Two high volume featherweights
I tried out a couple new tires last night which I had great hopes for. Both tires are really light and fairly wide. Here are my preliminary reviews.
Vredestein Bull Lock 26x2.35


I bought this tire based on the advice given to someone else looking for a high volume tire under 1000g for riding a bike on snowmobile trails. He was told that they were in the 660g range and measured as wide as some 2.7s
My tire weighs in at 680g and is 62mm (2.44") wide at the casing. That is a whopping 990g lighter than my Gazz, talk about loosing weight in a hurry.
I was riding the tire on my Nimbus/Echo 46mm wheel, Dual 165/137mm cranks in the 137mm position, and my new KH26/29 frame. I would have used 145mm cranks but they were on my 29" wheel which I was going to test next. 137 turned out to be a good choice since the light weight tire made it much easier to control with short cranks.
The first thing which was really noticeable was the light weight. As being ridden the unicycle weighed in at 6.2 kg. a full 2kg lighter than the steel frame and Gazz combo I am so used to.
Riding around it felt pretty good and absorbed the lumps and bumps OK but as soon as I started to test how it did in the hopping department I bottomed out right away. I added quite a bit of air and now the tire just felt hard. Some people like a hard tire, I am not one of them so I let air out until I could feel the tire give when hopping hard and the tire would not quite fold if I side hopped. this was somewhere around 30PSI which is a bit higher than my usual 20-22PSI.
I chased the dog around the yard and the tire just felt alive. It was very quick and stuck to the ground like I was running in cleats. I missed the soft rebound of a Gazz but the tire was really responsive. It took very little effort to turn, stop, speed up, or otherwise change my momentum and had incredible grip. I am thinking that this tire will become my preferred tire for rides on loamy rolling trails and suspect that it will also do really well in mud.
Schwalbe Racing Ralph 29x2.4


This is the ultimate in big and light. Measured on my 50mm speedway rim the tire was 63mm (2.48") wide and weighed in at only 590g 
Using the same frame and just swapping the wheel the unicycle was now down to 5.7kg. I think I might be turning into a weight weenie, but not enough of a weight weenie to loose the steel post mounted handlebar that I use.
I had similar experience to the Vred Bull Lock in terms of light weight and sidewall stiffness. I settled on 35 PSI with this tire. It had a bit more stability side to side but bottomed out a bit easier than the Vred at the same pressure. I think the side stability is from the slightly narrower tire being on a wider rim.
If the Vred was fast and responsive the Ralph was, um FAST AND RESPONSIVE. Seriously a tire this light with a light weight rim and 145mm cranks made for a very easy to control wheel and the rolling resistance was so low it almost felt like it was propelling itself.
The grip was good on hardpack and damp ground but it would wash out a bit if turning really sharply in looser stuff.
So a supper light and fast 29" tire with great volume but not the best for hopping and mediocre grip. I had previously used a WTB Prowler tire on this wheel and think that I prefer the WTB for the thicker sidewalls and better grip even if it is a bit smaller and heavier.
Conclusion
If you got a 26" MUni for XC rides what don’t involve a lot of hopping or dropping Go to Jenson USA and order yourself a Bull Lock (68% off). Very light for their size and it has great grip.
If you really want a light weight 29" tire the Racing Ralph seems OK but so far I think I preferred the WTB Prowler which is not really that much heavier but has a more solid feel with better grip.
Edit: While Gazzalodis are the hot topic I will throw in my experience. I have been riding a 26x3 Gazzalodi since 2006. It really did suck before I got a wider rim as it would just fold over then throw me when mounted on an Alex DX32 rim but I love it on a wider echo rim. Now that I have a decent rim to use with it I decided to upgrade my frame and got a KH29 frame and it is too wide. 3.15" and won’t fit between the legs without rubbing. When I am using my Gazz I am stuck using my old steel frame but in a lot of ways the weight is worth it.