Anyone running 7.50x16's behind a 21 stud?

[Talkwrench]

I need to order new tyres soon and Im hoping to get the correct size. My little 21 stud is a good engine just don't want to kill it by oversizing the wheels. currently I have 6.50 on the rear and it zips along nicely BUT iam damn sure I would have 4.1 gearing [its a pick up] so it seems to be working hard on the freeway. So Im thinking either 7.00's or 7.5's ??

If anyone has pictures of these sizes on their vehicles I'd like too see..

Also how will I go using the tubes I have are they specific to size?
Front rim size is 4" x16 rear is 4 1/2" x16

[1932 V8]

Here are some number to think about . These are all with 4.11 rear gear and 1.1 trans.

29" tall tire @ 3ooo RPM = 57.25 MPH
30" tall tire @ 3ooo RPM = 59.22 MPH
31" tall tire @ 3ooo RPM = 61.20 MPH

Not a lot of difference as you can see so a 7.50 will help on the freeway and if your 21 stud is ok now I would assume it would do fine with a 7.50 tire.

FYI my 7.50-16 tire is 31" tall

Also , your 6.50 tube will not fit a 7.50 tires as far as I know .

Good luck !!

[Mart]

I have ran 7.50's and 4.11's with a 21stud absolutely no problem. I still do, in fact, in my 33.
Tubes normally fit a range of sizes, I believe you can use a slightly smaller tube in a slightly bigger tyre, but don't do it the other way around.

Mart.

[Lawrie]

If your 21 stud is OK it should do it easy,in my 33 with the 21 stud,it has the 3.78 rear gears, 525x17 tyres,and it tows my home made caravan a treat,
Lawrie

[Bassman/NZ]

These are my 7.50x16s with my 5.25x16s.

[my4dv8]

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As said 750s will do nothing but good. Of course if you do have 4.11 gears it will still scream but will sure be less. Ultimately for the big Aussie plains you need 3.54 gears and 7.50 , even with the original three speed it will still humm along nicely at the legal speed. .
4.1 x 60 x 366 = 90036 divided by 31 = 2904 rpm
3.54 x 60 x 366 = 77738 divide by 31= 2507 rpm

[Talkwrench]

Thanks for the pics and info guys.. I was looking at the 7.00's but from the Firestone figures its only 1/2 " bigger for the 7.50's so roughly 31 1/2" . I did try some 10.5R x 15 from my mates jeep on the back, they would be 31" and I could pull away at 20 MPH top gear without to much problems.
I think I might miss not having to change gears going around corners

[Bruce_MO]

I had 7.50 X 16's on my '52 pickup for years until a week ago. Changed to 6.50 X 16's and I'm MUCH happier. It rides nicer (4ply vs. 6ply) and I had occasional shimmy when I hit a certain type of bump. I also got tired of the "1-ton" look of the truck sitting noticeably higher.

The tires are substantially heavier, and that was the trigger of the shimmy. Sure, there was some wear in the steering box that I couldn't adjust out, but it wasn't all that bad. King pins, tie rod ends, brgs, etc were all new, but if you have a bit of wear, I would suspect that the heavier 7.50's might cause some issues. With my lighter 6.50's, I can't make the shimmy happen.

Just my opinion...

[JM 35 Sedan]

I have Diamondback smoothed faced blackwall radials on my Avatar '35 Fordor sedan. 550 x 16 Michelin's on front and 750 x 16 Yokohama's on rear. I changed the rear gears from 4.11 to 3.78 last May before going on an EFV-8 Club Cross Country Tour. The engine is basically a rebuilt (0.030" over bore) original 21 stud '35 with babbitted mains. The car runs just great with this setup. Drove about 12,000 miles in 2013. I will see if I can find some pics to add here later.
Two pics from my tablet files. I will try to find more to post from computer files tomorrow

[Talkwrench]

Bruce Im just talking for the rear, I will change to 5.50's for the front. Big 'n' little's.

John .. radials.. where what how?? Just wasn't aware you could get radials in these sizes? Pics would be great just want to see how 7.50's look stuffed under the rear..

[Talkwrench]

Update; Just fitted the 7.50x16 on the rear and 5.50x 16 on the front. Turns them no problems, changing gears seems better too. Wasn't cheap but better than changing diff ratios..
Fill the guards nice!

[Brian]

Looking good...Have you got an Indian too?

[danliveshere]

Hey looking good Rob.

[34s4ever]

I'm running a set of 750's on my 34..Makes it a lot easier on the engine at highway speeds..The little 21 stud pulls it along just fine..

[JM 35 Sedan]

Originally Posted by Talkwrench

Update; Just fitted the 7.50x16 on the rear and 5.50x 16 on the front. Turns them no problems, changing gears seems better too. Wasn't cheap but better than changing diff ratios..
Fill the guards nice!

Who's tires (tyres) are they, manufacturer? Are they bias ply or radials? They do look good!

[bluardun]

An FYI:
I talked to the people at Diamondback Tires this morning. They are in the process of manufacturing a Radial tire that looks like a vintage bias tire. It is their AURBURN CLASSIC tire. They are behind on introducing it on the market. It "should" be available in August (2014).
For all of us that have had difficulty trueing, and balancing the Coker Firestone bias tires, this will be welcome improvment.

[Talkwrench]

Hey Danny hows things?

Brian. .I wish!

John, they are good ol' Firestone blackwalls. They had to put a fair few weights on the back tyres, but I would expect that when you see the amount of rubber there is.. I have had no previous problems with these tyres that's why I got them again. Zipped along the fwy doing 65 yesterday took my hands off the wheel , straight as..

[Bader]

I run 7.50 on a 28 model a phaeton,a 29 av8, 8ba, and a 40 deluxe fordor,they all pull those gears and tires just fine even the stock model a.

[Brian]

And...they fill those rear fenders nicely!

[Talkwrench]

Amen !
Just as a side note, I put the heavy sidewall rib on the inside. Some may not realise there is a heavy rib and a light one on the Firestones. I made sure I pointed this out to the guy fitting them 'cause sure as eggs he would have fu*(ed it up.