Opinions on bilstein 5100 for front and rear 2.1 setting in the front.
Are they durable? How many miles do they typically last? Is the drive quality better than factory?

 

If the leveling coil-overs (5100's, FOX, etc.) use the same bottom and top mounts as stock, and the same coil spring of the same diameter as stock, centered over the strut like stock, and have as much down-travel as the spacer-equipped stock strut, would it not also have the same control-arm/spring rubbing issue as the spacer setup? Do they use offset mounting bolts or something to move the strut/spring inboard and out of the way of the control arm?

I've been watching all the leveling strut videos I can find, and from what I have been able to see, the leveling strut mounts look exactly like the OEM. And some leveling struts (like the 5100) re-use the existing OEM springs, so I don't think there is a smaller coil OD at work here to provide more clearance.

 

It’s not how it sits leveled, it’s the amount of droop at full extension that causes the upper control arm to hit the coil. The length of the shock at full extension limits the amount of droop. The spacer setup doesn’t, it makes the whole spring and shock assembly move down by whatever the amount of lift, so if the spring moves down by an additional 1.5-2 inches, this is when the upper control arm hits the spring coils. The coilover kits and shock replacement kits regardless of the spring perch won’t let the suspension droop more than the maximum extension of the shock itself. This would only happen over an aggressive bump or catching a bit of air.

 

Understood.

That would mean that the coil-over level struts have less down-travel (when measured from a resting/neutral position) than a spacer setup? Since in either case, the tire is moved 2" further down in its overall stroke range, but yet the coil-over level strut is limited to the same overall down-travel measurement as stock, right? (thus preventing over-extension and spring/control arm contact)

So, if I am understanding correctly, the choice is either more frequent "topping out" of the front suspension (with the coil-over struts, due to less available down-travel than stock) or less topping out but more control-arm/spring contact with the spacers due to that deeper-than-stock front suspension stroke?

 

Correct. You’d technically lose overall suspension travel compared to stock with leveling struts or coilovers. I think the real answer is just to forego the level and do a full lift of at least 4 inches to fully modify the suspension geometry, which obviously adds more cost, but I’m sure like many the next issue is clearing the garage opening. If not lifting I could see doing the Bilsteins at the 1.25 lift with a conservative offset to get a 34” tire. It should be the best allrounder for clearance, tire size, and suspension geometry while still fitting in a standard garage.

 

What are solid alternatives to Bilstein 5100s since they're on back-order for several months?

 

Rancho Quicklifts

https://realtruck.com/p/rancho-quick...s/rho-rs999910

 

Im running the Eibach protruck coilover and rear shocks, they also have a front strut like the 5100 if you dont want to go full coilover. Very happy with the performance of this kit. Initially had 2.5" of lift and I have since turned them down to about 1.75".

 

Those are a very good alternative, especially with the cost factor figured in. I bought a set used from a member here for a very good price. Initially had them on my '17, and now on my '20, zero complaint.

 

Faster/cheaper install, too, since they are complete units. No need to swap springs. I was really on the fence between the two and I think I would've been happy with the Ranchos as well.