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View Full Version : CX single ring on a double crankset - advice


FastforaSlowGuy
10-09-2014, 09:46 AM
I'm putting together a CX build and am interested in turning my double crankset into a single ring setup. Do I install the ring on the outside (as Praxis shows), or on the inside with a bashguard on the outside (as I've seen elsewhere?

bicycletricycle
10-09-2014, 09:48 AM
inside with bash on outside should yield better chainline unless you are always super truckin in the 11

thirdgenbird
10-09-2014, 09:49 AM
I've done inside with a bash guard. Praxis probably doesn't want to hide their product.

Bruce K
10-09-2014, 09:56 AM
As said above

Inside with a bash guard or chain keeper ring on the outside yields a better chain line

Keeper on the inside or over the top to prevent drops

BK

Kirk Pacenti
10-09-2014, 09:58 AM
Inside w/ guard on the outside, plus a keeper if you're not running a thick thin style ring w/ a clutch RD.

Cheers,
KP

FastforaSlowGuy
10-09-2014, 09:59 AM
This makes the most sense to me. The Praxis thing confused me. It seems a lot tougher to get the chain deflector positioned properly if the chain is on the outside, and then you're loosing the drop protection you'd get from the guard.

After yesterday's news that I'll be working through the last road race of the season (on Columbus Day), I've decided to drown my sorrows in CX. I'm sure I'll come very close to killing myself, but a little fun and competition is what's needed right now. I spent last night dialing in the fit, and I think I'll make the 1x leap to simplify things.

robin3mj
10-09-2014, 10:02 AM
What kind of r/d are you using?
If conventional, I would put the ring on the inside, and get a bashguard and dog-fang. BBG makes all BCD/sizes/colors for nice and cheap.

If using a clutch r/d, you can put the narrow-wide ring on the outside and fuhggedaboutit.

old fat man
10-09-2014, 10:05 AM
This makes the most sense to me. The Praxis thing confused me. It seems a lot tougher to get the chain deflector positioned properly if the chain is on the outside, and then you're loosing the drop protection you'd get from the guard.

After yesterday's news that I'll be working through the last road race of the season (on Columbus Day), I've decided to drown my sorrows in CX. I'm sure I'll come very close to killing myself, but a little fun and competition is what's needed right now. I spent last night dialing in the fit, and I think I'll make the 1x leap to simplify things.

If you're cutting corners on your 1x setup, you will not simplify things. I've raced cx all over New England with a 2x10 drivetrain for nearly a decade and never had issues nor felt that it was complicating things. Plenty of 1x setups again these days, but you need to do the following at a minimum ATMA

- use a wide/narrow front ring (best thing to do)
- use a clutch type derailleur if possible (X9 or the CX specific ones)
- keep your chain length to a minimum
- if not using a clutch type derailleur, i'd recommend a chain guide of some sort up front for the added security. keep in mind though, if your chain gets stuck with the guide, it'll be even worse than not having a guide

sandyrs
10-09-2014, 10:34 AM
Racing this weekend?

FastforaSlowGuy
10-09-2014, 10:38 AM
Racing this weekend?

A buddy is trying to talk me into doing Lancaster on Saturday. Everything is full except the SS race. I haven't made up my mind on that yet, but I spent $30 to register so I could mull it over in peace. I think I'll get up Saturday morning, see whether I can figure out the dismount/remount thing, and then decide.

Otherwise, I'm definitely going to do a race in Keene, NH next weekend. Looks more technical, so maybe tougher for a first-timer.

FastforaSlowGuy
10-09-2014, 04:55 PM
A related stupid question: What do the tooth-size references mean on chainguards (size of the chainring it's replacing, or the max size of the chainring it can guard?), and how closely do I need to match it to the chainring I'm using?

sandyrs
10-09-2014, 05:06 PM
A buddy is trying to talk me into doing Lancaster on Saturday. Everything is full except the SS race. I haven't made up my mind on that yet, but I spent $30 to register so I could mull it over in peace. I think I'll get up Saturday morning, see whether I can figure out the dismount/remount thing, and then decide.

Otherwise, I'm definitely going to do a race in Keene, NH next weekend. Looks more technical, so maybe tougher for a first-timer.

Lancaster is on Sunday!!

eBAUMANN
10-09-2014, 05:21 PM
if you don't have a clutch, adhere to the "WWBBD?" (http://velonews.competitor.com/2014/10/news/cyclocross/pro-bike-gallery-ben-berdens-raleigh-rxc-pro-2_348856) motto.

if you do have a clutch, a wide narrow ring works on either the inside or outside of the spider, though will probably yield a better chain line on the inside, as you will probably use the top end of your cassette more than the bottom in a cx race.

i think a bash guard is unnecessary for clutched wide-narrow drivetrains, and even for non-clutched - see ben's setup (http://velonews.competitor.com/2014/10/news/cyclocross/pro-bike-gallery-ben-berdens-raleigh-rxc-pro-2_348856) for a great example.

bottom line, these days, there is no reason to NOT have a wide narrow ring, they really do make a huge difference.

zacstanley
10-09-2014, 05:24 PM
I'm using a plain ol' Rival RD with no-clutch and a 44t wolf tooth on the outside. Nary a single dropped chain when using wolf tooth's method for chain length.

Zac

eBAUMANN
10-09-2014, 05:35 PM
I'm using a plain ol' Rival RD with no-clutch and a 44t wolf tooth on the outside. Nary a single dropped chain when using wolf tooth's method for chain length.

Zac

fine for general riding when a dropped chain only means a stop and some dirty fingers - in a race however, a dropped chain without a fd to shift it back on is a pretty huge set-back. not to mention if mud is involved...that chain won't be on there for very long.

a clutch/catcher-less setup is possible, and it will work almost all of the time, but its that one time it drops and ruins your race that will have you singing a different tune ;)

pavel
10-09-2014, 05:37 PM
get a sram x-sync ring. They are machined in such a way that the teeth are almost cantilevered over the edge which offsets them (the other narrow wide rings dont do this.) this way you can run it in either position and probably a lot less need for a bash guard.

zacstanley
10-10-2014, 12:10 AM
fine for general riding when a dropped chain only means a stop and some dirty fingers - in a race however, a dropped chain without a fd to shift it back on is a pretty huge set-back. not to mention if mud is involved...that chain won't be on there for very long.

a clutch/catcher-less setup is possible, and it will work almost all of the time, but its that one time it drops and ruins your race that will have you singing a different tune ;)

3 races this season in bumpy, dry northern california and no problems. I ride fire roads with thaissetup all the time and haven't dropped a chain yet.

Works for me.

Zac