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satchell link
Posted: August 13, 2007, 8:22 pm
by sorta_se7en
Has anyone here looked at the Satchell link setup? It looks to be a good option for my (future) build, which will be street-only. Any advice or direction will be appreciated!
Posted: August 29, 2007, 10:05 am
by sorta_se7en
Wow. 140 views and not one lousy comment? I thought that with all the wise guys-er, smart folks on this forum that there'd be someone with an opinion on this setup. Well, if you're not going to help me, I'll just discuss it amongst myself.
Q. What's a Satchell Link suspension?
A. It's a variation on the 4-link, but with the lower links angled inward and
upward from the axle to the chassis.
Q. What's the advantage of this?
A. It locates the axle laterally without the need for a
panhard/watts/whatever
link (aka 'possum spreader, in these here parts).
Also, it supposedly gives antisquat PLUS good roll-steer characteristics.
Q. Whaddya mean "supposedly"? Herb says......
A. Yeah, Herb says. Do the geometry. A downsloping (frame-to-axle)lower
link means the drooping (inside) wheel always moves forward, the
other moves back, steering the axle to the outside of the curve. This is
OVERsteer, not understeer.
Q. Well, are there any other negatives with the Satchell?
A. Several. It's gonna be noisy, as it needs hard mounts rather than
rubber bushings. But in a Se7en, who would notice? The short links that
will fit under a Se7en are not optimal for performance. Also, in any
nonparallel-link setup, there are always twisting forces on the axle in a
turn.
Q. So, that explains them broke brackets and cracked tubes!
A. Maybe
Q. So why would anyone use the Satchell in a Locost?
A. Well, it's locost. It's simple (some will consider that a negative). And for
a street car it's probably perfectly adequate.
Q. So you're going to use the Satchell link in your build?
A. That's a definite maybe. I still like the idea of irs using CTS/Solstice
parts.
Now, that aughta pi** someone off and get a comment!

Posted: August 29, 2007, 10:09 am
by Titus
I thought you were trying to set up a link to Satchel Paige in the afterlife.

Posted: August 29, 2007, 10:56 am
by chetcpo
So why bother when a four link with a panhard would work at least as well and be much easier to set up?
Posted: August 29, 2007, 1:00 pm
by mookie
Well, I saw this post before but I thought it was something to do with a hook for the wife to hang her purse while she rides in the car.....
Posted: August 30, 2007, 5:59 pm
by sorta_se7en
Titus- heh.

"Don't look back. Something might be gaining on you."
Mookie- can't let the wife take her purse- I'd have to stop at every shop in sight!
Chetcpo- "So why bother..."
Well, a 4-link without a panhard seems simpler than a 4-link with one. As to setting up, I know little about suspensions; enlighten me as to what you mean. I'm just looking for a street setup that will work reasonably well, without a lot of twiddling.
Posted: August 30, 2007, 7:15 pm
by chetcpo
To be clearer, my only point is, that four link Locosts are the norm and there are good plans out there to guide you through it. Why bother blazing your own trail through the woods when there is one already beat out for you?
Posted: August 30, 2007, 7:55 pm
by jdgar0649
I thought about a Satchel link when I first started thinking I might build a Locost for just about all the same reasons.
BUT, several things stopped me.
1) the partial build that I was lucky enough to stumble upon was already set up for panhard rod.
2)The placement of a Satchel link puts the ends of the lower angled links right in a weaker portion of the frame (I think) connecting to tube B1 and close to the transmission tunnel (which on many cars seems to be left open at the bottom rear end.)
3) with the Locost it seems that the space is so limited between the rear axle and the frame that the Satchel link is impractical.
If I am wrong on any of this, someone please correct me.
Don't get me wrong, I thought it was a great idea, until I started to figure out how much longer it might take me to get the car on the road in order to figure it all out......at my age that is IMPORTANT! Although I am not to the age of not buying green bananas yet!
JOE
Posted: August 30, 2007, 9:33 pm
by sorta_se7en
Chetcpo- excellent point. Trouble is, I designed machinery for 30 years, and I just can't help myself! It's a compulsion.
jdgaro649- thanks, Joe-exactly the kind of comment I was hoping for. While my build will be locost in spirit only (see avatar) and the frame can be designed for the loads, space is prolly the critical factor- don't want the wb to exceed 96".
And the age thing- I resemble that remark!!!

Posted: August 30, 2007, 10:37 pm
by erturbo
Are those batteries under that there hood? What gives?
And yeah, i agree with Joe, you'd be hard pressed to fit all of that in the "boot."
Posted: August 30, 2007, 11:45 pm
by jdgar0649
Are those batteries under that there hood? What gives?
I noticed those odd block shapes myself and initially came to the same conclusion....until I realized they had to be some sort of graphic representation of 5 R1's linked together with some sophisticated drive train!
Right?
Joe
satchell link
Posted: August 30, 2007, 11:58 pm
by dannyw
I am also thinking about using this type of rear suspension on my (still on paper) MGB based special. My understanding of the Satchell link is that it does not require that the links are in any particular relationship to the ground, i.e., that the angled links could be angled up, down or be parallel with the ground. I also don't believe that you are stuck with rod ends in any type of suspension. Millions of cars are out there running everyday without them.
For what it's worth, my Bugeye Sprite has a four bar rear with coil-overs, all with rod ends, and it is not that rough. I suppose that rough on a Bugeye is relative, though...lol
I am also using taller tires than are common today, so that can also be taken into consideration.
The Bugeye has a lower link set-up more like some Lotus 7s, with the bars converging under the diff, rather than converging on the frame like the Satchell. I would change it on the Sprite, but there is very little of substance at that point to work with. In my case, my lower links angle down to the frame at ride height, and give me a lot of problems under acceleration, as well as a bigger issue with "lift" when you get off the throttle. Not much fun when you are trying to corner at speed. In autocross, I have yet to break traction with the inside tire in sharp corners
even without LSD. That was the intent, to gain more compliance than the Sprite had. Understeer can be overcome with throttle and the weber carbed Toyota 2TC under the hood.
My paper project is to build a 50's period style MGB based tube framed sportscar. If Ken Miles rings a bell, look at his R1 for one of my inspirations.
Using the MGB rear axle, I think that the satchell link is ideal, with longer lower links possible than I could get away with otherwise. The satchell link was first used on the Datsun 260 or 280 Z SCCA cars that Newman drove. Don't think they would put up with roll induced oversteer.
A problem on some cars (my Sprite) was there was no place for a panhard rod to go (don't forget that the axle end has to be able to move up and down as much as the axle does) and it would have cut the exhaust pipe path. Locosts tend to have side exhausts, so they can get away with that.
Another link system to look at, (and try to understand) is the Mallock WOBLINK. Or see what the Sprinters and Midget folks have used for years and years, called a Scotch yoke (not by them, though) not sure what they call them. It is a single sided three or four element link side control.....not unlike the WOBLINK.
Sorry to ramble so much, but I am surprised that more use has not been made of the satchell link.
Dan Wilson, Colorado Springs, CO
Posted: August 31, 2007, 12:30 am
by jdgar0649
I knew there was a thread on the UK site. Notice the name of one of the posters....Mr. Satchel gives a pretty nice acounting of his ideas.
http://www.locostbuilders.co.uk/viewthread.php?tid=2436
Hope this is helpful.
Joe
Posted: August 31, 2007, 3:20 am
by locostv8
A sort of Satchell link in a limited space is one of the main problems with the Fox Mustang. The problems are major binding and wheel lift on hard acceleration. For the solid axle car I am using a 3 link with probably a panhard bar or wats linkage.
Posted: August 31, 2007, 4:12 am
by mr.peabody.d
Sorry to ask bit any pictures of a Satchell link?