oharescrubs

so at my LBS, dude insists that for cyclocross i should only have 1 chainring up front... and really didnt offer any other reasoning other than, "thats what id do." uh... anyone have any knowledge or experience to drop on this?....

cyclintom

It depends on what you intend to do.

If you're going to race local races on tight closed courses then perhaps a single ring will work OK. The idea ORIGINALLY was that you'd not have the extra shifter and front derailleur. The problem with this idea was that the chain would jump off the ring frequently enough to be a problem and so you'd use the small ring of the double and place a plate on the big ring side and a chain watcher on the inside and those things ended up weighing as much or more than a front derailleur and extra shifter.

If you intend to RIDE the bike on multiple surfaces - that is use a cross bike as a cross BIKE and not a racer, then a triple is a good idea with MTB gearing as well.

Concerning tires while we're at it:

Narrow 28 mm (Vittoria Tigrecross I believe) or 30 mm tires with widely spaced knobs roll almost as good as road tires on hard surfaces. They work OK on hard packed trails as well. They SUCK for soft surfaces and mud.

Wider tires with more tightly packed knobs pack up with mud easily and also tend to wander around when you're on hard surfaces. But they DO have nice traction most of the time when your wheels are stuck immobile with mud.

Shifters? Everyone is used to using STI or Ergo now and it's probably a good idea if you're racing. But if you're doing only a small amount of racing and using your bike offroad there's certainly nothing wrong with barend shifters and they're more reliable and cheaper. I wrap the shift cables completely under the tape just like Ergo and the only problem is that you have to buy a Tandem shift cable for the rear derailleur because of the extra run.

On thing that irks me is that they aren't making the 14-30 9-speed setup. With a 50-34-24 that would be a very nice gear for general cross riding.

oharescrubs

dude, thank you very much... im pretty stoked to keep getting into this... to close the gaps of my sorta open ended question... i am planning on racing, wherever i can after i do some training (im a courier, so i get the excersize, but thats not really the same deal)... anyone in the dc area race? or know of any good resources? im a noob but want to get dirty building this thing up, and on the course.

RKR

If you're racing, any gear smaller than a 38 and a 25 is a waste because you can run faster than that.

Single ring set ups are lighter.

Chain watcher: 10g vs 80g record front derailleur
Shimano 600 Brake lever: 130g vs 160g record shifter/brake lever
Salsa Crossing Gaurd chain ring gaurd: 65g vs 71g Specities TA 46 tooth chain ring
Front Deraileur cable: 0g vs 60g

They are more expensive though, most chain ring gaurds cost upwards of $50 and most places won't sell you just a right hand shifter/brake lever.

Even without the chain ring gaurd the chain shouldn't fall of any more often than with a double as long as the chain is the proper legnth.

They are lighter and, because you're not shifting, there is less of a chance of droping the chain. That being said, I race a double (46/38) with a 3rd eye chain watcher.

jpearl

If you're looking to stay inside the District, there are some places you can get some 'cross practice. The most obvious is the unpaved, but hard and flat C&O canal. It's a great place to work on flat out speed and endurance. Rock Creek Park, nicely trashed from the tropical deluge of last week, allows some spots of slightly technical dirt riding, as well as on the section alongside the Potomac in front of the Kennedy Center. There are also a few dirt sections on the Capital Mall. If you really wanna hurt, turn laps on the short, steep cobbled hill just across from the Key Bridge in Georgetown, just a few doors down the hill from the bike shops. Be careful turning onto the climb, because it is a one-way street, and you will be going the opposite direction. Otherwise, it's a climb right out of a Spring Classic.

cyclintom

RKR: All of that trouble looking at the weight adds up to just a couple of ounces. Apparently you do realize that since you run the double yourself.

Weight weenie stuff isn't very effective for either your time or the reliability of your cross bike. After you've had a super light seatpost or bar snap off your entire outlook on "light" changes.

stric

Perhaps your LBS dude is right. Yesterday during my CX ride I didn't use my large chainring at all. I was in the smaller 39-tooth ring all the time. I run a 10 speed campy drivetrain so the range of gears was very wide and it helped a lot. Even on the road small ring-smallest cog combination offered a very good speed.

RKR

cyclintom: You said:
"...those things ended up weighing as much or more than a front derailleur and extra shifter."

And it’s not true.

I personally don't like single ring setups. But it isn’t right to convince someone against using a single ring setup by telling them something that isn't true.

jfmckenna

I raced a single ring set up for a few years. I ran a 42T ring with a 12x27 9 speed cassette. I switched to a double 38x50 last year with a 13x26 8 speed campy cassette and bar con shifters. The main reason why I switched is because I also ride this bike on the road for winter training and the big ring is really nice to have on the road. There was one race I did last year that actually included a running track in it where I used the big ring but other then that it's almost all small ring. A triple is definitely not a good idea in cross racing. Like some one mentioned if you have to go any lower then a 42x27 then you can run faster.

The nice thing about the single ring is that it's a pretty simple set up. I used a derailleur and pushed it down real low to keep the chain on and I never lost a chain. You do get a little weight savings too and of all cycling sports weight savings in cyclocross is a good thing imo.

I do the Reston cyclocross race every year and it's a really good one, I believe it is part of a Virginia series. A couple of years ago if I remember correctly a DC messenger showed up on his single speed cross bike and won the B race which was pretty impressive. SS works pretty well for cross if you have the right rider on it. I do most of my racing in NC but the Virginia series is pretty good too.

lunacycle

I've been running either a 38t or 42t (depending on how fit I feel) single ring up front with a Spot chainguard on the outside, and a Third Eye chain watcher on the inside. I have a 12-28, 9-speed cog cluster on the back. I also use a DA bar-end shifter, instead of STI, and a DA rear derailleur.

I run this setup for two reasons, reliability and ease of cleanup. There's just less stuff to attract mud and grit. As for weight, well, when your bike is caked with ten pounds of mud, a couple hundred grams doesn't really mean anything.

cyclintom

So you're convinced that saving 2 ounces on a Class C rider/bike combo that weighs in at 200 lbs is "lighter"?

I do so get the giggles when people like you walk into a high priced bike shop.

You're the sort of guy who buys an $800 Campy carbon crank, $210 Assos bib knickers and $285 Fizik saddles.

RKR

Tom: You said heavier, I said and proved lighter. You've been trying to argue with me over whether it matters but, as you pointed out, I run a double so its obvious I don't care about those 5.85 ounces.

I laugh at people who go buy $500 jeans. Life is about priorities. The people that shop at high priced bike shops have decided that they value a 5 ounce lighter bike over some new clothes or a car payment. Good for them, we should all be so lucky.

I however don't have a campy carbon crank, fizik saddles cost way too much and the assos bibs that I picked up off craigslist for $35 are sweet, you really ought to try a pair.

giantxc

For DC area races check out https://www.midatlanticcross.info/2006.htm

As for your question, last year I ran a 38/48 with a 12/27 cassette and it worked ok, but the front shifting on my bike with top tube cable routing just never seemed right so this year I'm going to switch to a 1x9 set up with a 42T or 44T chainring and an 11=32 or 11-34 mtb cassette