Shopping for a new tailwheel spring

[rocketman2tm]

28372

So I sheared a tailwheel bolt over the weekend. Didn't even notice it until the next preflight. I have since replaced the bolt and have flown the airplane without any issues.

I know that the one piece aluminum spring gear was designed with this failure point in mind and I flew with one in the Stick and Rudder plane and thought it felt pretty nice. Is there any reason to skip this solution and go straight to the T3? I have to believe the aluminum saves a couple pounds at a very long arm. Back of the envelope math tells me I'll give up about 5 pounds of baggage capacity with the T3 vs the leaf springs I have now. I assume the aluminum is close in weight to my current setup if not slightly lighter.

Thoughts?

[jiott]

The Grove aluminum spring and the T3 are two very different animals. The T3 purpose is a cushioned, non-rebounding tailwheel for unimproved surfaces. I am not convinced it is as tough or much tougher than the Grove. The Grove aluminum was developed as a much stronger upgrade to the leaf springs, but no attempt was made for cushioning or rebound; in fact the Grove is a little stiffer and harsh compared to the leaf spring. In my opinion, if you need the cushioning/non-rebound then the T3 is the way to go. If you are just looking for more strength and toughness and cost is important, then the Grove is great (I have had one for about 4 years with no issues).

[Delta Whisky]

Not to hi-jack this thread (but, I guess that I am) - is the Grove tail wheel spring lighter? How much?

[jrevens]

When I compared the weight of my original 3-leaf steel spring assy. vs the T3, the T3 was approximately 1.5 lb. heavier... that's all. I do like the T3 very much. I increased the size of those 2 bolts to AN4 (1/4") vs the original AN3 also. The T3 allows a tail wheel first landing technique without the rebound which can make very short landings a little shorter for me. Another advantage is less stress on the fuselage back there. Just some points to consider.

[GuppyWN]

When I compared the weight of my original 3-leaf steel spring assy. vs the T3, the T3 was approximately 1.5 lb. heavier... that's all. I do like the T3 very much. I increased the size of those 2 bolts to AN4 (1/4") vs the original AN3 also. The T3 allows a tail wheel first landing technique without the rebound which can make very short landings a little shorter for me. Another advantage is less stress on the fuselage back there. Just some points to consider.

Agree to all and I immediately noticed less jarring on the tail on rougher strips. Definitely like that aspect.

[alexM]

Not to hi-jack this thread (but, I guess that I am) - is the Grove tail wheel spring lighter? How much?
I have the Grove aluminum tail wheel, which is currently on my plane but coming off soon so I can start covering. I'll weigh it when it's off. Like the Grove aluminum main gear there's nothing particularly light about it, it's just simple and tough.

I know the T3 is "all that" for heavy duty use but the places I land are routinely served by planes with all varieties of tail wheels and none break off. If it's really rough the tail wheel should spend minimal time on the ground anyway. Maybe I'll upgrade later, who knows.

[Benbell4140]

Does anyone know anything about this aluminum spring? It doesn’t appear to be a grove spring. I have one just like it and was curious to hear any good or bad reports. It came with a second hand tailwheel that I purchased.

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[jiott]

It looks to me like the Grove aluminum spring.

[DesertFox4]

It is a Grove spring. Had one on my model 3 for about 800 hours. Worked great.

[n85ae]

I had that Spring, it is a Grove. Grove told me to throw it in the trash, as a number of them have broken. I had
a custom built 3 leaf made by a spring shop, basically same dimensions as the Grove, but 5 degree steeper bend
the Grove was a very harsh spring.

I replaced my mount bolts with 1/4 NAS bolts

Jeff



Does anyone know anything about this aluminum spring? It doesn’t appear to be a grove spring. I have one just like it and was curious to hear any good or bad reports. It came with a second hand tailwheel that I purchased.

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[PapuaPilot]

I had the thick Grove aluminum spring and only used it during construction. I was super stiff. Now I have the T3 and love it.

FYI I wouldn't enlarge the TW tab holes until the original holes get elongated. They only need to hold the side load or shear load of the spring and the AN3 bolt is fine.

[airlina]

I had the thick Grove aluminum spring and only used it during construction. I was super stiff. Now I have the T3 and love it.

FYI I wouldn't enlarge the TW tab holes until the original holes get elongated. They only need to hold the side load or shear load of the spring and the AN3 bolt is fine.

Phil, I don't disagree with you much , but i do disagree that the AN 3 bolts are sufficient in this application. There were several failures back in the late 90's when I was building and many guys started drilling the holes larger for a AN 4 bolt which is what I did during my build. I also got rid of the tubing in the original design and made a solid aluminum bracket that wraps around my leaf spring. Even with all that one of my AN 4's sheared a few years back, so this is a known common failure point that should be checked closely on every preflight easy to miss the missing bolt and if you don't catch it you're probably in for mr. toads wild ride on your next flight. Also as Jeff mentioned the aluminum grove gear from our era (late 90's kits) are suspect (again several documented failures with rudder damage as the result and a big fix.) I ran mine for several years until a fly in when another Series 5 builder who had his fail , made me promise to replace mine, which I did with a 3 leaf steel spring that works fine.

[jiott]

My AN3 tailwheel clamp tab bolt sheared from side load. Replaced it with AN4.

[jrthomas]

I've been thinking about the Grove tailwheel spring for my model 4. It originally came with a 2 leaf but I replaced it with a 3 leaf during construction. After about 5 and a half years it seems to have sagged a little. Some years ago I had a tailspring break on a friends model 2 so I'm naturally a little gun shy. I tend to be a little on the tail heavy side so lighter is better. I use both paved and grass strips, nothing rough so the T3 is not needed. I know that the Grove that Kitfox sells is for models 5 through 7. Mangy Fox adapted one to his model 4 and seems to like it. I guess what I'm looking for is advise. Is this a good upgrade? Also what's involved in adapting the Grove? I have the Grove main gear with 22" Dessers.

[n85ae]

There have been several of the original Series 5 builders who broke their airplanes from those AN-3's breaking.
I guess it's open for debate as to "why" they broke, but nevertheless they did. The cost of AN-4's is miniscule, and
reaming the holes, and making new spacers is trivial ... So that's what I did.

Next step will be adding some weldment to reinforce the tabs which are also known to break off when you least
expect it ...

The original Grove Spring that Skystar provided I talked to Grove and their reply was fairly simple:

"The safest thing you can do is remove it."

Regards,
Jeff


I had the thick Grove aluminum spring and only used it during construction. I was super stiff. Now I have the T3 and love it.

FYI I wouldn't enlarge the TW tab holes until the original holes get elongated. They only need to hold the side load or shear load of the spring and the AN3 bolt is fine.

[Delta Whisky]

Phil, I don't disagree with you much , but i do disagree that the AN 3 bolts are sufficient in this application. There were several failures back in the late 90's when I was building and many guys started drilling the holes larger for a AN 4 bolt which is what I did during my build. I also got rid of the tubing in the original design and made a solid aluminum bracket that wraps around my leaf spring. Even with all that one of my AN 4's sheared a few years back, so this is a known common failure point that should be checked closely on every preflight easy to miss the missing bolt and if you don't catch it you're probably in for mr. toads wild ride on your next flight. Also as Jeff mentioned the aluminum grove gear from our era (late 90's kits) are suspect (again several documented failures with rudder damage as the result and a big fix.) I ran mine for several years until a fly in when another Series 5 builder who had his fail , made me promise to replace mine, which I did with a 3 leaf steel spring that works fine.

I see the fender washers under the front attach point. Done to change the angle of the trailing spring angle? To solve a problem I might have? Inquiring minds want to know. :D

[n85ae]

I believe Bruce welded a plate under the original tabs after having a weld breakage. So likely the washers are compensating
for the additional metal in the back to keep the Spring angle correct.

I'm sure he will post a reply.

Jeff


I see the fender washers under the front attach point. Done to change the angle of the trailing spring angle? To solve a problem I might have? Inquiring minds want to know. :D

[airlina]

I see the fender washers under the front attach point. Done to change the angle of the trailing spring angle? To solve a problem I might have? Inquiring minds want to know. :D

Darrel, Jeff hit the nail on the head with his response, after ski flying season ended last spring and I was removing my tailski, I found that one of the tailspring mounting plate tabs had cracked along the factory weld , so I fabricated a steel gusseted doubler to beef up this area (my era Series 5 did not have the beefed up version that I believe the factory is doing now) . I always thought this area of the Kitfox was a bit wimpy with all that goes on back there especially on unimproved runways and while skiing and I was proved right , even though it took 18 years . Hence the spacers are required to make up for the doubler thickness. As a side note i saw your great looking plane at Sentimental Journey -nice job, quality work and it really stood out in the parking row even though we were the minority among all the Pipers. (2nd photo is the original break and 1st photo shows the doubler ready for install- was a tough area to weld due to the restricted access and fabric repair was required after a bit of expected meltage.)

[Delta Whisky]

Thanks for the kind words on the plane Bruce. I tried to keep an eye out for you - hanging around your good looking plane maybe - but no joy. We'll have to keep an eye out for fly-ins somewhere between central PA and northern Virginia and plan an in-person meet up.