Wheels Wider In Front Than Back

[DaisyPusher]

I noticed the other day that the wheels in back are narrower than the wheels in front. I know I have a shortened Ford 8" in back, but is this common for everyone or is it just me? And does it have a major bearing on handling/cornering?

 

[Barry]

Can't comment on your narrowed Ford 8" rear axle.

Check the General Data section of the appropriate Work Shop Manual (WSM) and you will see that the rear track width for series Alpines is 2-1/2" narrower than the front track width.

FWIW, that was typical of British sports cars in the '50's and '60's to reduce rear roll stiffness and increase terminal understeer.

Just my opinion, YMMV.

 

[DaisyPusher]

Interesting; I was not aware of that. Just by eyeballing it, it looks like it's about that far off in back. Thank you very much, Barry!

 

[husky drvr]

Can't comment on your narrowed Ford 8" rear axle.

Check the General Data section of the appropriate Work Shop Manual (WSM) and you will see the the rear track width for series Alpines is 2-1/2" narrower than the front track width.

FWIW, that was typical of British sports cars in the '50's and '60's to reduce rear roll stiffness and increase terminal understeer.

Just my opinion, YMMV.

Barry,

Just another thought. I would say that Rootes was just being typical Rootes and using the same rear end housing and axles for all production as a cost saving opportunity. That is, there was no need to produce special length rear housings and axles just to accommodate Alpines sold with steel wheels. If you check WSM 124, when wire wheels are fitted, then the rear track measurement gains two inches while the front only gains 0.25 inch. This brings the front and rear track widths closer to equality, visually more nearly fills the wheel well, and is a function of the wire wheel hub and the way it mounts the wheel away from the steel wheel's mount surface.

The Alpine's rear wheel wells are more "generously" proportioned than other contemporary Rootes products. Guess I am just trying to say that the Alpine was designed and styled to have wire wheels, not steel wheels. This becomes more apparent when you also check the tread width dimensions for the Rapiers in the same WSM. Rapier III's with front drums have less than an inch difference, front and rear. Rapier IV's with front disks increased the front track measurement two inches while the rear remained unchanged. There is a bit of apples to oranges here because Alpines use Girling brake systems while the Rapier uses Lockheed brake systems. The Rapier IV also went to 4.5Jx13" inch wheels from the earlier Rapier's 4Jx15" wheels. Rapiers were never offered with wire wheels.

HTH and YMMV

 

[Toyanvil]

I never liked the look, so I am running 15x6 25mm off-set in the front and 15x7 20mm off-set in the rear.

 

[RevolverRob]

I'm almost positive Rootes engineers knew what they were doing re: track width.

Track width is inversely proportional to weight transference during cornering. Narrowing the rear track width, relative to the front, allows for several things.

1) Lighter IN/LB spring rates in the front
2) Increased straight line stability at higher speed
3) More predictive weight transfer when cornering
4) Induces oversteer more easily at low speeds or high-degree angle turns.

The lighter spring rates in the front dramatically improve comfort...Alpines with worn out suspension components ride worse than straight-axle dump trucks. The increased stability makes the car more comfortable and safer to drive longer distances. Of course, better predictive weight transfer, helps with driving in all situations. And if you don't appreciate oversteer at low-speeds when you turn the wheel and push the skinny pedal down...then I'm not sure why you'd want to own a sportscar of any stripe!

Fortunately, the weight distribution in the Alpine is fairly close to 50/50 and power output (at least non-engine swapped cars) is relatively low. Such that squaring off the track-width via running wider tires in the rear vs. front, doesn't make an appreciable negative difference in handling. The car is sufficiently well balanced and (under)powered that it is difficult to overwhelm modern summer tires let alone R-comps or slicks. Basically, you'll get pretty neutral handling with low-profile modern rubber.

 

[65beam]

wheels

Keep in mind that the Alpine is based on the Husky floor pan.

 

[DaisyPusher]

That makes sense. I pretty much noticed the width difference and blurted out a question before stopping and considering that it was designed that way. I'm used to working on DeLoreans all day where it's inverse. My car is also heavily modified with almost all new suspension. Just replaced the engine mounts and now there's basically no body roll or jumping when cornering/going over dips. Very predictable steering

 

[Jay Laifman]

FWIW, the wire wheeled Alpines had a wider rear track. I like the looks of it because the wheels don't look so sucked in. My assumption is that in this case, it was not a design, but a result of the hubs.

 

[DanR]

Sharpe cornering also comes into play!

Towing a trailer can be a good comparison.

Making a turn you are apt to have the rear come into contact with something the front cleared

I believe that was also engineered into the Rootes Alpine for racing. My 10 mills worth.

DanR

P.S. The debate shall go on, and on & on

 

[alpine_64]

I believe that was also engineered into the Rootes Alpine for racing. My 10 mills worth.

DanR

P.S. The debate shall go on, and on & on

Dan normally agree with you .. But not on this. Iirc there was a period peice where they explained the inset track. The thought was to make it safe for average drivers. The wider front narrow back means intial understeer into a corner with final oversteer...

so if you go into a corner to fast it starts to scrub speed and understeer.. You lift off and the back starts to come round and you recover the line. In otherwords lift off throttle to recover...use steering to correct Safer for lesser skill. If squared it would be more responsive on turn in but more likely to spin.

When they raced the cars they tended to square the track Front to rear which meant morr ultimate cornering speed but more skill required.

Then agian... Thats just memory of what i read and my .02 ;-)