14 replies to this topic

[HUBBA.HUBBA]

I need some adjustible tie bars on my hummer mini project. Was thinking I could just use/transfe the existing adjustable heavy duty ones off the mini and then treating it to some nice rose jointed ones. But wasn't sure what the advantage was .... crisper suspension movement?

[nicklouse]

on a race car you have better control or the suspension, not really worth them on anything else.

[Cooperman]

Definitely not for a road or rally car where some suspension compliance is necessary.

[Spider]

They will help hold the suspension more accurately, but without the same on the lower arms, it's only half baked. It will make the ride 'more noisy' and in some countries (like ours) not legal for road use.

 

Stick with rubber.

[HUBBA.HUBBA]

They will help hold the suspension more accurately, but without the same on the lower arms, it's only half baked. It will make the ride 'more noisy' and in some countries (like ours) not legal for road use.
 
Stick with rubber.

I've already rose jointed adjustible bottom arms and my mini is mainly for track days

[Spider]

 

They will help hold the suspension more accurately, but without the same on the lower arms, it's only half baked. It will make the ride 'more noisy' and in some countries (like ours) not legal for road use.
 
Stick with rubber.

I've already rose jointed adjustible bottom arms and my mini is mainly for track days

 

 

In that case, go for Rose Jointed Tie Bars. They will help the car drive straighter and more so, feel much better / predictable under brakes.

 

Mind you, you'll only get the benefits from these if you have tyres to 'match'.

[nicklouse]

i would look at some Boots for the joints or they will  not last.

[tiger99]

I suggest NOT using the utterly amateurish design that is on the market, which puts the pivot centre in the wrong place and causes castor change on bump and other maladies. It also may impose inappropriate lateral loads on the rose joint under certain conditions.

To do it PROPERLY,the mounting ears for the tie bars need to come off and new brackets, stronger than the originals (rigid pivots vastly increase the impact loads), need to be made to put the rose joint centres exactly where the rubber bush centres were, which, funnily enough, is the correct place. Alec knew what he was doing!.

I am astonished that none of the usual suppliers have seen the problems with the stuff that they sell.

Ideally you would still have a small but tightly controlled amount of compliance at both the lower arm and tie bar pivots to make the car more tolerable on the road, and it should not be beyond the wit of man to devise an assembly with stiff rubber bushes to isolate the rose joints.

[mini13]

hmmmmm,

 

how much effect does this really have?  just thinking in the air... std tie rod is 14 1/4" apparently, without measuring it I guess we lose an inch or so going to rosejoints. tie rod to kingpin line angle "should be close to 90 degree ish"  that tells me that the castor is going to move about sod all.

 

I cant think of any other results of shortening the tie bar at the moment,

 

and Yes always reinforce the tie bar mount with urated bushes or RJ's

[mini13]

just had a look and asuming one inch difference in length, over 3" of suspension travel that will make the bottom ball loint move forward approx an extra ten thou...

[HUBBA.HUBBA]

i would look at some Boots for the joints or they will  not last.

Good idea. I have one on my KAD internal gear lever linkage. Think I got it from RS components

[Ethel]

You'll need boots if you need an MoT too.

[mini13]

also if you are MOTing it is wise to stuff a load of grease in the boot,

 

there is normally a tiny bit of play in a rose joint, and the grease will help discuise this to the MOT guy dosent bobble the wheel hear a clonk and tell you the buishes are shot ( a good MOT guy should be fine, but they arnt always, also Ive heard of scruitineers pulling up RJ's for play too even when they are new).

[tiger99]

Apparently you only need boots if there were boots originally. That of course applies directly to cars that were rose jointed from new. There does not seem to be anything to help the tester to decide what to do if it is a modification.

There are certain people on another inferior forum who get quite adamant about their right to not fit boots.

In my opinion you would be daft to not fit them, regardless of the MOT. None of us want stuff wearing out prematurely. You may even want to use rose joints with in-built grease nipples, but please do check the static strength and fatigue ratings carefully as, depending where the nipple is fitted, there is a significant structural effect. The manufacturers catalogues should explain all, but some brands of rod end are markedly inferior to others.

[mini13]

yeah, always use a decent brand, they are not really that expensive, and they do last well as long as you keep the crap put of them.