Cessna 120/140 wheel extension

[babyace]

I have seen wheel extensions on Cessna 120/140 to move the wheels about 2 or three inches forward to put mor weight on the tail. I want to use something simular on my baby ace can someone give me a discription (material and dementions) Mike

[martymayes]

I have seen wheel extensions on Cessna 120/140 to move the wheels about 2 or three inches forward to put mor weight on the tail. I want to use something simular on my baby ace can someone give me a discription (material and dementions) Mike

The Cessna wheel extenders are 5" long by 2-3/4" wide by 5/8" thick, made from steel plate. Combined weight of both extenders is 5 lbs. They move the axle forward 3". They have eight holes, two holes in one end are counterbored for clearance with the original Goodyear brake disc clips. Counterboring is not necessary for Cleveland brakes. The original axle bolts were 1/4" dia., later they were increased to 5/16". There is substantial shear forces on the bolts that hold the extenders to the gear leg, which was the reason for up sizing the bolts. I think that will prove to be a challenge if you are using the stock baby ace gear.

[martymayes]

If you put a bathroom scale under your tailwheel now, what kind of reading do you get?

[jam0552@msn.com]

If you put a bathroom scale under your tailwheel now, what kind of reading do you get?

I agree with the above - if you move your gear forward, you are putting even more weight on the tailwheel. That, in turn will increase the tendency to swap ends if the tail begins to come around. The most easily controllable taildragger will have the maximum percentage of the aircraft total weight on the main gear wheels and only a minimum amount of weight on the tailwheel (50 lb. or so).
-Joel Marketello

[WLIU]

The original post does not give a reason for wanting to move the main wheels forward.

I will suggest that weight on the tailwheel is a trade-off. As is the position of the main wheels. Moving the main wheels forward will make the airplane more resistant to nosing over. Moving the main wheels forward moves the CG a little forward. The weight on the tailwheel will increase, but not by a lot. A few, and I mean 5lbs or so, more pounds on the tailwheel will not make the airplane significantly more likely to swap ends assuming that the vertical fin and rudder are the right size in the first place.

Last month I threw my Pitts up on the scales. Empty weight is 1058 with 62 lbs on the tailwheel. Weighed my Swift a number of years ago. Empty weight 1366 with 37lbs on the tailwheel. Much easier to nose over the Swift. I will guess that the weight that you want on the tailwheel is actually a percentage of the empty (or gross) weight.

So what is the goal?

Best of luck,

Wes
N78PS

[babyace]

The goal is to keep the Ace from nosing over. It does not have a tendency to be really "mean" on the ground but I want to go to an 0-200 to replace the Cont. 65 The plan calls for a standard J-3 gear. That was the reason for the questions on mod. Thanks for the reply. Mike

[babyace]

If you put a bathroom scale under your tailwheel now, what kind of reading do you get?

I get 35lbs with a wood prop. but I am going to an 0-200 engine and I think the tail will be even lighter. Thanks for the reply..Mike

[martymayes]

I get 35lbs with a wood prop. but I am going to an 0-200 engine and I think the tail will be even lighter. Thanks for the reply..Mike

How much when you sitting in the plane?

[cluttonfred]

+1 on the suggestions to put the engine on first, then do a W&B check as well as measure the weight on the tailwheel. You may also find that going with a heavier tailwheel or moving a battery or ELT further aft is enough to balance out any changes because of the long lever arm.

[babyace]

Thank you so much for the info...and for the reply...Mike