Bigger tires equal heavier nose?

[PilotPaul]

Hello all,

I have been using here for a few months and I think this is my first post.

I bought a Kitfox series 5 over this past summer and have been flying it a TON! I absolutely love flying it. I live right on the Mississippi River and spend most of my time landing on sandbars and gravel bars. As such I decided to put some ABW 26"s on it. They look great and really dampen things out. I weighed and computed a new weight and balance for it and the empty weight comes in at 909lbs with an empty CG of 11.02. I do have 1° forward sweep on the wing to accommodate for the O200 engine.

My question is, have any of you noticed a heavier nose in flight after installing bigger tires? I'm not running out of trim but I just don't like how heavy the nose is now. If you have had to deal with heavier nose, what did you do to compensate for it?

[PapuaPilot]

I have a nose heavy model 5 too. My EWCG is around 8" and I run out of trim when I put full flaps in. The only way I know of that will fix this is to put some ballast way back in the tail.

Have you also considered that part of your nose down pitching is caused by the drag of the bigger tires which are below the CG?

[Av8r3400]

The weight of the tires should not effect the nose heavy situation, since they are right on the CG, but the drag they cause will give a nose down moment.

What style trim do you have? A trim tab or the "all flying" horizontal stab?

[PilotPaul]

Thanks for the replies. I guess I hadn't really thought of the cg dropping or the drag the tires would cause in the sense that it would cause a nose down moment.

I have the flying stab. Not a trim tab. It isn't bad really its just different than what it used to feel like. I guess I'm just going to have to get used to it.

[GuppyWN]

909 empty! You have a "real" engine on it?

[jrevens]

909 empty! You have a "real" engine on it?

I tend to question the accuracy of that also, especially since the airplane has an O-200 up front. How was it built to be so light?

[alexM]

I tend to question the accuracy of that also, especially since the airplane has an O-200 up front. How was it built to be so light?

909 is light?

[jrevens]

909 is light?

I don't know what I was thinking... you're right Alex. Mine is 819# empty w/912 ULS. I was looking at that and thinking "809" I guess.

[rogerh12]

Because I have a tri-gear plane with a heavy alt-engine, I placed a lead rod in the rudder vertical post.
It was quick and easy to do, and in that position it supplies the best counter weight, with least amount of overall added weight.
Roger