Carbon & gravel?

ohgodnooo! said:

Anyone have experience with riding carbon road bikes on gravel roads? Are they as sketchy as aluminium roadies? I am sorely tempted by a new Trek madone wich I have ridden on smooth pavement, but don't want to be stuck there all the time. Lots of gravel roads where I live that are safer passages than streets/highways.

Chances are that it will survive without a problem (many MTB hard tails are carbon these days, although constructed to a presumably tougher standard).

So the question is how concerned or worried would you be if you nicked a few tubes with gravel scars? 😄

If the answer is "I'd obsess over the structural integrity for days" :eek: , then don't do it. If you don't care, and have the money to spare, then go ahead 😉

If there's any doubt about the quality of the roads, and whether you would worry about the bike, then go aluminium or steel, and save carbon for the open road.

n

nerdag said:

So the question is how concerned or worried would you be if you nicked a few tubes with gravel scars? 😄

If the answer is "I'd obsess over the structural integrity for days" :eek: , then don't do it. If you don't care, and have the money to spare, then go ahead 😉

n

My curiosity was actually about ride quality of the carbon frame. High pressure tires on aluminium frames make for a choppy ride especially on gravel. Choppy equals less traction. I wonder if the same ride quality that carbon shows on pavement breaks translates to a surface where vibration and bumps are constant. Not concerned with integrity of structure. But I don't plan on flying through there either. Just fast enough to get where I need to go.

ohgodnooo! said:

My curiosity was actually about ride quality of the carbon frame. High pressure tires on aluminium frames make for a choppy ride especially on gravel. Choppy equals less traction. I wonder if the same ride quality that carbon shows on pavement breaks translates to a surface where vibration and bumps are constant. Not concerned with integrity of structure. But I don't plan on flying through there either. Just fast enough to get where I need to go.

Carbon has little or no meaurable difference (to any other material) in it's reaction to poor surfaces. It's 9/10 ths BS. If you are only bothered about getting there and you want good traction on bad surfaces, then buy an alloy bike and put on 25 or 28 tyres and run them at 80 or 90. The tyres make 9/10 ths of the difference, the frame makes little enough not to get concerned. Also the geometry of the frame makes a difference, but the material is the last in the line of things to specify to get a decent ride on a bad surface.

High pressure tires with a stiff wheelset on a CF frame rides badly, too. I learned that the hard (!) way - started out with a set of uber stiff Rolf Vector Pros, and got my hands hammered to a pulp by road vibration. Switched to a milder wheelset (Campy Zonda) and 23mm tires, much better. Tubies ride even smoother.

Big problem on gravel isn't the frameset or the wheelset, it's the skinny little tires that just don't give a large enough contact patch to give good control. If you have lots of money, Dugast makes a set of 'Paris-Roubaix' tubies in 28mm, designed for rough surfaces. Around $125 each, the last time I looked.

Well I guess I'll just have to keep splitting the diference between mtb and road bike, or build a cross bike, which is may be more trouble than it's worth. The Tarmac model I rode the other day looks like it has a fair amount of room for larger tires (surprisingly). Going to ride a Roubaix next. Thanks folks.