Mumford Linkage

the JoKeR · Post by **the JoKeR** » August 26, 2005, 2:13 pm

Has anybody got any good diagrams/dimensions for creating a Mumford Link rear suspension? Along those same lines, can anybody tell me why I wouldn't want to go with a Mumford Link compared to the standard panhard for a live rear axle? It's not much more work to fabricate, so if it's worth the effort.......

Plus, it looks much cooler!

the JoKeR · Post by **the JoKeR** » August 26, 2005, 11:25 pm

Here's a little extra info I came up with on the Mumford Link. Seems that any info out there, such as plans to build this link setup, are hidden pretty well!

The following link has a very good diagram of the link, but no dimensions, etc. Fun part is trying to figure out how it works after you look at it for the first time! :cool:

http://not2fast.com/chassis/mumford.shtml

Post by **chetcpo** » August 26, 2005, 11:59 pm

I looked at that link and then went and looked in my book, chassis engineering by Herb Adams and found nothing. I read about the Watt's linkage and then looked at the pics again. I still don't get it.

Edit:

Dug out my book "competition car suspension" by Allan Stanforth and found only one reference to "Mumford" and I'm not even sure it's the same guy.

One other approach to roll, currently under serious development for the car industry, is invento Mike Mumford's answer to the question, "What does a car really need?" Given the answer, "Better ride, less roll", computer/hydraulic control of an otherwise orthodox tube or bar is a solution if it can be produced simply and cheaply enough.

I just read a review of this book on Amazon that ironically said:

For example, while this book had descriptions of solid rear axle suspension types (the same ones covered in his previous book,) it left out the "Mumford link" suspension. Surely the newer book should have described the most recent suspension, but it isn't to be found. I guess there's only so much to automotive suspension design, yet I assumed the new book would have "new" information, necessitating it's publication. I just don't see it

No answers there either. A Google search revealed that Michael A. mumford applied for a patent for a "anti-roll" suspension in 12/04, but that could be something different.

Well, after staring at it for a while (I made it smaller so I could see it better :wink:

) I think I at least have a vague understanding of how it works. It looks very enticing to me. If I go live axle I may have to try it. Nice find!

CR_Turboguy · Post by **CR_Turboguy** » August 27, 2005, 8:55 am

Hmm.. that looks really familiar. I think Del is doing that in his race car. I'll be seeing it later today, I'll try to have a look/ask him more about it.

--JOsh

the JoKeR · Post by **the JoKeR** » August 27, 2005, 9:10 am

Maybe the reason I want to build it is because it doesn't look like it should work!

If I can't find actual build details, I'll probably make a scale model to test linkage distances before building. It seems odd how having the two "bellcrank" type pieces bolted to the frame will still allow up/down travel and full left/right roll capability of the axle while keeping it centered in the chassis. Obviously a 4-link set-up is still needed to keep the front/back movement in check.

CR_Turboguy · Post by **CR_Turboguy** » August 27, 2005, 7:15 pm

Well, at our test event today, I took a look & talked to Del, he's not using a Mumford, but a Watts. Thought it looked close though. Sorry I couldn't shed more light on it.

--JOsh

RebelGT · Post by **RebelGT** » October 4, 2005, 11:45 am

saw this, thought you might be interested.

http://www.tperformance.com/street_rod_ ... nkage_kit/

ostdi · Post by **ostdi** » October 4, 2005, 10:18 pm

Take a look at this guy's site, he is using a Mumford Link

http://texaslocost.homestead.com/Suspension.html

mr.peabody.d · Post by **mr.peabody.d** » October 5, 2005, 2:52 am

[Homer Simpson Voice]
MUMFORD......Hmmmmmmmmmmmmmm
[/Homer Simpson Voice]

dale · Post by **dale** » October 9, 2005, 11:54 am

I have also been trying to find info on the design specs for mumford as I want to lower the roll center of the live axle on mine to be closer to the ground level roll center of the front.
My understanding is that it is the only live axle setup that the roll center is adjustable.

Dale

SkinnyG · Post by **SkinnyG** » October 9, 2005, 12:09 pm

You can make a panhard height adjustable. The rear RC is where the panhard crosses the midline of the chassis. I mounted mine below the rear of the chassis for a RC of 4" in the rear. I think I'm the only one on the face of the earth who has done this.

I did some serious consideration of using a Mumford and then decided the Panhard was easier and cheaper. It doesn't look like the angles are critcal at all. Make sure the pivots have lever ratios that are the same, make sure the centrelink doesn't go over-centre, and try to keep the long arms long. It will likely also be easier to adapt one if the rear of your frame has not been built yet, so you can locate and strengthen the mounts effectively.

G

toyokogyo12aturbo · Post by **toyokogyo12aturbo** » December 21, 2005, 9:36 pm

SkinnyG wrote:I mounted mine below the rear of the chassis for a RC of 4" in the rear. I think I'm the only one on the face of the earth who has done this.

It doesn't look like the angles are critcal at all.

Click here (~2Mb) Check out the silver link in the rear. There's at least two of us.
This was a quik'n dirty panhard rod. I hope the angles your speaking of are on the Mumford linkage. A Panhard rod should be near horiz, from my understanging, to minimize lateral movement. Mine is not, it was a last minute addition. I'm going to redo it, probably with a chassis mouted Watt's link. I've wanted to do a Mumford from the begining but I lack info/time, and my dad already know everything about chassis mounted Watt's links.

SkinnyG · Post by **SkinnyG** » December 21, 2005, 10:06 pm

toyokogyo12aturbo wrote:I hope the angles your speaking of are on the Mumford linkage.

They is. AS long as it's reasonably semetrical, it should be fine. The centre rod ends I would mount such that they share symetrical points. If that makes sense.

How's the oversteer with a low panhard??

G

CR_Turboguy · Post by **CR_Turboguy** » January 6, 2006, 7:39 pm

Just ran across this today:

--JOsh

R1 Seven · Post by **R1 Seven** » January 18, 2006, 10:41 pm

Hey guys,

First post here...might as well start somewhere. I designed and built a mumford linkage for my car. There was a little bit of buzz about them in the Locost community a few years ago. But since there was (is) not a lot of info about them out there, I think most everyone steered away from them. I decided to go for it and it seemed to work out just fine. It gets my roll center pretty low in the rear at about 4" above the ground.

The picture in the previous post is from the Superformance S1. They put a mumford linkage in that car and ran it with an open diff. I talked with a dealer at a local autocross where I got to see one of those cars run. He had no wheel spin, even with the open diff.

Here is a picture of my setup:

LocostUSA.com

Mumford Linkage

Mumford Linkage

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