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TR3A wheel hub bolt upgrade....

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K

karls59tr

Obi Wan
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I'm visiting here from the Triumph Forum and technically this is not a racing question. I plan on installing some Shelby 5.5 x15 slot wheels on my TR. Backspace is 3 5/8....offset is 9mm I'm going to have to get new bolt holes drilled into the mags as their pattern is 5" and the TR is 4 1/2. The car is mainly used as a summer driver and the occasional autocross. My question is: can I have 1/2" bolts installed on the hub?(seems to me I saw a pic of this somewhere). Anyone done this?....any stock bolts from another vehicle suitable for this? Will this weaken the hub? Any advice? Karl
 
Karl........

Assuming the offset is correct and with the tire ur using , it fits in the wheel wells.....

Those wheels are ...umm 20 ---25 years old? That said if you want to use wheels of questionable parentage they will have to be double drilled for the now bolt pattern. This may or may not be possible because the pad (the part of the wheel that is the center where the bolt holes are drilled, might not be solid to allow 4 holes. If the pad is scalloped in the rear between existing holes , it cant be done. (safely).

Then, if double drilled, you have a wheel that is cosmetically goofy (to some people). Drilled correctly you will probably be set back...ummm 30? ?40 ? per wheeel. In addititon, then you have to buy 16 sleeve nuts and washers. Installing 1/2 " studs is doable......is there not 7/16" in there now? New or in good condition 7/16 will be fine for what your doing.

Short answer.................buy 4 new wheels.....Hap at Acme who lizzards around this board is your man.
 
Jerry New wheels are probably an option but...(I'm probably flogging a dead horse here but I really like these wheels).......would a 1" adapter plate to the new bolt pattern throw the offset to far out as to be impractical?TR3 offset 6mm.
 
Only your tape measure will tell the tale re the "too far out".

Bolt pattern wheel adapters are an iffy proposition and decent(??) ones might not be cheap. Certainly not for any heavy duty use.

You might comsider that a nice 59 TR is worth a few bucks....treat it to a new set of wheels?
 
JerryB said:
.....Hap at Acme who lizzards around this board is your man.
Click to expand...

Slithring up :smile: :smile: Anything is possible, find yourself a machinist/ good tool and guy man can probably modify your existing hub, make an adapter, and even make you a new hubs, anything is possible these days with machining what it is today, we used to make aluminum hubs for the Spridget race cars. If this is about money, then who knows to make these wheels fit may become more money than new wheels would cost, but if it's not about money, and you really want to use these wheels, then anything is possible as mentioned. FWIW on TR3 in Superlite we sell the +3mm offset for these cars, in a 6" wide wheel, we have several sets out there on the road, with the 6" wheel the +3mm offset work out to be like 3.58" backspacing, so your backspacing with the 5.5" wheel leaves you alittle under a 1/2" to work with on a adapter, and can work on your TR3. If you decide to go the new wheel route, keep me and Superlite in mind, hope this helps.
 
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