1. Yes
2. 105 miles
3. 60 miles
4. 200 miles maybe

You know it kinda depends. Riding a 100-miles somewhere with 6-10,000 feet or more of climbing per hundred miles is difficult. But if it's somewhere flat that's not a big deal. I did the Leadville 100 mountain bike race one year (didn't finish). That's 100 miles on a mountain bike on trails that reaches over 12,000-ft altitude. That was rough. You had to finish in under 12 hours. No way I could make it. Neither did my buddy that talked me into it but a couple of other guys in our group did and got the big silver belt buckle to prove it :)

1. Yes
2. 120mi
3. 80mi
4. 150mi

1. Do you ride a bike? Yes
2. What's the longest distance you've ever ridden in a single day? 116 miles
3. What do you consider a reasonable distance for a single day's ride? 62 miles, but only occaisionally
4. What do you consider an INSANE, but still humanly possible distance for a single day ride? 150+

1. Yes
2. 150 miles
3. 100 miles
4. 300 miles

1. Yep
2. ~60km
3. ~100km
4. Anything above 160km (100mi) would be a lifetime goal for me

1. Yes

2. 126 miles (In Spain)

3. 20 miles

4. 700 miles

2b).The Spanish ride was on a rented yellow mountain bike. On my next port of call in France, the bike rental shop tried top rent me a bike with worn through tires (thread showing). I complained.They asked how far I was planning on going. I said I went one hundred twenty six miles last week in Spain. The bike shop closed it's doors and said they had to take a siesta.

4b). Assuming a support van rides with me (not gonna happen).

1. Yes
2. 50 miles on a mountain bike with knobby tires and it was easily accomplished
3. 100 miles
4. whatever Machka says

EDIT: I notice a lot of people put a lower number for 3 than for 2. It's not clear what "reasonable" refers to - are you talking about a reasonable maximum for a charity ride (that's how I interpreted it) or a reasonable distance for a weekend rec ride, where 50 or 60 might be better, or a reasonable commute distance, where it might be 15 miles or less?

1. Yes, I use it to do as many short errands and transportation as possible.
2. 18 miles
3. I don't know. Whatever utilitarian errands I have to run in a day, I guess.
4. RAAM humans do 300+ miles a day.

1. Yes, duh.
2. 128 miles.
3. 50 miles (depends on terrain, of course).
4. 204 miles (one day Seattle-to-Portland).

1. Yes.
2. 140 Miles.
3. 100 Miles.
4. 200 Miles

1. Yes, I do.
2. 20 miles recently, 50 miles many years ago
3.100 miles
4. 200 miles

1, tak (yes)
2. exactly 167.53 miles
3. 20 miles of hardcore
4. 300 miles (possible but probably would take a whole day of riding)

1. yes
2. 115 miles (got briefly lost doing a century, or my longest would've been about 105 :-)
3. Depends on what I'm doing, but 50 miles or so is a comfortable touring distance
4. Insane for me, or insane for Pete Penseyres? :) I'd like to do a double century at some point, but
centuries are about at the edge of my current insanity threshold.

1) Yes
2) 163 Miles
3) 50-60 miles
4) Over 200 miles

1. Yes

2. 462.4 kms (287.3 miles) http://www.machka.net/24hour/2006_UMCA24hour.htm

3. Up to 322 kms (200 miles)

4. Over 869 kms (540 miles) http://www.ultracycling.com/records/timedrecords.html

Why do you ask?

Well, my answers are way different:
1. Yes, yay! :D
2. 20 mi.
3. 20 mi.
4. 50 mi. Unless I was being chased. Then many more, I'd guess.

lol at machka's response.

1. Yes
2. 60 miles
3. 40
4. 100 miles

1) Yes
2) 178 miles
3) 60
4) Is it possible to ride an insane distance in one day?

1. Yes.
2. 120 miles.
3. 100 miles.
4. More than 200 miles.

I'm not sure what you mean by question 3. "Reasonable" might mean "easy for me", or "easy for most people", or "possible for most people", or something else. My response is to that third option.

1. Among other things
2. 226 miles or so
3. As far as I need to go to get where I want to go.
4. However many miles it takes to not be fun anymore.

1. Yes
2. 136km
3. 70km is a nice comfort point. I start to get bored if the ride is too long. If there's good music, interesting scenery and stops, then this limit goes up! :)
4. I wouldn't want to ride over 120km again. Its just not all that mentally satisfying eventually.

1. Do you ride a bike? (I'm assuming almost everyone here does.)
-Yes
2. What's the longest distance you've ever ridden in a single day? (In mi or km)
-100 miles
3. What do you consider a reasonable distance for a single day's ride? (Again, mi or km)
-50 miles
4. What do you consider an INSANE, but still humanly possible distance for a single day ride? (mi or km)
-200 miles (that is to say, a moderately-fit person on an ideal setup could probably go 200 miles in 24 hours.
~

I did 226 in under 15 hours...and I was overweight, over 40 and still a smoker.

1. Yes. Started toying with the hobby in March, slowly am getting more and more sucked in.

2. About 40 miles

3. Reasonable single day's ride...This one is tough.
A decent workout should be at least 25 miles.
A reasonable commute would be no more than 15 miles one way. Mine is 10.5.
A reasonable relaxation ride to kill some time would be 5 - 10 miles round trip.
Grocery shopping more than 1 mile away is ridiculous, in my opinion.

4. Insane, but still humanly possible FOR ME: 80 miles*

*let me experiment and get back to you on #4 :D