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Dino Saga 080504 _ Wheel Repair Possible?

Discussion in 'Corbani's Corner' started by John Corbani, May 4, 2008.

  1. John Corbani

    John Corbani Formula 3
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    May 5, 2005
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    John Corbani
    #1 John Corbani, May 4, 2008
    Last edited by a moderator: Sep 7, 2017
    Dino Saga 080504 _ Wheel Repair Possible?

    Tried a good selection of wheel and tire stores in Santa Barbara and got a no or a maybe on a 17” Mesh pattern wheel. Finally came down to the fact that it would take forever to find something. Big Brand Tire couldn’t do anything themselves but they knew of a guy in Newberry Park who knew wheels and Ferraris. Got a name and a phone number and I was off. Had three phone discussions and found out that he had been a principle in a company that made wheels during the 80s and 90s. They shut the plant down in the mid 90s and switched to distributing, plating and refurbishing. He is officially retired but consults fairly regularly as their Ferrari specialist. He knew Gotti and said that his company had put together wheels of the same design. Cast hub, drawn and spun inner and outer rims. Still had lots of old stock. I finally got a quote from GBS, Gotti distributor, for a new spinning. $470 plus shipping. Rather stay close to home.

    I made an appointment to go down and meet the man, let him look at my wheel pieces and let me look at his facility. Thursday I loaded the hub and spinnings into the Dino and headed down. Car was running great but the handling is really annoying with only one decent rear wheel. Will not track dead straight. As soon as you get any kind of curve going it is stable. In a straight line it tracks anything and everything in the road. You are always correcting for something that the car should have ignored. Made the 70 mile run with no sweat. Ran up the Conejo Grade at 80 with lots of oomph left over. Newberry Park is right at the top of the grade so had to be ready to slow down and bail out.

    Yes, they had an impressive facility. Big warehouse with wheels stacked 40 ft high on padded shelves. Nice offices, loading docks, machine shop. Looks like most of their business is in 4 x 4 off road custom wheels. Most are huge, and heavy. Most all were chrome, their specialty. http://wheelconcepts.com/ Met Wheel Concepts and was impressed. We looked at my wheels and it turns out that my wheels predate anything his company had done. He supposed that my hub had been originally designed for 13”-14” rims and was sized for much smaller forces since it has only 16 bolts holding things together. He said that later Gottis had much bigger hubs, 32 bolts and much shallower rims. But the design and basic construction was old hat for him. Had sold, repaired hundreds and still had some tooling; and still had a machine shop and folks who knew how to work drawn and spun aluminum.

    Went out to lunch with them. Discussed things and he thought that my inner spinning was in pretty good shape compared to what he had repaired in the past. Liked the TIG welding but the spinning had never been straightened properly after welding. And he didn’t trust my selection of bolts. Offered to fix bad spinning, refurbish everything else. If I liked it, could refurbish other three to the same quality. Quoted price for all 4 wheels, first one at ¼ the total. Price was right. I bit. Will be smarter or wiser or sadder next week. Stay tuned.

    John
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  3. dave80gtsi

    dave80gtsi Formula 3
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    #2 dave80gtsi, May 5, 2008
    Last edited by a moderator: Sep 7, 2017
    John – While not a Dino owner, I’ve recently completed a very similar R & R project on a set of vintage Gotti J55C 16” rims for my 308.

    These wheels, just like yours, came with sixteen (16) rim attachment bolts between the rim and the center hub spider.

    I’m curious to learn more details concerning why this number of bolts is now thought to be inadequate for the need.

    The original Gotti rim bolts were a high strength M6 metric bolt. In my case I replaced these during my R & R work with new ¼” (6.35 mm) diameter Grade 8 fine thread bolts and matching Grade 8 nuts, simply due to the better availability of the ¼” size here vs. the OEM metric M6.

    Let’s assume that the weight of one of our typical cars is (say) 3200 pounds, and that during an especially tight turning maneuver, 100% of the entire weight of the car is somehow magically forced onto only one single wheel – most certainly a “worst case” scenario. This would result in a tension force of around 200 pounds per bolt x 16 bolts. The resulting tension in these ¼” bolts with a 200 pound load works out to be about 4000 psi, which is a very safe working stress level, especially for the Grade 8 rim bolt material that I would recommend for this sort of critical application.

    I will concede that current fashion does show most modern wheels to use more than sixteen (16) bolts. But I put forth that this is done more in the name of style and appearance, rather than as an attempt to correct an inadequate number of bolts.

    Thanks and Cheers - DM
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  4. John Corbani

    John Corbani Formula 3
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    Dave,
    Thanks for the thoughts. Your wheels look great. I have to agree with you that the 16 bolts should be enough but there are other things that happen. Something very traumatic happened to that one wheel time and time again. When I really measured the rims I found that the outer rim had bulged out between bolts. Wonder if some damn fool seated the beads with 130 psi air. I know that 40 psi is the recommended max. Then, the inner rim had a crack that went directly through a bolt hole. Can't figure that one but bet it had something to do with removing a tire with only a few bolts holding things together. Those tire bead breakers can destroy a soft spinning. The other wheels prove that the wheels are conservative if not mistreated. The two right wheels have been trouble free. Both left wheels had a hard time before I bought the car. Cracks in both. Left front fix has been totally trouble free since welding in 1987. Left rear has been a problem for last two years, just fine before then. I like your selection of 1/4-28 class 8 bolts and matching nuts. Should be great. There is an argument for a larger spider and doubling the bolts makes sense to keep bolt spacing constant as the diameter goes up. Lower profile tires and larger brake disks you know.
    John
     
  5. BigTex

    BigTex Seven Time F1 World Champ
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    Interesting.....I am sure my Etioles use the same center as thes Gottis, it even has the two oval recesses in the spokes..they do have a much greater quantitiy of perimeter bolts...

    I have never had trouble with them but only have four, so do not have a spare.......

    I wonder if this vendor could build one to match??

    Hope this works out, for you to salvage your good rims!
     
  6. Red 27

    Red 27 Formula Junior
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    Hey John and Dave,,
    I have these rims J55C on my 75 Dino 308gt4 and they started to crack on the outer rim section around the bolt holes. The bolts are very strong but the outer rim piece was the weak point. Gotti replaced the outer rim section and added a bolt between each bolt at no cost to me.
    This was back in 1985 + - and the rims have been fine since. They now have 32 bolts each.
    Dave
     
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  8. John Corbani

    John Corbani Formula 3
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    May 5, 2005
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    Thanks Dave. My left front had cracks around the bolts when I bought it in 1986. No service available then so I welded a 3/16 plate on the inside and threw away the Gotti spacer. The weld was continuous on the outside of the bolt holes so held air just fine and was stronger than the wheel. Has been good for last 22 years. No other wheels showed that cracking. The car was raced and maybe the left wheels spent too many hours bouncing over tires and rumble strips. Like the idea of 32 bolts. The left rear outer rim had bulged between bolts but no signs of cracking. I will watch carefully now that wheel seems fixed.
    John
     
  9. dave80gtsi

    dave80gtsi Formula 3
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    Thnaks for the heads-up.

    I plan on keeping a very close eye on the Gottis. and will be using them only for street use.

    For the odd track day I'll reinstall my QV replicas which have a separate set of stickier tires mounted on them.

    Cheers - DM
     
  10. Red 27

    Red 27 Formula Junior
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    Good luck to both of you. Your cars look great.
     

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