Suzuki Club UK

I am unfamiliar with a leaf spring setup and am asking how obvious it is when they are worn and need replaced.

Also, how much lift would roughly be gained from having 100mm shackles and what kind of effect does such a modification have on the ride quality under road use?

Hiya.

If your springs are completely flat or inverted/bowed the wrong way, then they're in trouble.

Sometimes if you take the weight off them for a few days by jacking up your suzi and putting it on axle stands under the chassis rails (so the axles hang without having any weight on them) you can get springs to temporarily settle back into place,but it's really just a cheat that won't last long (if it works at all).

Longer shackles can screw up your steering geometry, the longer they are the harder it is to turn the wheel. I had long shackles years ago, with bigger tyres, and I couldn't park. Couldn't turn the wheel. I'm not peewee herman either - 6' 2" regular gym attendee.

I think my shackles were longer than 100mm though.

100mm should give roughly 50mm lift if you do it,but its not a great idea.

Stock shackles are 70mm long so if you run 100mm shackles there will be 15mm lift, not much at all and not enough to really effect your caster angle.

Oops, I assumed that we were talking about 100mm longer than standard(170mm total), rather than 100mm overall... Silly me! Doh!

Had a feeling that was the case

My fronts are almost level but not quite but the rears are okay. No worries for now I guess.

Longer shackles I guess would put extra strain on the springs? Would it also increase bounce?

I have +15mm shackles on the front with 2" lift springs and they seem fine.... however I have +3" shackles on the back and they are awful.
The shackles have changed the angle the springs sit at by quite a lot, so now when the rear goes over bumps, the axle is going up and back instead of mostly straight up
It makes it very uncomfortable on the back, as I think the springs are pushing against the bumps rather than going up over them... if you see what I mean

So I figured, since I'm not busy at work, I'd make some longer shackles and just try them out at the weekend
Seems like the way to go for now.

Has anyone ever tried fitting a second shock absorber? Would such a change need the IVA inspection?

Longer shackles usually steepen the shackle angle thus slightly increasing the spring rate, make sure that your shackle never sits vertically or past vertically as this will give the most resistance to compression.

If longer shackles are fitted the bumpstop height should be lowered to match so that that you don't over flex your springs.

Fitting a second set of shocks would make the ride really stiff and uncomfortable. Most aftermarket shocks are too stiff for light SJs as it is so two sets of shocks would be horrible.

Currently my shackles sit at about 45 degrees and I'm expecting it to go to around 70.