SunFlower

I went to a cyclocross race in my neighboorhood over the weekend and it looked really fun. However, I noted that most of the guys were riding what looked like converted road bikes. They had road bike handle bars and road bike frames but with thin knobby tires. Only one guy was riding a traditional mountain bike.
How come they do that ? I assume the bikes are lighter but they looked like maybe they couldnt decend or corner as well.
I plan on entering my first race in 2 months and I was curious about the bikes. I will be using my traditional mountain bike.

M_S

Seriously?

SunFlower

i lived in missoula for 3 years and i found the people there to be generally more articulate than "seriously".

M_S

Let me expand upon my previous question: Do you seriously think that you are the first person to ask in what way cyclocross bikes differ from road bikes?

Cyclocross bikes are not converted road bikes. They are cyclocross bikes.

I hate to say it, but do you think you're the first person to ask this? I've found most people in Missoula also know how to use Wikipedia:

Cyclo-cross bicycles roughly resemble the racing bicycles used in road racing. The major differences between the two are that cyclo-cross frames have wider clearances, knobby tires, cantilever brakes and lower gears. Also, a heightened bottom bracket was typical 10+ years ago; now many cyclo-cross-specific frames do not have elevated bottom brackets. Many cyclo-cross bicycles are set up with a single chainring and chain "drop" guards. A single chainring allows for a tighter chainline, thus redcuing the chance of throwing a chain on a bumpy course.

https://en.wikipedia.org/wiki/Cyclocross#Bicycles

threeflys

easy there M S....

Sunflower- Yes, there are specific bikes for cyclocross, which look similar to a road bike just typically more useful for errands and stuff like that. People do use Mtn bikes in cross races also, probably not a bad idea if you're unsure if you want to get into the sport seriously.

A lot of people buy a cross bike as their road bike also and just switch the wheels and/or tires out depending on what they want to do. You'll find a cross bike with cross tires will do a lot of what a hardtail mtn bike will do also and it would be great training for bike handling skills...

Take a look through some of the threads here and don't be discouraged by asking noob questions, we ALL have at some point...

Chris

SunFlower

thanks for the info threeflys. i have a road bike that i never use and now wondering if i could turn it into a cyclo bike. its a low end diamondback so could i just put different tire on it ? i assume i would have to adjust the brakes to fit a bigger tire and wheel ? whatever i did i would want to do it for cheap since i am not hardcore like most of the guys.

AndrewP

The higher bottom bracket was to stop the toe clips catching on the ground in case you were using the reverse side of the pedals. Some cross bikes have modified top tube shape to make it easier to carry on the shoulder - light weight is also a consideration here. I use a cross bike for commuting as I want to be able to take potholed roads and dirt paths, but dont want the weight of a tourer. Some cross races dont allow disc brakes and bar ends.

flargle

While the OP could have shown a bit more initiative, the bit about "I assume the bikes are lighter but they looked like maybe they couldnt decend or corner as well" is valid IMO.

We don't really know what the "ideal" cross bike is, because UCI rules require drop handlebars, forbid disc brakes, and limit tire size to 35mm. Even though the vast majority of us aren't beholden to these rules, they certainly influence our equipment choices.

If the UCI all of a sudden let go of all their restrictions, here is what I guess would happen:
- The basic geometry of frame and fork would remain the same. Given a typical cross course, it makes sense to run big wheels, not have suspension, keep the bike light, and a relatively big main triangle (for portaging).
- Many pros would start using straight/riser bars. They already spend the vast majority of time on the hoods, might as well run a simpler setup. A lot of (most?) pros mountain bike race during the summer. Thomas Frischknecht was very successful using flat bars before the UCI forbade them.
- They'd continue to use cantilever brakes. Discs add weight and their stopping power is rarely needed. There are no long descents in cross.
- Tire widths would get a bit wider, maybe toward 40mm.

That's just my hunch. Point is, I think it is a reasonable thing for us amateurs to question some of the common "wisdom" concerning equipment.

flargle

The UCI doesn't allow disc brakes, but I have never heard of a non-UCI race disallowing them.

Almost all cross races forbid bar-end extensions, because they face forward and are considered a safety hazard.

M_S

I didn't mean to come across as quite so harsh...

well, maybe I did. As Flargle put it, it was the lack of initiative on the part of the OP to learn even the most basics about cyclocross bikes and racing before asking a rather vague question that really irked me.

But I should have stated the information in my second post up front.

SunFlower

i didnt even know there was such a thing as "cyclocross" until after the race that i saw. i assumed it was mountain biking and the particular guys i saw had just modified or converted their bikes.

flargle

If only there were some convenient way of hunting down information on an unfamiliar topic.

That would be really awesome. I mean, if such a thing existed.

SunFlower

haha. okay, i think its time the a.s.s holes here start getting over how superior they are and get back to being internet champs. you win.

threeflys

You might be able to convert your road bike and use it for a while, it depends on how big of a cross tire you can put on it without rubbing. I tried putting my cross wheels on my Soma Smoothie ES for grins and they were rubbing...and that's with long reach brakes. Cross bikes usually have more clearence and use canti brakes to allow for mud clearence, however since you're in SoCal I don't think that will be an issue...

The tires will really be what may limit you in using your road bike, you may be better suited to staying with your mtn bike and using the skinniest knobby you can find.

Aeroplane

I know it's getting off-topic, but to follow with this thought exercise... if folks were running flat/riser bars, they'd definitely run V-brakes.

127.0.0.1

OP

ride an MTB all you want in any non UCI cyclocross race. if you like cross you will get a cross bike
when you are good and ready.

and to make a cross bike out of a road bike ? just run your road bike as-is. you might slip
in grass and mud, so you see you have to throw on cyclocross knobbies -- if they fit the frame--. the frame is the problem on a road bike

and the second problem is mud clearance for the brakes...road bikes don't have that room


but hey run yer MTB a lot of people start that way, or have pit bikes which are MTB. if you
start to dig cross there will be people selling used cross bikes all the time (at the big races)

darksiderising

I doubt this because of mud-shedding issues.

fuzz2050

I wonder how it shows lack of initiative to post questions in a forum dedicated to cyclocross racing?

shapelike

Well this thread is a complete trainwreck.

Ronsonic 

Fuzz and Sunflower this thread's a disaster so now that it's in the ditch I'll pedal even harder.

It is disrespectful to ask someone to type a bunch of stuff special for you when there are entire encyclopedias and FAQs full of that stuff already there for your benefit. It really is a bit of an insult to the value of other people's time and effort that you think they should work out an executive summary just because you're too damn lazy to just pop open google and type "cyclocross". The first link answers almost all your questions.

If there are follow up questions, please, feel free. But honest, none of us show up here as volunteer info-serfs. Our time and carpals have value to us.

Back to the original poster. "Traditional mountain bikes" have existed for about 30 years, cyclocross has been happening for over a hundred and has always used drop handlebars and diamond frames. The cross bikes are lighter and just plain faster.

SunFlower

HAHA. wait, seriously ?

get_nuts

You're not going to be able to put big enough tires on your road bike. Your mountain bike won't be at that much of a disadvantage in a beginners' race, especially if you put narrower tires on it. Look for 1.3-1.5 inch tires. Schwalbe makes some. The thing that will determine your success the most is your technique. Practice quickly dismounting, running over a log (or two logs) and remounting as fast as you can. Good racers will put in huge gaps in a dismount section on you. Try to limit it. Practice 180 degree turns - go towards a tree, and try to take the tightest turn around it that you can, and head back to where you came from. Take it so tight that you will fall a couple times. Then you'll know what you are capable of. After your first race, you'll have a better idea of what you need to work on.

Brian Ratliff

The ideal cross bike will change according to the course and conditions. A full grass UCI course will suit a road racing bike with file tread, 25 or 27c tires. The same course but in January with mud, snow and ice will probably bring out the hardtail, rigid fork mountain bikes. But it's not about having the "ideal" bike. It's about people competing against people - equipment being secondary. You know, the same reason why you don't get to use your hands in soccer or the reason why you must dribble the ball in basketball.

Ronsonic 

Yep, seriously. Cyclocross has indeed been around for about a hundred years.

flargle

Yup, pretty much Netiquette 101.

More than anything, you just come off like a ****** if you tromp into a forum and immediately start asking superobvious questions that any google or wikipedia search would have answered.