Niloc

Hey all, I did my first CX race ever this past Sunday at Woodland Park in Seattle and loved it! I raced in the beginner men's category (Cat 5 elsewhere I believe) and didn't finish too bad for my first outing - in the top quarter of a large field.

I'm already planning on doing a couple more races before the season is over, and I have some repairs to do to my gear that I'm hoping to get opinions on.

I run a flat bar (well a Origin8 "Space Bar") with mountain bike style brakes and thumb shifters. I found this set up worked fine, and I plan to stick with it. I ride drops on my road bike and I don't think I would have ever used them on this course. Anyways right before the race, I went to adjust the position of my left shifter on the bar and discovered the clamping bolt hole was stripped! The shifter is an old XT thumbie from the late 80s (I love this style of shifter) but I guess it's finally worn out. So I left the shifter on, pushing it onto the curve in the bars which kinda held it in place, and a friendly team tech gave me some zip ties to space it away from my brake lever. I knew I wouldn't be able to use it to shift but if I was careful I could at least trim the derailleur if I needed to. The tech said I wouldn't get out of my small ring anyways and he was right. I'm running a Ritchey WCS 46/36 chainset and there wasn't anywhere on the course I would have liked to be able to shift onto the 46. My cassette is a 9 speed 12-25 and I didn't get into the small cog on the 36, in fact I'm not sure I even got into the second smallest cog.

So, I've got to do something with my drivetrain and this experience is definitely getting me thinking why even fix the left shifter, should I just run a single ring up front? The Woodland Park course is hilly and twisty and I suppose there are other courses that will have longer and firmer straightaways so maybe it's a bit of horses for courses. The only paved section on the Woodland Park course was on a slight uphill grade. I'm in the NW though and we have hills and lots of rain (mud) so my understanding is that our courses are slower than average. If true I guess that would tend to favor the single ring set up b/c you're not going to need to get in that big ring and grind up to high speed. Anybody care to comment on the courses around here I'm all ears.

I would like to use this bike for other things than CX, but it's not my only bike so it's not like I need it to be able to do everything all the time. Keeping the bike more flexible for things other than cross racing is one of the main reasons I read about for people keeping their compact doubles.

- So if you don't have to worry about that issue, would most of you run a dedicated single ring race bike?

Regarding a single ring set up, I could change up the rings on my Ritchey WCS compact but I actually have a old Dura Ace road double (53/39) laying around that I could use as a single ring crank by swapping the 53 for a bash guard and maybe replacing the 39 (it's worn) with a non-shifting type ring in the 38 to 42 range. That way I could just swap off the cranks when I want to go back to a double after cross season for commuting, trail riding etc. Swapping cranks might be easier than swapping two chainrings. BTW it's an Octalink BB which I don't think wears out like a square taper for changes, does that sound right? I'm thinking the Dura Ace might be a bit heavier but would be stiffer b/c the inner ring lower limit is 38T (right?) rather than the 34T of the compact. So I'd be swapping the crank twice a year.

So questions regarding the single ring set up:

- Which crank, the WCS compact or the Dura Ace double?
- Which chainring? The 36T was plenty on Sunday, but I'm thinking if I go single I'll bump it up a bit. I've read that 42 is common, but that seems a little high to me.
- What cassette? My cassette is at least 10 years old and pretty worn so I don't mind replacing it. I did get some skipping in the rear end on this race, hoping a new cassette with taller teeth will resist clogging longer. Anyways it's a 12-25, thinking if I go single with a larger than 36T chainring, I'll get a 12-27 cassette. Or maybe even a 13-? I want to keep my Ultegra RD so I don't want to go larger than 28T plus I don't think that's necessary for cross.
- The chainline won't be centered, is that a problem? My BB is Octalink 109 for a double, so the inner chainring will be skewed a bit towards the inside of the cassette. I didn't find this problem Sunday, but like I said I never even used the smallest cogs. I think having the chainline skewed towards the inside is better than having it skewed towards the outside. I.e. inside ring to small cog is easier for the chain and derailleur to handle than outside ring to big cog. I don't want to have to swap out the BB if I can avoid it, Octalink V1 BBs are hard to find and I'd rather not have to swap the BB in and out as well as the cranks.

I already have a third eye chain watcher on the seat post for the inside, I'll need a bash ring for the outside, tempted to just get an old ring from the used place slightly bigger than the one I run and grind down the teeth, has anybody done that? If not recommend me a bash ring.

Thanks all

Andy_K 

I thought all you Seattle guys rode singlespeeds.

I've been racing on 1x10 for a few years now. I used 36x13-25 the first year, and I spun out on the 36x13 combo exactly once in about 15 races. The problem I have is that I tend to find my way into the lowest gear I have, so bumping the front ring up to 38 forced me to be faster. I use 38x12-25 now, except on a couple of course with nasty hills where I break out the 12-30 cassette.

Whatever crankset you use (I'm not sure it matters much) you'll want some kind of chain retention system. This can be as simple as a front derailleur fixed in place. I use an N-Gear Jump Stop and a BBG bashguard, though frankly I'm not sure that's as effective as an old derailleur would be. I've only had a problem with it twice, and both times were setup issues. BBG bashguards are nice and reasonably light.

flargle

CX gear for suckers:
1) File treads
2) Tubeless
3) Single ring

The beauty of double-ring setup is, some courses are small ring courses, some are big ring courses, and some are mixed, and you have all that covered with a 36/46 (or make it even tighter, 36/44) setup.

The myth is that single ring is simpler. It's not.

When the season's over, you plop on a 50/38 set of rings and have awesomer road setup.

scrub

On the occasion I race a geared bike I have been known to ride a 42 front with 12-26 (8 speed shimergo), it did me fine last season in Seattle. You'd probably be fine with that 39, I too use a BBG bashguard and either a deda dog fang or an N Gear Jump stop.

I have friends running 1x10 with wolf tooth chainrings that are quite pleased.

TLDR 1x is great.

Niloc

Thanks for feedback guys. Flargle you're definitely giving me second thoughts. It does seem like single speed isn't as simple as it sounds. In some ways it seems even more likely you'll drop a chain which is counter-intuitive to me but IIWII. The weight savings seems minimal and at I'm not a gram counter (which would be silly considering the rest of my gear and my competition level)

A double certainly gives you a wider gear range, with less cross chaining, but in my area, at my level, if I'm not going to really ever need the big ring then I do wonder about trying out the single ring.

Another issue specific to me is that I'm running a Ritchey compact double which has a not standard crank spider pattern, with a "hidden" fifth arm and the chain drop pin in a non-typical location. Ritchey doesn't make them anymore so replacements are hard to find. So I won't likely be able to go to a 44 or 42T ring. Unless I just forget about the chain drop pin issue.

Andy_K 

You'll drop the chain a lot less with a singlespeed setup, but 1xN is generally worse than 2xN in that regard.

flargle

I would agree with this statement in general but not universally. I have a very clever friend who runs a 1x10 with a narrow/wide chainring and clutch derailleur and so far has had zero problems. He also runs tubeless without issue. (So far. I believe every CX tubeless setup is a failure waiting to happen.)

nacler22

I've run a 1x10 with zero drops/issues in 30+ races. This weekend I garbled an off camber, and managed to get the chain stuck between the K-Edge and chainring: race over. I'll take those odds every time for the simplicity of a single ring.

Also, I've never spun out my 39x11.

flargle

I don't get the "simplicity" if you need an inner guard, an outer guard, and a dropped chain turns into a DNF.

Front ders have always been cheap, and you can get left shifters for cheap on eBay because of all the guys looking for simplicity.

Niloc

Flargle I think you've convinced me to stick with my double chainring, now please jump over to my other thread about seven speed rear ends and let me know what you think. I think it may be simpler :-)

nacler22

I think that my simple is different than your simple. My inner and outer guards were simple to set, then forget. The most important "simple" to me, is the lack of front shifting. I am a lazy overachiever, and less is more when it comes to me and shifting. As far as my DNF, I'm not making a case for, or against, single-rings being more,or less dependable. I just like my odds as it relates to my races.

Sorry it took me so long to respond. I had to go to my daughter's fencing class(I **** you not), and then went for a training ride on my 1x11 MTB.

Niloc

Hmmm ok I'm flip flopping. No I'm not going to a fixed / singlespeed hub. ;-) But I am wondering about trying single ring again. Talked with friendly tech at bikeshop who also races 'cross and he has been helpful. I think I could try single ring without too much trouble. That way I wouldn't have to fix my left shifter either! I'm considering building a 7 speed rear wheel and then I might do 2x7 but that's gonna take a while.

So I'd probably use my Dura Ace double with I'm thinking a 40T and 12-27 8-speed in the back. Just need a bash ring to replace the outer. One question I have is do I need to worry about centering the chainline? My tech buddy says no he just runs the single ring on the inner position without problems; he says he's more on the bigger cogs on the cassette anyways which does make sense. Do you single ringers do the same, or try to center your chainline?

It would be a $ PITA for me to try the replace my V1 octalink BB with one with a longer spindle, but can you shift it over a bit with spacers?

nacler22

I just run my ring on the inner, and it works fine.

linus

IME, non-2bless tires will fail eventually if you set them up 2bless, however actual 2bless tires will not.