[gman74]

Hi just wondering when fitting a Jimnybits 75mm lift, do you need to extend your bumpstops?

[zukenutter]

What size tyres? Otherwise I say no. I've never extended bumpstops on either of my Jimnys or any of my Sierras. Plenty here will disagree though.

[gman74]

I have 215/75/15.

[zukenutter]

Then I wouldn't worry about them.

[gman74]

Cheers.

[Gwagensteve]

I might have the wrong end of the stick here, but I don't think tyre size is relevant - I reckon it's all about the compressed length of the supplied shocks. If the supplied shocks are greater than about 1" longer compressed than the stock shocks, then bumpstop spacing is required to be safe.

Steve.

[atari4x4]

Gwagensteve wrote:

I might have the wrong end of the stick here, but I don't think tyre size is relevant - I reckon it's all about the compressed length of the supplied shocks. If the supplied shocks are greater than about 1" longer compressed than the stock shocks, then bumpstop spacing is required to be safe.

Steve.

+1 to that logic...

[zukenutter]

Yeah that is a fair point. I buy my shocks based on lengths, not by what comes with a kit.

[GeckoXL7]

Im looking into bump stops at the moment to protect the shocks from bottoming out.

Instead of buying spacers/extensions im looking at universal DayStar/energy suspension extended bump stops which are 5" long but can cut them to size, they are made from polly and meant to stop the harsh thud if you manage to compress the springs enough to hit the bump stop. Delivery wise will work out cheaper for 4 of them delivered than two extensions delivered, cost $13 for a pair and around $46 for priority delivery from the US. People in aus are asking min $109 for a set of two then another 20 or so for delivery..

[atari4x4]

There is a vit/gv DIY bumpstop thread in good tech.

[Gwagensteve]

Gecko, you'll need to be very careful with using urethane bumpstops. Whilst they may offer a nice soft initial hit, it can be very hard to work out where the "hard bottom" point on them is.

I ran some urethane bumpstops from a holden Combo van in the rear of my car for a while, but I found I was still having problems with over compression. For an experiment, I put them in the vice and squashed them up. They squished from 120mm down to 35mm... and would have kept squishing. That's hard to engineer around, so I swapped to vitara bumpstops on welded in spacers.

I'd suggest you'd still want a rubber "hard stop" if you are using these bumpstops, or basically set your shock length based on metal to metal and then install the bumpstop.

Steve.

[sideways]

Gwagensteve wrote:

Gecko, you'll need to be very careful with using urethane bumpstops. Whilst they may offer a nice soft initial hit, it can be very hard to work out where the "hard bottom" point on them is.

I ran some urethane bumpstops from a holden Combo van in the rear of my car for a while, but I found I was still having problems with over compression. For an experiment, I put them in the vice and squashed them up. They squished from 120mm down to 35mm... and would have kept squishing. That's hard to engineer around, so I swapped to vitara bumpstops on welded in spacers.

I'd suggest you'd still want a rubber "hard stop" if you are using these bumpstops, or basically set your shock length based on metal to metal and then install the bumpstop.

Steve.

I've done the same with my St141 Corona wagon bump stops. They're rubber obviously.



Compressed they were 55-60mm. You could compress them about 1cm by hand.

I've had them in the front of my Sierra for ages and they fulfil their function of fitting the 30s, I can't say there's any difference in ride but I literally had no bumpstops before fitting these.

[Gwagensteve]

Stock Sierra front bumpstops aquish to about 25mm though, so what you've done is sound.

Removing a vitara bumpstop that squishes to 25mm, and rather than fitting that with a spacer, replacing it with a urethane bumpstop that squishes an unknown amount so you can fit longer shocks is a bit dicey.

Steve.

[atari4x4]

Gwagensteve wrote:

replacing it with a urethane bumpstop that squishes an unknown amount so you can fit longer shocks is a bit dicey.

Steve.

have you seen GeckoXL7's build thread... it's full of dicey.

[GeckoXL7]

Dicey is my middle name... I've got the bump stops comming there not the progressive type. And you can't cut.bellow a certain point.. if to soft I won't install them.