Landing gear weight

[Doggitz]

Hello everyone!

I put in a deposit on a 7 SS about a month ago. Due July 2020, can’t wait to start building. I have this dream (spelled - hallucination) that I will do some “gentle” back country flying with it - not up to cowboys level, but I want to give it a try. I want to build it asp an LSA. I have been looking at videos and doing as much reading as possible. I really like the shock monster/cabane v arrangement. I have time in cubs, so I’m somewhat familiar with how a cabana works and feels. I have virtually no experience with Grove. I have flown Aeroncas with spring gear.

The combined weight of my wife and I, full fuel, and 25 pounds of camping gear would come to about 520 lbs. using the current LSA maximum (AOPA AND EAA say it’s going up) of 1320, that means the build (I plan a 914 engine) can be no more than 800 lbs. does any one have figures on the relative gear weights? I plan 26 inch tires and likely a bushwheel tail wheel, maybe a Beringer anti ground loop tail wheel.

i would appreciate any thoughts.

Thanks

[Av8r3400]

I won't be popular for this answer, but I see no realistic reason for the "shock" style gear for most situations. If you are doing extreme STOL, off-airport ops, maybe, but for most it is a lot of money, excess drag, and complexity.

I am running Grove spring gear and couldn't be happier with the system for my needs. You can look at my YouTube channel and see how the gear works for me.

[HighWing]

I once contacted Grove to determine the installed weight of their gear for a Model IV. Their website at the time indicated 25 lbs. for the gear. I was told that including mounting brackets and hardware it would be a little over 32 lbs.

[Esser]

Cabane gear is a couple pounds lighter than the Grove (Grove is close to 40lbs I think) but slower. I have a 914 powered Model 7 with a lithium battery, constant speed prop and when I did the weight and balance on 26" tires it came to 878. I have a new project I'm slowing picking on and my goal is under 800lbs and I'm going pretty extreme on the plane's diet to get there. Not to say it isn't possible but just to be realistic, you need to be conscious about saving weight everywhere you can.

[fastfred]

Can you share the list of what you end up doing to it? Hopefully the FAA with boost the gross weight up petty soon for the LSA and won't be an issue for me. I rarely would ever get myself in afield short enough to have a problem. Why do you need it so light with all that power ?You must be off in 150 feet most days?

[RV6flyer]

Cabane gear is a couple pounds lighter than the Grove (Grove is close to 40lbs I think) but slower. I have a 914 powered Model 7 with a lithium battery, constant speed prop and when I did the weight and balance on 26" tires it came to 878. I have a new project I'm slowing picking on and my goal is under 800lbs and I'm going pretty extreme on the plane's diet to get there. Not to say it isn't possible but just to be realistic, you need to be conscious about saving weight everywhere you can.

Josh,

I am building a 5 with a 914/Airmaster. Do have a weight & Balance that you could share with me? What tailwheel do you have?

[Delta Whisky]

I've captured reported weights for some time now and as of now my very limited data base shows:

						w/o outliers						w/o outliers
Model		KF4		KF5		KF5		KF6		SS7		SS7
average		676		841		820		906		836		827
Max		793		1,013		890		906		963		878
min		560		777		777		906		736		763
sigma		76		69		35		0		56		33
count		5		9		8		1		19		16
The columns labels "w/o outliers" represent me taking out variants caused by what could be "scale dreaming" and heavy engine choices but still only makes a 9 pound difference for the SS7.
BTW - when I converted to TK-1 shocks (only, not their gear) it cost 8 pounds.

[michaega]

The zipper 1484 big bore kit will give you 114 hp, add the performance cam and that will bring up to 120 hp. The cylinders are a thing of beauty if your a gear head like me with better finning. Of course I didn’t stop there I have the SDS electronic fuel injection and variable timing also by SDS. Not having a dyno available to me like the Zipper folks have, I can only guess another 5 hp or so.
Pulled out my W&B for the Kitfox 7, it’s 826lbs (nose dragger) with Grove gear, magnum whole airplane parachute, MGL 10” EFIS, a210 com, transp, and iPad.

Zipper makes a bigger bore kit but I still like looking out and seeing the wings in the right place.

btw: I have no stake in either company.

[GuppyWN]

The zipper 1484 big bore kit will give you 114 hp, add the performance cam and that will bring up to 120 hp. The cylinders are a thing of beauty if your a gear head like me with better finning. Of course I didn’t stop there I have the SDS electronic fuel injection and variable timing also by SDS. Not having a dyno available to me like the Zipper folks have, I can only guess another 5 hp or so.
Pulled out my W&B for the Kitfox 7, it’s 826lbs (nose dragger) with Grove gear, magnum whole airplane parachute, MGL 10” EFIS, a210 com, transp, and iPad.

Zipper makes a bigger bore kit but I still like looking out and seeing the wings in the right place.

btw: I have no stake in either company.

I’ll be in San Diego Thursday and Friday. I’d like to chat about your upgrades if you’ve got time. I can rent a car and come up. PM me if that is doable.

[Doggitz]

Thanks to everyone. I’m hoping to get the plane around 825 empty weight. May not be possible with options and reasonable avionics.