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Does anyone have the length of the Wheelers Superbumps? I'm trying to decide between the Superbumps or Timbren.


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After a recent trip to the dunes I discovered that my new tires rub the tops of the fender arches under full compression. I am running 305/70/17 MTR's which measure out at exactly 34". I also have a 3" lift and aggressive body mount chop. I am in the process of trying to remedy this issue and picked up a set of Wheeler's superbumps and both 1/4" and 3/8" spacers. I also have a 1/2" bandi body lift on the way.

Prior to installing the superbumps I thought it would make sense to take some measurements against the stock bump stops. The results were a little surprising. I used my hydraulic press and digital caliper to measure the compressed height at various levels of applied load. Not surprisingly the stock bump stops are very stiff and compress very little, while the superbumps have a more linear initial compression, thus the more desirable bottoming characteristics. The issue that is immediately apparent is that the Superbumps just keep compressing far past the stock fully compressed height. Up to 15mm at higher loads, which would correspond to a tremendous amount of additional up-travel at the wheel. Obviously it is difficult to do a real comparison without knowing the actual loads present at the bump stops, but given that the Wheeler's bumpstops intersect the stock compression curve at only 1400 lbs, it is safe to say they will allow significantly more up-travel than the stock bump stops. These tests were performed at around 75F and would probably be even more extreme at higher temperatures.

I also plotted the effect of the 1/4" and 3/8" spacers under the superbump, which extends the point of intersection with the stock bumpstop to 2600 lbs and 3800 lbs respectively. Since I am already hitting the wheel well with the stock bump stop, it would seem that the 3/8" spacer will be my best option. Any more spacer than that and the bump stop would likely be in continuous contact with the control arm. Hmm. I would like to have seen the Wheeler's bump stop provide the intial linear compression region and then quickly stiffen up to the point of matching the stock bumpstop at higher load levels. The 3/8" spacer might just do the trick though. Anyway, thought I would share.

:cheers:
There have been several reports from Australia that the superbumps have caused strut failures through overcompression.
fjcc.com.au

Basically, the consensus there is to avoid them like the plague. That's why I went with Timbren bumpstops. I still kiss the fender liner occasionally, but it's nothing like it was previously. If I hammered the pinch weld and added a 0.5" Bani body spacer, I think I'd get rid of it almost completely. I could adjust the front lift a little as well, as I still have a bit of a rake even with my offroad gear in the back and 160 litres of fuel onboard.
 

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I have the Superbumps and bottomed out pretty good through some big whoops/jumps a few weeks ago. I already have the 1/4" and 3/8" spacers, just hadn't installed them yet. I still think the Superbumps are a good investment, as has been mentioned they may have changed to a harder compound a few years ago and the failures in AU were with the original softer compound. Can also add their shim spacers if needed. I always heard the Timbrens, or at least the rear ones, were way too stiff and engaged too soon.

FYI Wheeler now makes rear Superbumps. Their wedsite claims they stop axle travel at the same spot as the stock bumps, but they also look to be able to accept spacers between the bump and the bracket if needed.
 

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Yeah I believe any aftermarket shocks (not spacer lifts) should be fine even when rubbing 34s and 35s at compression. My assumption is aftermarket coil-over uptravel is the same or better than the stock setup, which means no rubbing with stock 32" tires. But adding 1"-1.5" extra sidewall means you'll rub the fenders even though your shocks have not reached their limit. Not to saw people haven't damaged shocks due to too much uptravel, but in general just because our oversized tires are rubbing doesn't mean we've reached the limit of the shocks.
 

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Using spacers to make the bump stops the actual travel limiter is essential.

Wheelers without spacers could top out coil overs or tear into the fender well in a very violent way.

Like everything, know your limits... and your safe word.
 

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Using spacers to make the bump stops the actual travel limiter is essential.

Wheelers without spacers could top out coil overs or tear into the fender well in a very violent way.

Like everything, know your limits... and your safe word.
My safe word begins with fuuuuuuuuuu and ends with ck! , But by then it's usually too late and I've ripped my fender liners a bit more...
 
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