This forum is one of the reasons I’ve been grabbed by the unicycling bug. It seems that just about everyone who takes the time to learn to be a proficient rider of a unicycle has a positive, enthusiastic, can-do attitude to life. You Joe have that in spades, you’re like a breath of fresh air - an inspiration.
I’ll chip in and say that I did a century on a 29er before I ever had a 36. It went fine, just a bit of a long day (maybe 18 hours door to door, I don’t remember the detail).
I used 125mm cranks (hadn’t got any smaller by that stage). Not the best option; smaller is easier - try at least 100mm if not 89mm.
If you’ve got a 36 then it is a bit masochistic to do road riding on a 29, but the same argument could be made for having a bike and still using a unicycle at all! Go for it if you want to 
Sam
This from one of the lucky few riding KH36 outfitted with a Schlumpf hub 
“Even”? haha. 
I’d like to see some folks do a true single-track century ride someday along the lines of the abundant trail 100 mile foot races being held all over the country. On this kind of terrain a 36er and even 29er would most likely be suboptimal. From my experience riding this type of terrain I can totally conceive of covering 100 miles on single-track fully within the time frame / cutoffs of a typical trail 100 mile foot race as long as it’s supported i.e. aid stations every 5-10 miles. This I think is the next level in long distance trail unicycling; covering the types of terrain and distance that mtbers do but with the time frame and support of a 100 mile trail footrace (since the average pace would be about the same). I for one am willing to give it a shot. I come from an ultramarathoning back ground so applying to off road unicycling seems like a logical next step for me.
Most of my century rides were not on a KH 36 Schlumpf. My first distance unicycling was all done on a Sun 28. I switched to a UDC Big One 36
two weeks before a back to back centuries required more speed or I would be getting little or no sleep. Now the 28 gets used mostly as a loaner.
Many thanks to Kris Holm who loaned me his personal Schlumpf hub and wheel or I would have been non-geared again for me second attempt at the STP in one day. I only had eight miles on it before my 200+ mile STP event in 24 hours.
I have been watching for a trail century route near me to do. Soon I might try one.
Joe
just wondering who has done the most centuries.