6112's at 19 with Coachbuilder .5" shim

Good evening all,

I originally installed CB .5" shims to my stock Bilsteins and gained mediocre lift. It was supposed to be 1" but was more like 3/4 inch or so.

I recently installed 6112's at 1.9" and it looks good (and rides great) but when its time for another set of tires I may want to step up and go with 295's.

Truck is a daily driver for work. I tow my travel trailer around 6x's a year (21' about 4k)

A few questions:

I still have the CB shims. I installed the 6112's originally as I have a hoist in my pole barn (doesnt everyone...) so removing and installing the shims is fairly easy. This would net me around 2.7"'s of lift give or take.

Removing and disassembling takes way more effort as I would need to take them to a shop to adjust up one perch to the 2.5" setting. I have spring compressors but its the chinzy type for Honda's and not comfortable messing with these and taking my head off.

Bottom line, Is there gonna be much of a difference in ride quality if I leave the 6112's at their current setting and install the shims? I know shims are frowned upon.

Inchitis sucks!

If I go this route I would likely go with the Icon add a leaf setup and 5160's for the rear.

Thanks!

 

Actually lots of people install the 6112 at 1.9 and add the CB shim to compensate for the lean or added lift. Some say it rides better at 1.9 setting. I have mine at top 2.5" setting and it rides good, no complaints. There is a whole thread about the bilstein 6112 in the suspension forum, lots of info.

 

I had 6112s at the 1.9” setting and 1 shim on the passenger side and 2 on the driver side. It raised it a little and I didn’t notice any worse handling or ride quality.

 

6112@1.9", 1/2" shim left side, 1/4" right. 5160 w/Icon AAL in the rear. Unloaded, I have about 1/4" rake (DB cover, 8" tool tray full of junk)
I have been thinking about swapping out the rear leaf pack for more rake or adding a 1" shackle.

 

295 is the width of a tire. That tells us nothing about what size tire you may want to run. I’m running a 295/55/20 on a 9” +20 wheel at 1.9 and no shims and there is no rubbing at all. You need to be a little more specific with your goals are.

 

295/70/18. I like the idea of 285/70/18 but there are only a few tires in that size available. I am running America Racing ATX 201's with a 40mm offset.

 

40mm is close to factory wheels at 60mm. Some have rubbed the uca with factory wheels and bigger tires.

 

^This. I’m told the 2.5” setting will be a stiffer ride.

 

Ride quality might be better using shims at 1.9 setting. You’ll get almost a 3” lift and since you’re not adding additional preload to get the lift it should ride better. Make sure to get bumpstop extenders though

 

I have the 6112 at 1.9". I used the CB half inch shim on the driver's side. I installed the +1CB shackles and 5160 bilsteins on the rear.
The ride and handling are excellent.
I intend to run 295-70-18 (34") tires.
Currently I have the factory Michelin AT2.

 

I liked the idea of a little more offset with the wheels but with a black truck and a gravel road I have enough issues without spraying crap all over the side of the truck. Maybe I can set up a "gofundme" to lay down 3000 sq ft of asphalt...

 

Also, I know the ration is supposed to be 50:1 on the shims (1/2" shim = 1' of lift) but I never saw that much of a gain when I installed them solo. Maybe more like 3/4" or so. Ive read on here that 1" out of the CB shims is being generous.

 

Don’t forget his wheels are also likely wider than the oe wheel, so comparing the 2 offsets doesn’t provide a total picture of the tire clearance.

OP, set the shocks to the height you want. No shims. Why would you shim it if you can just set the shock to the higher lift setting

 

Because a really heavy battery sits in the front driver's side. I use an X2 27 F.

 

One shim is understandable in that instance. Many guys are just using shims for straight lift

 

Shims also supposedly ride a little better since it doesn’t add preload. So on paper 6112s set at 1.9” with a shim should ride better than 6112s at the top setting. But I doubt anyone would be able to feel it.

 

That is more likely the effect of a truck lifted 1.9 inches rides better than a truck lifted 2.5 inches in general. The truck weighs the same and in a neutral position is compressing the spring the same amount

 

Yes, but if you compress a spring that is already somewhat compressed it will be stiffer. Like i said, probably too little to notice but there is a different on paper.

 

Isn’t the weight of the truck going to compress the spring far more than you needed to get it on the shock?

I don’t know the complete answer either. Either way, as you lose down travel, ride gets far rougher

 

I have that set up and my UCA rest on the coils at full droop

 

Weight of the truck doesn’t really matter. Theoretically the spring is compressed the same with or without the shim. But it is compressed more if you set the 6112s at a higher setting. Shim just adds a little more lift. The more compressed the spring is, the less it can absorb.

 

Is the spring progressive?

 

Don’t know. Seems like it’s digressive from a quick google search.

 

This shit sounds like my dirt bike suspension and setting the sag....

 

Springs are rated in pounds per inch. Tundra spring rate is around 600 pounds per inch. The easiest way to think about this is

To compress a 600lb spring 1” it takes 600lbs

To compress the same 600lb spring 2” it takes 1200 lbs

The reason why preload (the way Bilstein shocks lift our truck) effects ride quality is because it is pre compressing the spring.

The easiest way to understand this is

600lb spring with 0” of preload requires 600lbs to compress its first 1”

600lb spring with 2” of preload (approximately the amount Bilstein shocks add to achieve lift) requires 1200lbs to compress that same inch.

These number obviously aren’t 100% accurate for the tundra just use them for reference. It also doesn’t factory in any weight the truck is already putting on the spring, the way the shock valving interacts with the spring or the factory preload setting. So while it literally takes twice as much weight to start compressing the spring the ride isn’t going to be twice as stiff with 2” of preload, but it will be noticeably stiffer.

My advice for your situation is if you like the ride quality you have now, add the shim, if you could stand the suspension being a bit stiffer add preload.