A little fork history for you bigwheels out there:

The orginal steel fork found on the Cherokee six and Tripacers came out of the dusty Tibbits field airstrip out here in Naknek back on the day when it was being used by the Tibbits-Herremotive gang. They came up with the idea and had Wess Landis make them in town. The Tibbits-herremotive air taxi later became a part of Penn Air but Old man Tibbits (George Senior?) retained the STC later passing it on to his grandson Larry Tibbits. Now Wass and his Son Garry (?) had a good thing going with these forks so they were making them and selling them for years using the Tibbits STC. Well, here comes the FAA. Yep, seems Landes, know know as Airglass, does not have any PMA for the forks they have been selling for 20 something years. You can smell the rubber and see the flat spot from here! I should ask Larry how much he he sold the STC to Wess for $$$. Anyway, the forks have been available for about a year now but i think they are a touch thicker and the one used for the cessna aircraft are a touch taller.

There were four types of fork made with two hole patterns: cessna and piper. The original ones had a round bob at the end where the cup slid in. The second group was not heat treated properly and were all supposed to be destroyed; per an AD...I think. The next group was the one I am familiar with on all the Pen Air cherokee six and Seratogas, most of the Cherokee 140 and up, as well as the tripacers out here. The forth being the newest iteration from Airglass.

I pulled a lot of this out of some dusty corners of my mind so feel free to correct any mistakes or omissions.

Rocket

Jeredp,

forgot to mention:
you are going to smear your favorite grease all over all those shiny parts before assembling. I have seen the effects of... idiots...that had assembled them completely dry and then seriously regretting the profanity I was forced to use to extract the corroded parts from each other. Billable hours

I would dry fit the through bolt with the required spacers and washers and then after you have the correct thread engagement drill one end for a cotterpin/castlated nut. This will make later servicing much easer. You might also find that the through bolt is a touch too long so I recommend trimming the 1/4-5/16 to make it nice and tidy.

When you install the block you will be chilling the strut and heating up the block right? You will also need to fabricate a bullet of the appropriate size for aligning the block to the strut as you slide them together. I use a hydraulic press myself and 2.3 pairs of hands. While sliding the block down when it is close I drive the bullet with a gentile ratatat-tat with my 3x rivet gun. All of this happens in about 4-6 seconds.

I have had a couple where the hole did not line up so you get the bullet in one end but it will not go through don't get all hung up. Just drill/ream the strut from the mismatched side with the bullet still in the other.

Don't forget to use an extra long bolt and some spacers for a tow bar; the one they recommend is too short.

I cut the strut with one of those .032 3" CUTOFF WHEELS IN A 90 DEG DIE GRINDER (damn caps lock).

Lets see, whenever I do this I always leave out something important. Oh ya, see thread about bumper...slide uncut hose on before reassembling strut. Also, spacer at top of strut has chamfered end that goes up to capture snap ring. F-tard out here put mine on upside down before I purchased her and she came uncliped!!!!! I use silicone grease for all my strut assembly.

Rocket

ps. G-looper some things are best shared in a PM...or perhaps not at all :/

pps. I watched two guys try to install the block with a rivet gun at one end and other mechanic at the other; one of them went to the clinic for stitches. I think I have pictures somewhere....

So, I installed my nose for today. All went well with the exception of thing. My torque links/scissors have 3/8 bolts and the attach point on the new block is only 1/4 inch. My options would be to drill out the block to 3/8 or make a new bushing to reduce it down to quarter. Has anyone dealt with this problem?

After a call to Airglas, it was determined that the early 172 has "heavy duty landing gear" that includes beefier scissors with 3/8 bolts instead of 1/4". Airglas advised me to install a later model torque link bushing to accommodate the 1/4" bolt. I completed the rest of the installtion this evening. My only complaint is one of the brake pads rubs the sidewall of the tire slightly. Not sure how to address this one. All in all, I love it! And I gained over 4" of prop clearance with the strut inflated to the same height as before!






Before:

After:

Looks good!

Looks great!!

Thanks for posting the pictures, Jaredp.

Question for you: How much weight did it gain with the 8.5 installation?

Thanks!

Tom

Very nice! Much better looking airplane now.

Thanks for the compliments guys!

as far as weight goes, I'm pretty happy, I only gained 18.4 lbs net with the entire installation(keep in mind I had wheel pants). Here are my weights for those interested:

Removed:

Nose Wheel Fairing -4.5
Old Nose Fork -3.0
5.00x5 Wheel and Tire -9.5
Main Wheel Fairing -13.0
6.00x6 Tires and tubes -14.0
Wheel Fairing Brackets -2.5

Total Removed -46.5

Added:
Airglas Fork +13.5
6.00x6 Nosewheel +4.0
8.50x6 Nose Tire/Tube +15.8
8.50x6 Main Tire/Tube +15.8
8.50x6 Main Tire/Tube +15.8

Total Added: +64.9

Net Gain: 18.4lbs

I flew the airplane tonight for the first time since the fork/tire install. My initial impression is that it feels very heavy on the nose. You 172 guys, please chime in on your weight and balance. I also realized that my torque links may need a little more attention, as I had a little bit of shimmy on the nose. When I went flying, I had about a 10-12 kt crosswind and the air was very unstable so I only made two landings and didn't get a realy good feel for the new set up. So far, I am quite happy with tires and fork. My next mission is to ditch my flap gap seals and figure out how to get my cg further aft without adding more weight. Extended baggage????

A Selkirk extended baggage will add 11bs at station 125.

J,

your nose wheel will shimmy regardless if the tire pressure is anywhere near the usual 30 ish psi you are used to. 18 psi should be just right for your nose gear tire. Try it you'll like it! From your photos I am guessing the mains could use a little less pressure as well. She will be a little harder to push around the hanger and tarmac afterwards though.

As for keeping her light on the nose try adding a few fifty foot low stretch lines, a come-along, some stakes or rods, and a small sledge hammer. All this laying in the vary back should offset the increased nose weight and also keep you from getting stuck should you land somewhere you shouldn't have. It has been proven statistically that having said equipment will keep you from ever having to need it, kind of like when you land in the sand and wish you had bigger tires.

I know it is too late but I would think those new Dresser "tundra" tires would have been perfect for your bird.

Almost forgot, for brake disc spacers one can use an old worn disc by simply cutting off the bolt flange and grinding it smooth. Usually one needs two to a side. I just make rings out of .080" aluminum myself.


Rocket

Getting rid of the flap gap seals will definitely reduce your rate of climb by 150'/min. Removing them will NOT help you get off the ground faster. Removing them will reduce your ability to come in short and stop quick.
If the above items are of no interest to you then take the flap gap seal off. If they are of interest then leave them on. My 172 came with them installed and I was talked into removing them by so called experts. Bad move, nothing but reduced performance all around, especially in short field work. Re- installed them and the performance came back. Very expensive learning curve caused by so called experts. My recommendation is spend your money on leading edge cuffs or vg's or things that actually work for you in slow flight.
One big performance enhancer is the extended baggage kit. You can put stuff farther back and get a real good balance to the plane. A little extra weight in the right place will really enhance the performance of the plane.
KenW

Thanks again for the tips guys. Regarding nose wheel pressure, i'm running them all at 22 right now. I will drop them a little and see what that does for shimmy.

I do believe ext. baggage will be next on the list.

It's interesting what you say about the gap seals. I have not removed them yet because of what I hear about the loss of climb. There seems to be so many differing opinions. One plus about leaving them is that it may help keep me from going into places that I cant get out of. I'll have to give this one some more thought.

FWIW, when I bought my P172D, it had only the Madras super droopy tips, which do improve slow speed handling at the expense of some cruise speed (and they look cool! ). Exactly how much is hard to say, because I'm comparing it to all of the other 172s I've flown over the years; on that basis, I concluded that the Madras tips cost about 5 knots. I had flap gap seals installed, for the primary purpose of regaining some of the cruise speed, and they did that--I flight plan for 115 knots, which is roughly 5-6 knots better than before I had them installed.

I'd had the airplane long enough that I could compare its before-installation landing performance to its current performance, and frankly there isn't enough difference to sneeze at. Climb out from lower elevation airports was improved a little, but not a whole lot, maybe 100 fpm at a DA of 2500'; it makes no noticeable difference from higher elevation airports, such as at a DA of 8500' or more.

Bottom line is that I'm glad I have them--pretty good bang for the buck regarding improving cruise speed, without any bad effects.

Cary

Jeredp did a nice writeup for the Knowledge Base.

http://www.backcountrypilot.org/knowled ... wheel-fork