JeffOYB

I suppose it's obvious. But I did a very muddy, slippery race yesterday with my roadbike-turned-CX bike using sparse-knob green Vittoria Tigre tubies, 28mm. I thought the bike worked great. But I kept running into the tape exiting turns.

In such conditions I kinda thought that narrow tires were better than wide. Possible?

My bike is a nice light 19 lbs.

But it has road brakes -- I sure didn't have much braking yesterday but I didn't feel I needed it, either. Still, I haven't ever tried canti's or disks so I wouldn't know what I'm missing.

Lastly, I'm using a single bar-end shifter. Moving my hand to the lever often seemed like a pain. It seems like these courses with lots of quick changes are good for brifters. And is indexing smart for CX? I "jangle" gears sometimes and also make big, "coarse" shifts where I end up in the wrong gear -- too hard or too easy coz I'm throwing the lever so much just to try to get it close in such a short time.

If I switched to a CX frame and cantis and brifters I wonder what that would do to my game...

I do have some handmade 30mm Grifo tubies just waiting...

bobotech

I would say the advantages of a cross frame over road frame are first and foremost, the clearance for larger tires (700x32c or larger, most road frames are limited to 700x28c or smaller), and canti/v-brake posts or possibly disc brake mounts, and maybe slacker frame geometry/longer chainstays which will allow for a slightly more stable bike. Also some cross bikes have cables that run on top of the fame instead of under like most road bike frames and maybe the cross frames will be slightly stronger than a road frame.

JeffOYB

So are wider tires always better for CX? ...Wider better for slippery mud? I've heard that some conditions are better for narrow. Maybe also a smoother, faster course would reward narrower.

bobotech

I would say that wider would be better for mud. Smoother, faster, hard packed course would probably be better for narrow tires. Narrow tires in soft surface will dig in and bury themselves in the surface. Wider tires will float more. Seems like all the people I know who ride cyclocross like nice wide tires around 700x32c or larger. Plus I imagine that larger the tire, the lower the pressure you can get away with which would allow the tires to conform to the changing cross track surfaces. Kind of like how mountain bike people want to run as low of pressures as possible. Even occurs with people in their off road 4x4 trucks, they want to run as low as possible pressures without popping the tires off the beads. The problem with running super low pressures on bike tires are the chances for pinch flats.

JeffOYB

I recall reading that narrow tires for mud sink down to firmer trail base. ?

Using a roadbike definitely means TUBIES coz I doubt you can ride a 28mm clincher offroad and not pinchflat at anything less than, what, 80psi. I ride about 30psi in my 28 tubies. Nice! But 32 would still give more contact patch when conditions want that. Probably most conditions do...

Andy_K 

It depends on the mud. For thin mud, everything sinks down. For really thick mud, sinking down is a very bad thing. For squishy mud, the sinking down effect is there and helpful.

Even when you are sinking down to a firm base, you generally want the widest tire that will reach that base so that you maximize your traction.

tarwheel 

You can still run narrower tires on a CX frame if you want to, but you can't run wider tires on a road frame that doesn't have the clearance. Canti or disc brakes also allow much more clearance for larger tires as well as mud-shedding and much better stopping power than calipers. Many CX frames also have a higher BB to provide more clearance underneath.

h2oxtc

I have Schwalbe CX 32c on the front and 30c on the rear. They're a semi-slick with nobbies on the outside edges for cornering. I haven't tried them in real muddy conditions - and would not expect them to be great in soft conditions.

fotooutdoors

One realization I have had on barcons is that, because access to shifting them, I ride almost exclusively in the drops. This changes the bike's fit for the worse (too deep drop), but it often helps with handling.

I say run what you brung until it starts limiting you, though I would imagine that in slightly thicker mud conditions, your road bike would have come to a standstill pretty quick.

fietsbob

Resistance is Futile , you need a race level cyclocross bike.. to be more Pro, you need 2.


if you always ride the same course under the same conditions from start to finish

then a broad generalization of what tires you always need can be thrown around.

idc

It's mostly tire and mud clearance.

Also cabling (for portage, and for reduced mud-in-cables) and perhaps a sturdier/beefier frame (at least when you get to weight weenie bikes).

grolby

The ability to use wider tires is very important. You need low pressure, and wider tires give you the volume to go lower without risking pinch flats. At the widths used in cyclocross, a few millimeters make a big difference in tire volume. A 32mm tire works a lot better than a 28.

obrentharris 

This is true. But if the course has a firm base close to the surface on the first lap it usually won't still have it on the second lap after 100 riders have churned it up.

Brent

hodag

Chicks dig CX bikes more than road bikes.