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MG MGB Technical - 6-inch x 15 dayton wire wheels

I have been contemplating replacing the 14 inch wire wheels with 15 inch. have visited all of the archives and found that 15 inch wire wheels will fit nicely on my 1963 B using 195/65x15 tires.

However, everyone seems to be stating to purchase dayton wheels rather than dunlop as they are made in india. Okay, but dayton wheels only come in six inch widths and I was planning on 5.5 maximum. to purchase 5.5 width today means that you buy dunlop. I have considered pannasprot centrelock wheels also but really don't care for the looks of all thaat chrome in the middle.

Does anyone have expereince with runnig dayton six inch wire wheels on their early model b. interested in perspective of tire clearance and what size tires. this seems like a little too much width for a stock suspenstion...

thanks
edward

Edward-
I use the Dayton wheels. To retain the original rolling radius and thus maintain speedometer accuracy, I mounted P195/60R15 tires. 5.5" is the absolute minimum rim width for some some tires in this size, and some 195-width tires require a minimum of 6" width rims. Whichever wheel you choose, you should make sure that your rear leaf spring bushings are in good shape or you'll have problems with the sidewalls of the wider tires rubbing on the lip inside the wheelwell. You might want to seriously consider mounting Doug Jackson's Panhard rod. Not only will your tires never rub, but the handling will be improved, especially when taking advantage of the better tires to corner hard.
Steve S.

thanks steve,

wwhere do I find out information about doug jackson's panhard rod

thanks
edward

Edward-
Click on this: http://www.mgbmga.com/
Steve S.

I run the Dunlop 15x5.5 72-spoke wheels on my '65 B. The only modification I did was installing Superflex bushings in the rear of the car. I replaced the leaf springs while I was at it. I have no problems with rubbing.

The 6" wheels are likely to be VERY heavy. I say this because my 5.5" wheels are already really heavy and 6" would only be moreso. I'm running 195/60R15 tires with no problems. A 6" rim would likely fit the tires a bit nicer but I'm not sure I would go that route personally. You can see pictures of my setup on my web site at http://www.twosims.com/ in the "Hobbies" section.
Steve Simmons

I am running 195 55 15 dunlop w-10 tires on 15x6 alloy wheels. The OD is about 5% less than stock, but the handling is far superior to stock and the ride equal or better. I converted from wire hubs to bolt hubs to be able to use alloy wheels. The offset is critical though to avoid rubbing. And when you really push it with larger sticky tires it will still rub in the rear on occasion. I am seriously considering installing a panhard rod.
Barry
Barry Parkinson

I believe the Dayton 457F is 5", and the 480 is 6". I have 72 spoke 15" 457F's on a '74 GT, and am awaiting a set for my '73 roadster. Got'em from British Wire Wheel. BWW has treated me fine+ through a couple of transactions -- I wouldn't think of shopping anywhere else for wires.

http://www.britishwirewheel.com/wheels.htm

BTW: I use Dunlop 195/65's on them with no rubs. (I felt compelled to mount Dunlops down there somewhere.)
Larry Bailey

As you fellows have added size and mass to these wheels and tires, how does that affect unsprung weight issues, such as shock requirements, and spring rates?? It may not be significant, but with steel rims, it could be and I would imagine that 195 55/60R 15 tires are heavier than the 185 70 R 14s on my GT. In my case I went to aluminum rims to offset the weight of the larger tires and OE steel rims. I am sure that folks looking to do as you guys have will want to know what you have done to compensate for any significant negatives you may have encountered, if any. Thanks!
Bob Muenchausen

Bob,

You're absolutely right about the unsprung weight. I immedeiately and definitely felt the difference.

For me anyway, that was offset by two things. The first was the stickiness. The old Michelin XZX's that I'd had on there were so dried out and worn that driving in the rain was an iffy proposition, and attempting to drive in even a light dusting of snow was insane. And, I had simply adapted to the understeer as the front end slid around every turn in my hilly and twisty region. Once the new tires/wheels were mounted, I had to completely change my driving style. Now now I can corner hard, even when the road is wet. I drive my MGs every day and don't race them or push them TOO hard (though sometimes I do have to keep a sharp look out for deer and fallen trees...), so adapting to the car's new handling characteristics has not been a big deal for me.

The other mitigating change was, though I'm loath to admit it, the appearance (I've never liked the Rostyles). The chrome wires look great on a GT. It seems to add to the car's inherent dignity.

Anyway, to directly answer your question: I haven't done anything to the car to compensate for the change in the weight of the wheels and tires, and, yes, the change was very apparent.

Thanks for asking the question, Bob. It's good to have that point made: if a person's values are akin to mine (as expressed long-windedly above), then the 195/65's on 15" 72-spoke wheels will be welcomed. Otherwise, you could end up having spent nearly $1500 on something you truly hate.

(hmm.... I hadn't really thought about the shock requirements... There seem to be a bunch of Mech Engrs here. Anyone care to comment?)
Larry Bailey

I went from stock wheels with 185/70R14 to 15x5.5x72S with 195/60R15. THe weight of the tires was nearly identical but the wheels themselves are MUCH heavier than the originals. I've probably added 15 pounds of unsprung weight.

The performance difference isn't easy to determine. The tires, being lower profile and wider do handle much better than the ones I previously used. Steering is only slightly heavier at lower speeds. At high speeds the car rides smoother despite the heavier wheels and I attribute this to the wider and higher quality tires.

As for handling, it's a bit difficult to compare since my old tires were, well... old! It isn't fair to compare them to new tires of any kind but from what I remember of them when new they didn't handle as nicely as my new setup.

With the old tires and wheels the car was more susceptible to over/understeer changes in hard canyon driving, especially in rough corners. Having more tire on the road seems to be what helps the most. I haven't really noticed any negative effects of the heavier wheels on the suspension and it's reactions to the road surface. THe car handles more neutral and sticky than ever. The only negative effect I've found so far is that the car has more body roll now due to the added traction. I have yet to try a stiffer sway bar.

BTW, my car is a '65 Roadster with stock suspension and Poly Bushings all around.
Steve Simmons

I've heard a lot of talk that getting the right backspacing/off-set is critical. What is a good backspacing/off-set for 15" x 6" wheels. I'm planning on using 195/60/15 tires.


thank you

Chad Ellars
Chad Ellars

Comparing the weight of new tires vs old, I found the old p165x14 radials to be noticably lighter than the 195 55 15 tires, however by going to alloy wheels instead of stock wire wheels the overall weight was about a pound less with the new combo. My experience with the change in handling with a 67gt would mirror the description by Steve Simmons of his 65 roadster. I would add though that I'm going to install fiero seats. I'm afraid I'm going to bend the steering wheel on those left hand turns with no lateral support. I didn't notice the lack of lateral support that much before the tire and wheel change.
Modernly the choice of tires is also extremely important. My new gm coupe has 16x6 wheels 225x50 tires. The car handles beautifully and is balanced nicely etc. I changed the factory tires for a set of super hi performance tires (same size) with sticky (rain & dry)tread compound and wow! the car feels like it is glued to the road. Again the bucket seats are inadequate. The car is front wheel drive and was nicely balanced with ultimate understeer. Originally I left the orig rear tires on and changed the front tires only. I figured with the light rear end the tires were way oversized and more than adequate. Whoops! I suddenly had a tail happy car. So far I've tried Goodyear KDW, and Yokohama a520. The Yokohama's ride hard and are very noisy and wear fast but stick well wet or dry. The KDW's are better all around. The Dunlops work real well on the GT but I haven't compared other tires since I've gone to 15' wheels.
Barry
Barry Parkinson

Thanks for the detailed and thoughtful answers!
Bob Muenchausen

Chad,

I've just installed 15x6 panasports with a 22mm off-set wearing Yokohama Avid H4 tires. Han't had any problems yet. The off-set is what both my tire guy and panasport recomended.

These replaced the standard 4" disc rims with 20 year old 165/14 tires, so comparing the handling will be like comparing apples and oranges. Lets just say it feels like a completly different car.

Tim.
Tim Boyle

This thread was discussed between 28/06/2003 and 03/07/2003

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