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Author Topic:   Solid Third Link in Comparison to a Locked 4 Link
jammin
Dirt Administrator

Total posts: 5060
posted August 28, 2002 06:24 PM UIN: 16262997
Guys, I drew up this little illustration to ask all of you, can you see a difference between a locked 4 link and a solid bar 3 link in these setups other than the rotation of the third link will actually lift more than a four? I think they will work virtually the same.

What do you think?

George Gilliland
Dirt Full Roller

Total posts: 39
posted August 28, 2002 07:28 PM
I think you are right about the overall reaction, but the locked four link reaction will be primarily delivered to one side. The three link will be split side to side as determined by the location of the third link.

jammin
Dirt Administrator

Total posts: 5060
posted August 28, 2002 08:21 PM UIN: 16262997
If the left side was locked, and then the right side was floated.....what then?

jammin

A2KY2K88
Dirt Forum Racer

Total posts: 77
posted August 29, 2002 12:59 AM
The locked 4 link will not work because it will bind and will not move up or down. You have to take the top bar off, which makes it a 2 link.

wfoondirt
Dirt Freak

Total posts: 242
posted August 29, 2002 09:46 AM
The geometry of the above drawings puts the instant center behind the rearend and below ground, thus making the rearend squat on accel.

2nd2none
Dirt Maniac

Total posts: 193
posted August 29, 2002 11:53 AM
Shouldnt the solid bar on the 3 link drawing be running downhill?

George Gilliland
Dirt Full Roller

Total posts: 39
posted August 30, 2002 02:09 PM
quote:
Originally posted by 2nd2none:
Shouldnt the solid bar on the 3 link drawing be running downhill?

Yes the top link should be inclined the other way.
Also note the the four link that is not locked has a linear diagonal motion. This motion is better than the arc type motion of the three link system. It does however take more parts.

jammin
Dirt Administrator

Total posts: 5060
posted August 31, 2002 08:12 PM UIN: 16262997
I thought that too George, but with the forward force on those links, It will act just as a locked 4 link and roll it under. I saw one in action....he he. Thats why I posted this pic. With a solid link on both and top, these two are very similar.

jammin

Pickles
Dirt Forum Racer

Total posts: 76
posted September 03, 2002 09:48 PM
Okay...please explain to this dummy what defines a "locked" 4 link. Jammin, ever think about adding a glossary of racing terminology.

jammin
Dirt Administrator

Total posts: 5060
posted September 04, 2002 05:50 AM UIN: 16262997
A locked 4 link is a birdcage on the left rear housing that is locked into place. It will not index(float) around the axle housing. That is a good idea on the terms.


jammin

Pickles
Dirt Forum Racer

Total posts: 76
posted September 04, 2002 11:29 PM
Thanks!

Pickles
Dirt Forum Racer

Total posts: 76
posted September 07, 2002 12:34 PM
Looking in the Speedway catalog, I see a floating birdcage with a sealed bearing. Obviously, not going to be able to put that on an assembled axle tube. So...how do you float a clamp on birdcage? Loosen the clamp so it will turn I assume. But then do you grease it? Add a piece of plastic between the tube and birdcage? Speedway said they do not have a plastic bearing for that purpose. ???

dirtracer14
Dirt Freak

Total posts: 333
posted September 07, 2002 12:38 PM UIN: 23443678
You can put the birdcage on a rear if you pull the hud and cut off the brake brackets, they will slide over the snout.

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