35" Bushwheels on Helio? Still pretty quiet. Spar Carry thru?

[Flathorn]

Anyone have actual experience with 35" Tires on a Helio? Overkill? Saw a pair for sale , and was interested. Spar Carry thru? any more info?

[AlaskaGrown]

I spoke with someone that has used the 35s and he really liked them. Although they aren’t approved for the Helio and I’m pretty sure they aren’t approved for the weight. But the guy really likes them, until they pop on him.

[Jason Stephens]

There is a 35" designed for the Beaver/PC-6 which according to the website has a stiffer sidewall to allow for use in aircraft up to 5600lb GW.  They weight 60lbs each though vs 45lbs on the regular 35".  Maybe a call to Airframes Alaska would be best to see what they think is best.

[RCarter]

I don't have experience with a Helio on 35s, but I have seen one or two and have sat in them (which means absolutely nothing!).  That said I am convinced the 35 is a bad idea for a Helio.  I say this not because the tire is a bad option but there are two very large and looming unresolved issues that are still present.  First issue is brake capacity and second issue is the tail.

The Brake issue might be able to be resolved with a grove 10" wheel and is most certainly resolved with a Berringer wheel off a pilatus ($$$$, custom machined axles, and more $$$$$ not to mention paperwork).  Neither is certified for a Helio that I am aware of and I am not sure if the grove wheel is the right width for a 35.  The Airframes 10x10 wheel only uses the disk from a 6" cleaveland/airframes wheel and it is only attached by 3 bolts.  Not enough braking capacity and certainly not enough strength in the parts to accommodate the torque loads applied by the lever arm of a 35" tire and the Helio weight.  I have a suspicion that part of the reason N77TR crashed a few years back was lack of braking authority to keep it straight (zero proof on that one, just pure speculation).

Second issue with the 35 is floating the tail.  Any where you land that requires either the floation or diameter of a 35 is going either cause the tail to sink like an anchor or will be rough to the point that the stock Helio tail cant roll over the obstacles.  That being said, a Zaegel tail wheel fork will probably solve that problem if you can find one.  An 800x6 (850x6 maybe?) on the tail might give the appropriate deck angle to match a set of 35s.  I know the 600x6 works quite well with 31s.  Not sure what the new loads imposed on the A-frame attach points are with an 800x6 on tail, but that much lever arm probably stresses something.  The Beaver folks who run the larger tailwheels often joke about how the bigger tail wheel works pretty well, but when it fails it rips out a whole lot more metal and bulkheads then when a stock tail wheel system fails. Bigger wheel -- bigger problems.

Not to say it won't work, but there are bigger issues at play that merely tire size. Berringer wheels and brakes off a pilatus with 35s and a 800-6 is probably a pretty good set up.  But then you have 150+lbs of rubber hanging off the airplane and something in the range of $30K invested in wheels, tires, and what not.  If you got the time, money, and inclination to go for it and post a picture. I want a ride in it if you do it!