Is there a reason why no companies are manufacturing front suspension for cx bikes?
I would like to know if a light weight, low travel (<80mm), skinny stanchion (<28mm) would make any difference to speed when off-roading. Comfort wise I imagine the difference would be huge.
I have seen a picture of Lemond racing with a Rockshox fork so definitely been thought of in the past for road bikes.
Cyclocross courses are (generally) too smooth and relatively fast to warrant the use of suspension. Sure, it might be more comfortable, but the added weight would only slow you down and leave you behind your competitors on a typical muddy course.
Note: I don't do cyclocross, so this is mostly speculation.
I'd guess its primarily a weight issue, as well as the culture of the people who do cyclocross. I did find a manufacturer doing rear suspension though.
This link is also interesting reading. The author first notes that suspension would make the ground contact better, but the weight or geometry changes seem to be problems.
From that link, I'd like to quote from that article "UCI rules make no prohibition against suspension in cyclocross or road bikes, and road bikes with suspension forks have been used in UCI-sanctioned events before." In particular, it references this article on how suspension was used in the Paris-Roubaix and how the culture didn't appreciate suspension at first. They also note that current bike design focuses more on tube shaping and carbon fiber.
You could probably find a short travel fork designed for a hybrid bike and put that on your cross bike. However, I havn't seen this happen at any races that I've been to. It's more typical for non-pro riders to use a mountain bike instead of a cyclocross bike to compete in cyclocross races. The shocks do soak up a bit of pedaling effort, which is why they tend to be less desirable. Most modern MTB shocks can be locked out, and that's probably preferrable for the terrain of most cyclocross courses.
Your best bet to reduce the effect of bumpy terrain is to adjust the tire pressure according to the conditions. You may want to consider tubeless tire systems to prevent pinch flats at lower pressures. Smooth tracks will warrant high pressures, but rough courses may be more optimal riding at lower pressure.
Pro races set tire size limit to around 33mm, however most non-pro events have very loose restrictions on actual tire size. So consider running larger tires at lower pressure if you are concerned about the jarring effects of the ride without suspension.
Besides weight, suspension robs you off energy when pedaling, by compressing when you push on the pedal (and rebounding between strokes so the energy spent compressing is wasted). Pedaling is obviously more important in cyclocross than MTB, hence no suspension.
