Online Community of Zenith Builders and Flyers
I have now broken two rubber bungees in two years. I am very disappointed in the quality of the last two bungees. They are junk compared to the original bungee I cut off only because I thought it was time to replace it after 5 years. I wish I never would have cut it off as it would likely still be giving me good service. The vendor changed the internal rubber band type to fewer, but larger bands and they just do not hold up. I have a light engine and do not pound down heavily on the nose gear so this lack of bungee life irks me. Because of this latest event, I am biting the bullet and bought the Viking steel bungee. It appears from the discussions I have seen that the hardest part will be drilling the welded metal cap off the nose gear leg. I think I can even keep the gear leg installed to the firewall during spring installation, which will save a few hours.
Wish me luck,
All three of my bungees came from Zenith. They were all supposedly made to the same MIL-spec that the ones from Spruce and other vendors are made to. I am sure if I left my original bungee on, I would probably still be using it and wondering why all these people have been switching to the steel spring. Unfortunately, I do not have the luxury of partaking in a bungee durability study so I decided to painfully fork over $400 for the spring. I hope you got a good bungee and it gives you many years of faithful service.
just flew my first flight today with my new Viking bungee. Last bungee was showing signs of deterioration after 2 1/2 years and 200 flights.
took me half a day too drill out my top cap. Used a 1 3/4 inch milwaukee hole saw from Home Depot.
Other than that make sure the post fits the straps before you install the straps, don't ask me how I know.
And make sure you paint the spring, you would think for $400.00 it would come painted.
I am not sure what you mean by making sure the post fits the straps. The bottom of the strap fits to the crossbar and the top end goes through the top block. If you could enlighten me on what tripped you up, I would appreciate it.
The pos was the wrong term,I mean the cross bar, I had to open the holes up a bit to get the straps over the ends of the cross bar.
OK, I understand. I see it has plenty of extra edge distance to account for some cross-bar size differences. I think the prototype units came with a cable wrapped around a thimble and swaged. I could see how this would have caused much bigger issues with size differences. The current design helps counter this.
Both bungees that failed were within same year of production as when I installed them and the next year they were failed. I still have the original packaging with dates, but not in front of me now. The original bungee was supplied with my kit, so it was like 3 years old at install and 5 years later, was still going strong when I replaced it just due to age.
Yikes! My new bungee from Spruce arrives tomorrow!
I just replace mine, but I picked it up at Zenith. The other one hadn't been used, but the kit was dated so I thought it should be replaced.
I have now installed the steel spring and flown with it 6 times. Total installation time was around 5 hours, but I was not in a hurry, so it could be done in less. Removing the nose gear end cap was less of an issue that I thought. A 1 3/4" hole saw from the hardware store and liberal application of oil during the drilling only took 5 or so minutes. It took more time with a dremel to clean up the little bit of metal that remained the tube end to smooth it out.
The hardest part was working with the pin through the gear supports. I shed a little blood on that one.
I ran an electrical firewall penetration smack dab in the middle of my firewall so I had to rework some wire routing. Here is the new steel spring bungee installed.
With the nose gear off the ground, I adjusted the two side nuts down until I got a rudder feel that felt just right to me. Subsequent flights confirmed the feel and and I have not re-adjusted it yet. Landing on pavement and smooth grass, there was no perceived change in nose gear bounce during landing. On a rougher grass strip, I felt more bounce than with rubber. Also, during the bounce cycles, there is a mechanical clunk heard and felt when the spring hits full extension. That is just something to get used to. I was not able to compress the nose gear and spring fully in the hanger to see if that center threaded rod would touch the cowl at max travel, but a quick measurement showed it would be real close. Just to be cautious, I cut about 3/8" off the end. For now, consider me another satisfied spring customer who recommends it to anyone who is tired of bungee breaks.
Your install looks nice. Jan of Viking Aircraft Engines is very creative. We have not tested yet, but glad we installed ours during the build.