Need to know offset on original tire rims

[cleistertiger]

Can anyone tell me what the offset was on original tiger rims? At the last stages of resto on 1966 1a and upgrading to 16 inch rims and want the stance to look original.....thanks

Chris Leister
Ormond Beach, FL

 

[0neoffive]

Fresh from the Boot

Can anyone tell me what the offset was on original tiger rims? At the last stages of resto on 1966 1a and upgrading to 16 inch rims and want the stance to look original.....thanks

Chris Leister
Ormond Beach, FL

Just measured my spare. 3-3/4" ish from the mounting bolt holes to the inside wheel rim. Just thinkin' that a 16" wheel ain't gonna give you much rubber kidney protection .

 

[Forrest39]

It's kind of an apples to oranges comparison. If you are putting on 16" wheels, you will likely have a 6-7" width which throws off the backspace dimension anyway. you will have to measure and fit a few options.
While I have 15's on my personalized car, I can share that I have 15x6 in the front and 15x7 in the rear. I don't have the backspace measurement of the rears in my notes, but know that the front is 4.25" backspace. For tires I have 195/50-15 in front and 225/45-15 in rear. Add Koni shocks and Dales high rate springs and as Randy pointed out, it's a bit of a stiff ride. Great for the track though!
If you really need it, I can go pull the rear wheel and measure...
Good luck!
-Kevin

 

[cleistertiger]

Thanks

Thanks guys for the response....so why do I need Kidney protection???
66 1a....total restoration....Ford Racing 302...custom Strange Engineering Ford 9" rear but with custom built four lug configuration so it looks stock. Think I'll need more than kidney protection!

 

[CLIFF_MK1]

Here's a post I made last year, explains what I had to do to put 16" rims on a tiger. Note, I wish I could have gone to 15". Cliff

One of the difficulty in getting wheel sizes that fit within the wheel well with out rubbing on the suspension on the inside or sticking out to far on the outside is that the Tiger front end is relatively wide-not much room to juggle backspace or offset.

The stock 4 1/2 wide 13" rim has a 25.4mm offset and 3.75" backspace. So, the way I see it, if a 5 1/2" wheel had the same offset, it would protrude toward the outside of the wheel well somewhat. Maybe a 1/2 inch? So, to get the 5 1/2" wheel to the same position in the wheel well, you would need less offset. So, 20mm might get you there for the same look. But, this would push the wheel into the inside of the wheel well and potentially rub on the suspension.

The more the positive offset (less backspace) the more the wheel sticks out towards the fender and increasing the width of the wheel increases this effect. You could look at the installed Lat 50 5 1/2 inch installed rim and tire and see if there was room for greater backspace or less offset. There are some tools that allow you to see if certain size wheels fit in the space available. Sometimes this really limits you to what, if any, rims are available.

Dale's front suspension has about the same width as the stock Tiger, so finding wheels that fit over the brake calipers and close to the suspension but are still appropriately inside the fender is difficult depending on what brakes and size wheels are chosen. I made a mistake and ordered 13" disk brakes on my front end. You can't fit 15" rims over the 13" calipers, so you have to go with 16" or 17" rims. Rims are sold by width and size with a small selection of offset for each style. With a requirement of 5" backspace to keep the wheel inside the fender, there was a very limited choice in wheels. There was more choice in 17", but 16" was already pushing it for a Tiger. There is also much less tire choice for 16" vs 17." So if I were doing it over, I'd go with 12" brakes and 15" rims. It's probable that the designers of the 15" Lat wheels made the best compromise they could. Cliff

Old 01-31-2018, 01

 

[cleistertiger]

Thanks Cliff...really appreciate it.....I like these 15" rims but not available in 4x108 bolt pattern....you know anyone besides PS Engineering (cost a fortune) that makes them...seen them on other Tigers....

 

[CLIFF_MK1]

I switched to 5 lug rims so didn't explore what's available with stock 4 lug wheels. Maybe others will chime in. Cliff

 

[Tigergeek]

I just finished the task of fitting 15" rims to my 1966 Mk1A that, after 11 years, is close to being restored. After multiple fitments, on the front is a 15x6 with a 22mm offset yielding a back space of 4.4". I plan on using a 195/50-15. The rear is a 15x7 wheel with a 0mm offset yielding a 4" back space. An alternate for the rear is a 15x6 with a 12mm off set - still end up at 4" back space. I plan on using a 205/50-15 on the rear. The wheels are from VTO in Arizona and are 4 x 108. They can custom drill and set off sets to your specs.

If you want to play around with off sets and back spacing, use the CAD tool at http://www.rimsntires.com/specspro.jsp . Its a great tool posted by Rims-n- Tires. For the stock tire (Chart 1, left side) put in the stock Tiger wheel/tire sizing and off set. In Chart 2, put in the desired wheel/tire size and then play with the offset until you get the backspace desired.

Every Tiger can be slightly different. For my car, a front offset of 4.4" was the absolute max we could go. The rear "might" accept a wheel with something a bit bigger than the 4" back space, but I was being conservative

 

[TAH_Tiger]

Wheel offset

I have:
Front 15x6 20mm offset 4.3 backspace 185/55x15
Rear 15x7 20mm offset 4.8 backspace 195/55x15
No issues, good look.