To a European a cobble is a smooth round stone firmly set in the roadway
<nods> I know these well from my travels in Belgium over the years and especially in Flanders, where they're really rough and yes, firmly seated.
Those stones in Dan's photo looks like a firebreak with a load of pre-gravel sized rocks spread across it to make it passable for logging trucks in the rainy season.
This is "medium" ballast, Andre; the "big" stuff uses rocks the size of shoeboxes. It is that large to cover the exposed dirt and mud left by the first pass of the Caterpillar bulldozer and so provide all-weather traction for the log skidders and such that come later and pull and winch the logs to the trucks for transport to distant mills. In many cases, such ballast never has need to be covered with ordinary (say, "3/4 minus") gravel on limited timber sales.
The bike goes as well over such large ballast but it requires more time, patience, and bike-handling skills to do so and speed drops as a result.
I've included some photos below showing a bit more of the kinds of roads I can expect here in the mountain ranges. The weather can change drastically when you cross the passes and hit the incoming moisture of coastal weather systems at altitude -- in this case, I summited to find myself in snow on the other side. Someone was not so lucky in parking while hunting deer the year before -- a tree fell on their truck and then it then burned, making for a nasty surprise on the owner's return.
I've noticed how far forward your mudguard (fender) covers the front wheel and now understand why you need such a long mudflap.
The extended front mudguard is not originally a front, but instead is a repurposed rear 'guard. See:
http://thorncyclesforum.co.uk/index.php?topic=4523.msg23847#msg23847http://thorncyclesforum.co.uk/index.php?topic=4523.msg23939#msg23939It ends with a lot of ground clearance. You see, when I ride on singletrack and cross-country, there's obstacles such as downed trees that require I dismount and lift-roll the loaded bike over them. If the 'guard ended too close to the ground, the rigid mudguard blade would snag and either distort or crack (both have happened in the past), so I deliberately ended the 'guard high -- and then attached a flexible mudflap so it can provide good coverage against spray and still easily bend rearward if it hits an obstacle. The "flour scoop" sort of mudflap is also too rigid and will damage the mudguard if it snags going over a log or down into a roadside drainage ditch or heavy brush.
The longer forward curve of the repurposed rear (now front) mudguard contains and directs water down and forward so it exits with less velocity, rather than straight ahead where I run into the spray thrown forward off the top of the tire.
On my more road-based randonneur bikes (the ones I regularly take on 300-400km day rides at greater speed on pavement), I have more ordinary SKS or similar front mudguards with very long mudflaps so even at speed, the spray zone is directed below the entire lower chain run of my derailleur drivetrains. As a result, I enjoy long intervals between chain cleanings even after extensive rain riding -- relubing alone will do nicely as there is almost no thrown road grit that ever reaches the chain. I'm a huge believer in long mudflaps especially for my desert tours, where they work as nicely in the dry to prevent alkali desert soil from being thrown onto the chain, keeping it cleaner much longer.
Best,
Dan.