Mumford Bar?

OZCOBRA · #1 (**permalink**) 05-11-2003, 04:16 AM

I'm wondering if anyone else but 750(Craig) knows what a MUMFORD BAR is ? As l've never heard of it ,related to rear suspensions. Any input would be great. Paul

mr bruce · #2 (**permalink**) 05-11-2003, 04:58 AM

Mummford link, basically a variation of the Watts link. I've seen very few. One had the centre rocker mounted on the chassis, and another had it mounted to the rear axle housing. One of the Super Seven MFGs uses a Mummford link on their cars.Side to side axle movement is slight in a cobra do to the limited rear suspension travel on a cobra so a panhard bar is usually the way to go.There is a variation that I saw once on a Super Modified Circle track car, that supposidly transfered weight from the outside rite rear tire ,to the left front. I have this particulare settup on one of my Daytona Coupes, when I get it running ,I'll let you know how it works.

OZCOBRA · #3 (**permalink**) 05-11-2003, 05:12 AM

Mr.Bruce, Thanks for the info ,i had thought it was some sort of watts link setup but wasn't sure,i'm running a 4 link rear but hadn't settled on a lateral stablizer (ie.watts or Panhard).Good luck with the coupes and please do let us know how that setup works.
regards Paul

Art Burtt · #4 (**permalink**) 05-11-2003, 06:39 AM

Nah it's a bar where chevy owners hang out they are mum on Fords!!

750hp · #5 (**permalink**) 05-13-2003, 06:00 AM

Paul,
It takes me a while, but I eventually find out when people mention my name

What I liked about the Mumford Bars was the ability to adjust the roll centre. Here's a photo of a sports racer (Mallock) with the Mumford. you can see the two outer 6061T6 bars coming together in a "V" shape. The point at which they would intersect is the roll centre.

I haven't yet adjusted my car to feel the difference, but it's something that i will be playing with over the next couple of months.

Here's the new Superformance Super 7 replica, also with the Mumford.....

OZCOBRA · #6 (**permalink**) 05-14-2003, 02:45 AM

Craig the pic's are great,is there much to setting it up and applying to the cobra ,your chasis i noticed you are running the the 4 link to the rear any chance of a photo of your application .Is there any particular reference material I could read ,as I am yet to find this setup anywhere, again thanks for the photos.
P.S. The car looks great, that hood is awesome ,I think Australia Post might well be interested, SPONSORSHIP Maybe????

Regards Paul

750hp · #7 (**permalink**) 05-14-2003, 07:59 AM

Paul,
AC Andy and Aussie Mike have been up to look at the car in the last week or so. It's about time you came up to Brisbane, isn't it?

I've attached a photo of my Mumford bars while the car was sitting in the paint shop. It's a shocking photo, but it's the only one that I could find.....

I'll get a hold of Ray Mallock's book that outlines all changes available, and the likely outcome of tweaking the rear suspension.

Steve R · #8 (**permalink**) 05-15-2003, 03:06 AM

Veddy Veddy interestink.

OZCOBRA · #9 (**permalink**) 05-15-2003, 05:08 AM

Craig,
The first chance i get i'll certainly be up there.

Was the setup simple to engineer with regards to positioning?

Ray Mallock's book is it widely available?Is along the lines of the Herb Adams chassis design book I found it easy to relate too.

Catchya soon Paul

750hp · #10 (**permalink**) 05-17-2003, 03:40 AM

Paul,
I only just noticed your latest post on here - sorry! The guy that decided that the Mumford would work best for my application is racing at Oran Park this weekend, but I'll get the Mallock book on Tuesday. This book isn't like Carroll Smith's books, rather it's a build manual for the Mallock line of sports racing cars. I'll scan the relevant info, and email it to you.

Hope you're doing OK,

Craig

OZCOBRA · #11 (**permalink**) 05-17-2003, 05:32 AM

Craig,
Thanks mate ,any info would be great back into it sunday.
Regards Paul

Tom Kirkham · #12 (**permalink**) 05-17-2003, 05:30 PM

I belive that Roush put a Mumford link on the Boss Mustang they built for Ford with an electronic fuel injected Boss 429 (that was closer to 500 cid).

I would also love to see what Mallock wrote about the Mumford link. Just before Ray Mallock died he wrote an article in Race Car Engineering about live rear axles. In it he discused the Mumford link, Watts link as well as the Panhard bar. I will see if I can find it.

750hp · #13 (**permalink**) 05-18-2003, 05:04 AM

Tom - you've reminded me about that article. Now I can't remember if it was Race Car Engineer or Racetech magazine.... both fantastic magazines that leave most other "car tech" magazines for dead!!! I'll also have a dig around to see what comes up. That Mustang was a bit of a weapon also, from memory it came about after GM started building a 600ish cube Camaro a few years back, didn't it?

Paul - the chassis and suspension were built before I had the fuel cell, swirl pot, pumps etc in place, so whatever space was required for the Mumford was used. It's not the most compact way of locating the diff, but it's not too bad. I found that I had a little too much rear body roll on the race track, so I'm hoping that I can change that by simply lowering the rear roll centre. I'll have to do some serious reading before I know with any confidence if this will throw anything else out of balance by doing this.

750hp · #14 (**permalink**) 05-20-2003, 09:55 PM

Tom - after much digging, I found the RACECAR Vol 3 No 5 magazine with the article by the late Major Arthur Mallock. As far as I'm aware, his son Ray is still alive and kicking.

I don't have a scanner nearby, but here's the majority of what was written about the Mumford system:

We have tried nine different systems of sideways axle location. The requirement is to provide a rollcentre which stays constant relative to the chassis with suspension travel.

In this respect, the popular, axle-mounted Watts Linkage is the worst. By mounting the Watt pivot on the chassis, the roll centre cannot move, because it has a bolt through it, and the rods do not move in roll. For clearance reasons, it is often convenient to mount the pivot left-of-centre. If the rod lengths and pivot ratios are changed in proportion, Watts geometry is still maintained. This is an excellent system when super-low rollcentres and ground clearance are not considerations. For a lower rollcentre, the system can be mounted horizontally.

For best compromise with "Stagecoach Effect" however, the rollcentre height should be about 3in - and for the optimum ground-effect, the whole mechanism must be mounted above the venturi.

This is where the Mumford axle location system comes into it's own. By carefully calculation the pivot lengths, the rollcentre movement can be kept to less than 0.1". As it is invisible, it can be set to any desired height (even below ground).

Michael Mumford's system offers the advantages of nil spurious vertical loads, and excellent rollcentre control. Very low rollcentres are practical, well below ground clearance, and thus the system offers excellent bump scrub. On bump, the ground clearance actually increases"

(Stagecoach effect is where one wheel hits a bump, and the whole axle moves sideways)

The Mallock book that I made mention of is actually Proprietary information owned by Mallock Sports Cars. It is basically made up of engineering drawings of their chassis and associated components with notes about specific measurements and advice on adjustments. Very interesting, but it'd be best for me to refrain from posting this info on the internet...

OZCOBRA · #15 (**permalink**) 06-08-2003, 03:12 AM

Craig,
How are you and that beast of a car going?Any more track time or testing since the last post

I've been lookig for that volume of race car mag. with no luck to date, is there a chance you may be able to copy the relevant info ie. the drawings and tech. data you mentioned in your post and sned it on down.
Or perhaps any other suggestions on where i may find it?
catchya soon Paul

750hp · #16 (**permalink**) 06-08-2003, 06:04 PM

Paul,
I'll get some photocopies for you. My car is registered now, and as soon as I fix a small problem with the exhaust, I'll take it for it's first drive on the street. That should be interesting.... I have the feeling that it's going to look a little out of place sitting at traffic lights with Hyundais, Toyota Echos and other mundane family cars around it!

Clois Harlan · #17 (**permalink**) 05-12-2006, 06:04 AM

Craig,

How have you and your Mumford bar set up faired over the last couple of years. I guess you have had enough time on the track to evaluate the pro's and con's of your Cobra's rear suspension.

I am considering a Mumford set up for my Cobra as well and would appreciate you posting any pictures you might have of your set up. Also, if you have any advise for the part sources I would appreciate that as well. Tall order I know but thanks in advance for your input.

Clois Harlan

superfred · #18 (**permalink**) 06-25-2006, 11:06 PM

Quote:

Originally Posted by 750hp

Tom - after much digging, I found the RACECAR Vol 3 No 5 magazine with the article by the late Major Arthur Mallock. As far as I'm aware, his son Ray is still alive and kicking.

I don't have a scanner nearby, but here's the majority of what was written about the Mumford system:

We have tried nine different systems of sideways axle location. The requirement is to provide a rollcentre which stays constant relative to the chassis with suspension travel.

In this respect, the popular, axle-mounted Watts Linkage is the worst. By mounting the Watt pivot on the chassis, the roll centre cannot move, because it has a bolt through it, and the rods do not move in roll. For clearance reasons, it is often convenient to mount the pivot left-of-centre. If the rod lengths and pivot ratios are changed in proportion, Watts geometry is still maintained. This is an excellent system when super-low rollcentres and ground clearance are not considerations. For a lower rollcentre, the system can be mounted horizontally.

For best compromise with "Stagecoach Effect" however, the rollcentre height should be about 3in - and for the optimum ground-effect, the whole mechanism must be mounted above the venturi.

This is where the Mumford axle location system comes into it's own. By carefully calculation the pivot lengths, the rollcentre movement can be kept to less than 0.1". As it is invisible, it can be set to any desired height (even below ground).

Michael Mumford's system offers the advantages of nil spurious vertical loads, and excellent rollcentre control. Very low rollcentres are practical, well below ground clearance, and thus the system offers excellent bump scrub. On bump, the ground clearance actually increases"

(Stagecoach effect is where one wheel hits a bump, and the whole axle moves sideways)

The Mallock book that I made mention of is actually Proprietary information owned by Mallock Sports Cars. It is basically made up of engineering drawings of their chassis and associated components with notes about specific measurements and advice on adjustments. Very interesting, but it'd be best for me to refrain from posting this info on the internet...

New bee here, Was hoping to get in touch with Craig to talk about an old post on the Mumford system. I'm shooting from the hip, but is there a way to get a email address for Craig? I haven't checked any FAQs yet, so pardon me.

Thanks, Fred

Rebel1 · #19 (**permalink**) 06-26-2006, 12:04 AM

Fred...send a PM from here.

Craig lives in Brisbane Australia and still gets on here occasionally.

A PM should get a response.

Cheers

hssss · #20 (**permalink**) 06-26-2006, 09:33 PM

If you would like I can send some pics and diagrams of Mumford link setups complete with angles. For some reason my album site dosn't like those pics.

I did a lot of research and it seems the best setup if using a solid rear axle is a 3 link, easily done using a late mustang 8.8, and a Mumford link