zipties securing smooth hubcaps keep burning up?

[Geo Metropolis]

Hi, I'm new to the site (you can read my intro in the introductions forum) so I apologize I can't yet post pics. For my third aeromod I decided to do smooth wheelcovers.
I had trouble locating the correct size pizza pans so I simply cut circles out of 1/8in ABS that I had bought for aeromodding. I tied a string to a marker then taped the string to the plastic so that the length from tape to marker was exactly 7" then used the string as a rudimentary compass to trace a perfect circle. Follow that up with a boxcutter and I had a great looking disc.
I used disc 1 as a template for 3 more. To mount them I simply drilled 3 pairs of holes then ran zip ties through one hole, around and behind the spoke of the rim, then back out the other hole where I connected the zip ties. In reality Each pair of holes has 3 zip ties to get the length right because I drilled small holes and used small zip ties. I cut small access points around the valve stems but otherwise they are completely smooth.
The problem is that the zip ties aren't lasting. The driver's rear wheel is particularly troublesome. I've had zip ties break on 3 different occasions and they are only 3 weeks old. Today I literally fixed a broken set before I left for work only to have all 3 sets break on that wheel on the ride home. The good news is the disk flew up and got jammed in my rear wheelskirt so I didn't lose it, the bad news, my tire rubbed it the last mile or two and practically melted it in half
I think I'm going to try wiring them on with some stainless wire instead. Any ideas why the zipties fail so easily? My guess is the heat from the brakes but it's weird that one wheel seems so prone to failure. And it's really hard to imagine the brakes get that hot since I try to drive like they're not there. The cover flew off on a freeway run where I was definitely not using the brakes. I really don't get it?

[BamZipPow]

Different qualities and load strength of the zipties. Are these brand name or some generic stuff? What's the load rating of the zipties you are using? You might want to go with zipties that have a higher load rating.

Wire is a good start...but it may evenually break do to the flexing/rubbing. Got any piccies of yer setup?

[Geo Metropolis]

is it possible that there is an insane amount of air pressure trying to escape from inside the wheel out? I suppose that's another idea.

[Geo Metropolis]

The zip ties are from Wal Mart so I'm not sure how to answer that question. They are the small (like 6"ish) ties so I doubt their load strength is very high. I like the wire idea because it won't require a tool to undo in the event I need to remove the tire (the zip ties really need a knife of some sort) I'm still a lurker status (<5 posts so I can't put up pics yet) I'll try and post some pics tomorrow

[Rokeby]

The "miniature" zip ties, the ones with a cross section of about
1/16" x 3/32", have a "loop tensile strength" of 18 pounds.
The next size up, "intermediate" size, is 40 pounds. The
"standard" size is 50 lb. See here for actual tie dimensions:
3M Zip Tie Data

I have used these for many years for securing plywood parts in
"stitch and glue" small boat building process. If the little ones
break, just drill more holes, use more ties and close them up a
little at a time so that no single tie sees the whole load. The
alternate of course is to enlarge the hole and go to the next
larger size tie. All three sizes are generally available at Home
Despot, Lowes, etc.

This is when securing a roughly circular cross section wire bundle.
There is a significantly lowered value when the tie goes around hard
edged corners, essentially an arc of zero radius.
So, give your corners the largest radius that you can.

NEMA

[BamZipPow]

The Walmart zipties are known as a cheap ziptie and doesn't hold when you need it to. Yer gonna need to invest on some quality zipties if you want things to hold in a stressed situation.

[Vekke]

I have used 4 zipties in my hubcaps and had zero problems. The width of my zipties has been 4.8mm or 0.188". These have had enough grip in my car. Also you should consider drilling the attachement holes as close to the outer edge as possible. This way its hold much better.
02062009570.jpg - Windows Live

[SentraSE-R]

I think you're all barking up the wrong tree. There has to be some tight clearance that's rubbing on the zip ties on that one wheel. Jack it up and rotate it. I'll bet you'll find some interference.

[TomO]

Originally Posted by Geo Metropolis

The problem is that the zip ties aren't lasting. The driver's rear wheel is particularly troublesome. I've had zip ties break on 3 different occasions and they are only 3 weeks old. <snip> My guess is the heat from the brakes but it's weird that one wheel seems so prone to failure.

I would check to see if that brake is hanging on the vehicle. Jack up the car and spin that wheel it should spin freely since it's the rear. then compare how many times it spins on its own to the passenger side. If you have access to a non-contact IR temp gun, that would be the quickest way to tell if the brakes are hanging on that side.

Originally Posted by SentraSE-R

I think you're all barking up the wrong tree. There has to be some tight clearance that's rubbing on the zip ties on that one wheel. Jack it up and rotate it. I'll bet you'll find some interference.

It could be this as well, either way, some jack time is in order

[cfg83]

Geo Metropolis -

I used 4 small zipties on a plastic wheelcover too :

http://ecomodder.com/forum/showthrea...-diy-9158.html

http://www.youtube.com/watch?v=8ZEBjzB5l5g

I used 4 zipties because my wheel has a design pattern that has 4x4 holes. However, my cover thickness was maybe 1/16", so the zipties were not holding much weight.

My design has a slight conical shape that made the edge slant *into* the edge of the wheel. For you I am guessing that the air may be getting in and "pulling" on the edge of the wheelcover. Can you have someone pace you in another car and watch their behavior?

CarloSW2