bike and had no problems setting it up without rub in any of the gears. Easier than setting up any front derailleur.

Not that I'm aware of. The issue is it can look like it is correctly installed/spaced, until you hit just the right kind bump and it will come off and there's no way you're getting it back on without using a wrench. Ruined 2-3 CX races for me. I switched to K-Edge and so far so good .

[bcroslin]

What options are there for running a different (smaller) big ring on Shimano CX-70 cranks? I've got a a 46/34 but definitely need something smaller to replace the 46.

[Gummee]

What options are there for running a different (smaller) big ring on Shimano CX-70 cranks? I've got a a 46/34 but definitely need something smaller to replace the 46.

AFAIK the smallest rings you can run are 34/X. X being what you want to run as a big ring. I ran 34/44 the last 2 years. I went Ultegra this year and the only way to get that crank was 36/46

So far, in some practice CX racing, its going OK

M

[bcroslin]

AFAIK the smallest rings you can run are 34/X. X being what you want to run as a big ring. I ran 34/44 the last 2 years. I went Ultegra this year and the only way to get that crank was 36/46

So far, in some practice CX racing, its going OK

M

The 34 is fine but I'd like to replace the 46 with something smaller like a 44 or maybe even a 42. There's a ton of options for sram but I'm not seeing much for shimano.

[brando]

My first cx bike had 44-34 and 25-11. Really was happy with that. If I still raced geared I'd do it again, but having a blast in single speed.

[Gummee]

The 34 is fine but I'd like to replace the 46 with something smaller like a 44 or maybe even a 42. There's a ton of options for sram but I'm not seeing much for shimano.

IIRC KFC races a 34/42 combo, but I'm too lazy to hit the googles to confirm.

Lots of folks race 34/44.

If you're on a CX70 crank*, you can run anything but they come 36/46. Smallest 6800 comes is 36/46. 9k doesn't even go that small.

...but it also depends on what category your're racing. If you're in the 'killer b-s' like I am you may want to run that 46 'cause most of the front-runners will be.

M

*or other 110bcd crankset

[Gfi3]

Keep in mind if you go with a single ring up front, you're going to need a K-Edge or Paul C chain catching system, or you're just going lose your chain. The K-edge stuff worked great for me, the Paul C is very sensitive to get setup properly.

Thanks for the suggestion - the ones I see look like they mount to FD? Wouldn't I be removing that though by going to a 1X setup? Do they make another version?

Also if I just use my existing cranks and mount a high tooth 40T ring is there any issues with cross chaining when going to my large 32T on the cassette in the back?

[sandyrs]

What options are there for running a different (smaller) big ring on Shimano CX-70 cranks? I've got a a 46/34 but definitely need something smaller to replace the 46.

110 bcd, so chainrings are widely available.

For example, TA Zephyr (http://www.specialites-ta.com/gb/plateau-zephyr.html) rings are available down to 40 teeth for the outer ring.

[thirdgenbird]

Thanks for the suggestion - the ones I see look like they mount to FD? Wouldn't I be removing that though by going to a 1X setup? Do they make another version?

Also if I just use my existing cranks and mount a high tooth 40T ring is there any issues with cross chaining when going to my large 32T on the cassette in the back?

K edge makes a single ring guide that clamps around the seat tube. I would team it up with a bash guard style guide on the outside.

Run the single ring on the inside of your crank arm and you shouldn't have any issue with the 32t.

[oldpotatoe]

I apologize if there is already a thread on this subject here, but I couldn't find one.

Just bought a cheapo cx bike (KHS CX 100) to give racing a go this season. At my first race last week I noticed a number of riders with a single ring up front. My current setup came with compact cranks 50/34 and an 11-32 in the rear. Seems like an ideal setup to swap to 1 x 10.

I didn't find myself using either high or low extreme of my gearing and I'm drawn to the simplicity of the 1x system.

Anyone have experience with this or a good recommendation for front chainring size? Or overall gearing in general? What do my fellow cx racers on here run?

Thanks!

Variety of courses, yes? Not just the one. Gearing is personal..what one uses may not work for another. I'd say a smaller big ring, 'maybe' a larger small ring and perhaps a cogset in the rear that is closer spaced..like a 12-27 or so but it depends on you and the course.

If ya do go 1x , ya still need to do something to keep the chain on the single ring.

[oldpotatoe]

I like that the forum allows my obvious answered and semi stupid questions....

So i just remove the RD, inboard chainring and add the chain catcher and im officially a 1X9/10/11? Gotta be something else.....

I'd probably put the single ring on the inside for chainline.

[Gfi3]

It looks like SRAM had already taken the lead on this with their CX.1 line. CX specific single ring cranksets compatible with 10 and 11 spd setups. Now I just have to decide which size chainring to go with. Thanks everyone for all the input and help. Making this a lot easier for me.

[chiasticon]

i can't lend experienced advice here as this year will be my first attempt at cx and i've not raced yet. but conversations with friends have told me that a lot of them will run 36/46 in the front and not use the big dog much in races, except for rare fast, dry and/or downhill sections. but they keep it on because they use their bike for some road riding too during cx season. my experience in cx practice so far has lead me to believe i'll likely be in this same camp.

just throwing that out there for all those that are comparing themselves to what gearing pros are using. they likely don't use the same bike for 60 mile training rides on the road during cx season.

[atrexler]

I run a 1x9 on my cross bike. 39t on the front and I'm rarely thinking "I need a heavier gear to mash on". Gearing is partly personal preference though, so if you like to push something heavier then a 42 or so might be a good choice. Consider the type of courses you'll be on and your riding style. Grassy flat and fast stuff means you might want a heavier gear...might.

I also have a Paul's keeper up front-- a bit tricky but I didn't find it overly hard to set up properly. Then again I only run a 9 speed cassette.

[bcroslin]

110 bcd, so chainrings are widely available.

For example, TA Zephyr (http://www.specialites-ta.com/gb/plateau-zephyr.html) rings are available down to 40 teeth for the outer ring.

So any 5 hole 110 outer chain ring should work. Sweet.

[Gummee]

i can't lend experienced advice here as this year will be my first attempt at cx and i've not raced yet. but conversations with friends have told me that a lot of them will run 36/46 in the front and not use the big dog much in races, except for rare fast, dry and/or downhill sections. but they keep it on because they use their bike for some road riding too during cx season. my experience in cx practice so far has lead me to believe i'll likely be in this same camp.

just throwing that out there for all those that are comparing themselves to what gearing pros are using. they likely don't use the same bike for 60 mile training rides on the road during cx season.After CX season, I'll typically stick some 34/50 rings on my bikes with bottle bosses and ride em on dirt roads too. I start training for things like the Devil's Backbone ride(s) and Hilly Billy Roubaix over in West-by-doG soon after CX season ends.

Rode the Altamira CX in the Hilly Billy last time. The 36/46 was OK, but a 34 inner would've been better. Ditto with a 30t cassette. ...but I didn't have time/$ for either last time. :cry

M

[xjoex]

I'd say whatever feels good! I use a 32 x 36 when racing, you can ride hills others run!
https://lh6.googleusercontent.com/-fJ4sHWd_pqU/VAYcBsO96_I/AAAAAAAAStQ/_6cEoS_lnk8/s800/tumblr_n5fm8t9LtT1rqzd9vo1_1280.jpg

-Joe

[ChrisG]

Variety of courses, yes? Not just the one. Gearing is personal..what one uses may not work for another. I'd say a smaller big ring, 'maybe' a larger small ring and perhaps a cogset in the rear that is closer spaced..like a 12-27 or so but it depends on you and the course.
As others have said, there are several personal variables to consider, but if the rig is primarily for racing, I think the rear cog spacing matters. Anything bigger than 12-27 presents some pretty big jumps between cogs. FWIW, I run 12-25 on my race wheels.

For my needs, if I'm pedaling a 34x32 up a hill in a cross race, I'm probably better off running it anyway.

[AnthonyC]

Does anyone have any experience with gearing for Southern California CX racing in particular?

I'm used to running a 44/38 with a 12-25 in Mid-Atlantic races on the east coast, which served me pretty well in the crazy range of conditions we face out there. (Dry, mud, snow, etc.) However, now that I've moved to CA I'm not sure what to use.

Should I adjust my gearing here in SoCal in any way? Should I use a steeper big ring like a 46T, given that it's going to be high and dry? A wider range cassette? Any tips appreciated!

[Gfi3]

K edge makes a single ring guide that clamps around the seat tube. I would team it up with a bash guard style guide on the outside.



Run the single ring on the inside of your crank arm and you shouldn't have any issue with the 32t.


I'm having trouble finding a bash guard with 5 bolt compatibility that is in the 40T size range. Are there any other options besides running the single ring on the inside? Is that what most people do? And the chain catcher of course.

[thirdgenbird]

I'm having trouble finding a bash guard with 5 bolt compatibility that is in the 40T size range. Are there any other options besides running the single ring on the inside? Is that what most people do? And the chain catcher of course.

Have you taken a look here?
http://www.bbgbashguard.com/Cyclocross.html

He should have one that will suit your need at a very reasonable price.

[Gfi3]

Have you taken a look here?

http://www.bbgbashguard.com/Cyclocross.html



He should have one that will suit your need at a very reasonable price.


Wow thanks. Perfect! Would you recommend going one sizer larger than my chainring with the BG?

[christian]

As a -bash-guard they're sized right for the ring they state. i.e. I have a 32t ring on my mtb and a 32-sized BBG bash guard. The guard is big enough to protect the ring and chain.

If using them for chain retention purposes, I don't know. The only methods of 1x chain retention I trust are narrow-wide rings with a clutch derailleur or a front derailleur locked in position (or not) or an ISCG chai guide. For a cx bike, the two first are options. I have heard too many stories about other options.