I swapped the Goodyear 26's for ABW 29's.
Initially I installed Goodyear 26" tires. These are good tires - essentially a "poor mans" bush tire, but still very capable.
So why change, and whats the big deal with bush tires ?
Well, most normal tires have the valve protruding through the wheel rim. Under heavy braking the tire can slide around the wheel rim, and shear the valve off, leaving you stranded. Bush tires have the valve built into the tire sidewall, and the tube is molded into the tire as a one piece unit. This also enables the tire to be run at a much lower air pressure. They are made of a softer more pliable rubber compound that yields to the rocks and bumps more readily. The Goodyear's had a minimum recommended air pressure of 16 PSI. The ABW's have a recommended minimum of 8 PSI, and many people run them even lower. One large tradeoff is that the softer rubber compound tends to wear much faster if used on tarseal or concrete. Because of this most pilots with bushwheels tend to stay away from sealed runways and aprons.
These have made quite a change. First is the much higher body angle that seems to change the whole look of the aircraft. My main reason for getting them was to reduce stress on the airframe. I probably won't operate into any rougher airstrips, but it will make it easier for the ones that I already operate into.
Taxying
Definitely a softer ride, but with less forward visibility. Given that I already couldn't see over the nose it's not a huge change.
Takeoff
Due to the higher angle of attack, the tail comes off the ground earlier, and with less forward stick. (It still requires alot of forward stick pressure to lift the tail at around 25 kts though). This is very good for operating on rough airstrips, and for increased forward visibility. It's also increased the prop clearance by a couple of inches too.
One consideration is that due to where the tires are located, a small increase in tire size makes a large difference in propeller clearance.
Landing
The biggest change is to the touchdown. It's akin to doubling the suspension and results in a plushness that I found hard to believe. For the first few flights I had 11 psi, but I'm now running 8 psi.
The tailwheel is easier to keep off the ground for longer on landing too. I did notice a slight "grab" on each landing, as if I had hit a puddle of water, but not bad and only momentarily. After a few landings it all began to feel very normal and now I've forgotten what the previous tires felt like.
I also noticed it was slightly easier to touch with the main wheels first. This is somewhat anecdotal and largely affected by approach speed.
Cruise Speed
There is of course a tradeoff, and on my machine I lose approximately 3 KIAS. That's coming from the Goodyears, and sure the difference would be greater if compared to 8.5's. Essentially, if you want speed then you'd want a smaller tire. I'm not in a hurry to go anywhere. My current cruise speed with the ABW's and operated LOP is about 110-115 KIAS.
