Need Help - First Time Bungee Replacement

[jsimmo97]

Good Golly.... bought some new 60" green and blue stripped bungees from John over at Kitfox.... tried to get 6 wraps but there is no way that is going to happen.

Question... is there a technique? I tried the vise grip deal with zip ties but how on earth do you get six wraps and a "30 minute" install. I must be doing something wrong. I got five wraps in about 4 hours.

Please lend me your advise and experience.

~Jason

[Mnflyer]

Hi Jason, as you have found I don't think its possible to get 6 wraps with the 60" bungees I have 70/72 in bungees and 6 wraps, I think I'm not home but will check when I get home if someone has not added a post.

[lbushrod]

I got a set from the McBeans for my model 2. I could only get 5 wraps until I tried a new trick but it takes two people. I took 1/4" nylon rope and saddle hitched to each wrap. With one pulling and one holding I think I could have gotten another wrap yet I put in six.

I was told you should max weight your plane and still not stretch the bungees past 1/4" at the center to the plane. My fox lands differently now with more bounce but I cannot blame that on the plane. Good luck.

[partsproduction]

I took the sagging bungee off today and found two things that shocked me.

One, the rubber strands of the core were all broken adjacent to one of the crimps, the sheath fabric was all that kept it from coming apart!

It gets better,

Two, the safety cable was broken too! So, a few threads of nylon were all that kept the plane from a very nasty and expensive landing.

I had assumed that the bungee was just stretched, so I continued flying the plane!

For the record, the bungee sagged before the hard landing that broke the cable, a friend was flying and came in too low and hit a berm at the end of the grass strip, that broke the cable.

When I first saw the bungees I was amazed that they were crimped like a cable, and this experience fortifies that view. I'm going to buy some blue/blue/green shock cord and experiment with other ways to secure the loops at the ends that don't include stress risers like a crimp does.

[jsimmo97]

Just a follow up... (I was the original author of this post). I spoke to McBeans and they said that 5 wraps is good for the current bungees that are selling these days. They are more heavy duty than the originals. Let me know if you find otherwise.

Happy Landings!!

~Jason

[Av8r3400]

Jason,

With the 5 wraps, are the gear legs up tight against the stops or do they slack a bit at rest?

I need to replace bungees on my 1050 and want to know the best way.

[jsimmo97]

Mine stayed tight against the stops with 5 wraps and that's after 2 hours of stretching in an attempt to get 6 wraps.... I have a 1050 as well.

Let me know what you end up with. I'll also take pics and send them over tonight.

[lbushrod]

Deb McBean told me that 5 wraps were sufficient. After several landings with close to gross I could really feel the plane rock in the wind and I had 1/2" stretch at the centerline with that weight.

Using that saddle hitch method got me an extra wrap (6) plus on the "seasoned bungees."

I caution against going for 7 wraps as that will take a lot of the shock absorption out and possibly bend your frame on a hard landing.

With six wraps my gear does not sag from center, gross load, yet still has spring when I rock the wings on the ground.

John and Deb know best and 5 turns was all I could get at first. I am happy with six.

Good luck,

Pete