Road bike off-road?
 

What is the most aggressive terrain you have tackled on your standard (non-gravel or cx) bike? I'm thinking of those with 28mm or smaller tires.

I've ridden some pretty tough single track, fire roads etc on 25's. I really enjoy riding gravel through the the Rocky Mountains of Colorado. Less traffic and the scenery is amazing. Here are a few pics that I could find. Not too aggressive really but this particular road has close to 5K feet of gain in 10 miles and tops out near 12k feet above sea level. The last mile or so is 15% grade. 25's would be the minimum for sure.

http://i66.tinypic.com/2zipx6u.jpg
http://i64.tinypic.com/igde2r.jpg
http://i68.tinypic.com/svjfdl.jpg
http://i65.tinypic.com/5lqnt4.jpg
http://i66.tinypic.com/ddbxo4.jpg

I ride some routes with up to ten miles of reasonably well maintained gravel like this....

https://www.dropbox.com/s/j3tx0i7e49...el002.jpg?dl=1

https://www.dropbox.com/s/c81j5m5g0a...el001.jpg?dl=1

On a 2002 Fuji Roubaix with 23mm Vittoria Rubino Pro III Slicks as pictured. There are a few short sections of 12-14% where I sometimes can't get traction and have to walk. PITA in cleats.

https://www.dropbox.com/s/ndr0n1xzix..._9069.JPG?dl=1

Impossible. Neither of those bikes can handle that terrain. You MUST have a gravel bike or you AND the bike will disintegrate!

There's an utter lack of terrain here, all roads, no matter how remote, are at least chipsealed or rolled gravel. I did, however, ride a cross bike with road wheels and 28mm tires through fields. It did fine till I hit some particularly wet mud and sank. 30 years ago 28s were the cx norm.

I have been riding my 2016 Tarmac thru unmaintained shoreline gravel paths, on zipp 202's and 24c s-works grip ton race tires, and have yet to puncture. The tires are severely scarred and torn tho'.

I was really surprised how they held up and handled even @ 95psi

Fixed gear track bike on Gatorskin 23's on a rooty and semi rocky section of hard packed single track. That was kind of dumb.

I ride tubulars and have never in 50 years been afraid to take it off road. Obviously I can't do anything technical on a road race bike, but I've sudden single track, and rutted, washed out roads that would have a mtn goat nervous. narrow tires aren't a problem as long as the base is packed and dry. They become impossible in sand or mud where they can't get support.

got hooked doing it on the Rapha Gents Race LA

tubeless 25c tires, 100miles/12k vert and 30/8k of that was on dirt
https://farm8.staticflickr.com/7311/...9f79a330_c.jpg

Belgium Waffle race training last yr, 25C tubed tires
https://farm8.staticflickr.com/7596/...fcf3d187_z.jpg

http://i.imgur.com/Pb2WIZ1.jpg

http://i.imgur.com/RxceDDc.jpg

I've done this road last week on my 23's Luganos. Wasn't planned to be honest, went exploring and it ended up being quite fun and different.

So jealous of where you live. Sensational view. I can smell the fresh air from here.

A track bike on a hiking trail - a leaf- and twig-strewn hard pack dirt path through the woods, but not really any rocks or roots to worry about. It was fairly level, and the climb up to it was paved.
Avatar photo is race bike caught in sand - a stretch along a bike path that was damaged by a hurricane, since repaired I believe.

Off-roads are not the same. On some, even cx-bike is inadequate.

I've done rocky rooty single track. Gotta go slow to prevent pinching, more like trials riding than mtb. And if the surface is too soft or slippery for the skinny tires, you're walking.

For fun, check out the Martyn Ashton and Vittorio Brumotti vids. Here's one:

I can't remember the distance, but at least several miles of packed/slightly loose dirt with a steel bike on 25 tires. I only had to walk it at the end when the road turned to big chunky loose gravel for about 20 yards.

I ride gravel roads similar to those posted here fairly regularly and without much hesitation. I've done some more serious offroad on a few occasions, but that was more survival than actual riding.

My road bike and track bike both take 700x30 cx tires so I ride those when I'm planning a lot of gravel or single/double track. I'll ride similar to what's posted on a whim with 23s though. Unless it's super muddy or deep fresh gravel it's no biggie. Those jagged rocks @jsigone posted might scare me off though.

Years ago I did a bunch of the Tree People trails in the Santa Monica Mountains on my Gilmour; 12-speed, friction shifting, complete with sew-ups.

Went out and bought a Stumpjumper the very next day...

I value my bike and my teeth too much to tackle some of those "roads" in the pictures.

It's really not hard on either. It does require a bit more attention, and willingness to adjust speed to conditions, but IMO not dangerous to either the bike or rider. In fact it might be safer since one is less likely to be over confident, and crash speeds will be lower if/when you do.

@FBinNY is pretty much correct. Just gotta take it a little slower and choose your line. Traction on steep climbs is actually the biggest challenge with skinny tires.

Large chunky stuff tends to cut up nice tires though. I try to stay to the well groomed stuff. The mud in post 10 and rocky stuff in post 9 are too much for me.

that 2nd pic is well traveled, there is a line through the rocky mines, but it's only 4-6" wide at most.

Lower tire pressure, stronger side walls and see good lines. Oh and don't turn your bars suddenly to turn.....haha

https://farm2.staticflickr.com/1668/...04ed0611_z.jpg

SLATE!!

For me the real issue was the gearing on my road bike; it just wasn't set up for those hills...

There have been races over roads that have not been paved, for Years .. early Tour De France is an example ..