Hondo's 2006 Roadtrek 210 Popular Build

[booster]

Originally Posted by Hondo

Ok, I can already tell you that the rear hub doesn't have the bolts, you can see it in this pic-



I could do a rear sway bar after moving the genset aft, something that is on the to-do list now.

As far as shocks go, all new Bilstiens are installed. So what to do is the question. I don't want to have the front end jouncing me, it's really unnerving at speed, and it needs to be corrected.

Installing higher rate springs will increase the lift, correct? I could do that to correct the jounce problem, then I'd have to increase the rear lift as well. I would think that 1 inch additional would be the most that I'd want to do - your opinion?

I think most here would agree that going 1" is not enough for either clearance or handling. Most of the Roadtreks are so low in the front that doing a 2-2.5" lift will put them right where Chevy wants them to be based on the measured trim height. To get that is easy with aftemarket springs and will match the rear height well, measured at the wheelwells. So basically, no real reason to go under 2" of lift, and shouldn't need to go higher for normal type driving conditions. You likely don't have a macerator, so that will give you some break on clearance, but it it usually the tank valves that take the hit.

Doing the lift with the springs will give you the suspension geometry that is was designed for because of having the right trim height. It will also make it much easier to get a good alignment with settings that make for the best handling, without the feeling of "herding cats" as one member phrased it. Only a spring change, so no spindles, pucks, or anything else. The springs are readily available and have been used by several members, but they are not off the shelf brand name products, although the spring shop has now started making them in bulk lots due to selling so many. It makes it all much simpler.

Here is a link to a very long discussion about lifts and and wheel offsets. It is mostly up to date. The springs you would get would be the ones from Bill Erb at Valley Spring Works in California. They are a bit under $350 a pair delivered.

Photog's Lifted Suspension 2009 Roadtrek 190V - Class B Forums

The only rear swaybar you will find as far as we know will be by Hellwig and require the generator move. It is an excellent bar if you have the room.

[Hondo]

Adding the new springs to the 4 inch lift spindles?

The spindles already provide 3-4 inches of lift. Won't adding the new springs add even more lift?

As it sits right now clearance is great. It does have a macerator.

This is somewhat confusing, wasn't aware that the spindles were going to be a problem.

So here's where I'm at-

I have the Boulder Offroad 4 inch lift with 4 inch spindles/knuckles, new upper control arms and ball joints, new shocks all around and new leaf springs. The stock springs are installed up front and the bumpers are basically resting on the knuckle and this is causing handling issues and needs to be corrected.

Are you recommending using the spring you recommended with the new knuckles or going back to stock knuckles?

If I do go with the new springs, will it increase the lift further in the front thus requiring additional lifting blocks in the rear?

Sorry to ask all these questions but this was all unexpected. I read Photogs thread before I did the lift and after talking to Boulder Off Road that it would be a simple lift.

[booster]

Just to give you some light reading in your "spare" time here are a few more links to stuff on the site, as you seem to be interested.

Wheel offsets, shows how and when we discovered it and what folks have done to address it.

Wheel offsets, particularly Roadtrek Chevy - Class B Forums

Our homebuilt rear swaybar is in the Photog thread on the previous post



Switch to full floater axle

Axle weight capacity (GAWR) - Class B Forums

Cooling fans, dual fans at the end

2400cfm trans cooling fan? - Class B Forums

Getting the weights by wheel

http://www.classbforum.com/forums/f5...corner+weights

[Hondo]

Thanks, I am more than interested, I'd like to solve the bump stop issue on the front end without removing all the new parts and wheels/tires.

[Hondo]

Lots of good info Booster, lots to think about.

[booster]

Since you are in Colorado, you may want to talk to the guys mentioned in this discussion. They did a front spring, rearch rear for the poster a while ago. They may have a solution for you concerning your existing parts.

http://www.classbforum.com/forums/f8...lift-5525.html

[Hondo]

It looks like a set of Otto-Max TTC-1617 front springs (going over all the springs again & again) installed in the installed Boulder Offroad knuckles (like Photog's Final setup) should cure the bump steering problem. I will speak with them about that tomorrow.

Still looking at the rear swaybar you did Booster - an awesome mod! I'd like to find a simpler solution, maybe a local shop can get it done without moving the genset.

[booster]

Originally Posted by Hondo

It looks like a set of Otto-Max TTC-1617 front springs (going over all the springs again & again) installed in the installed Boulder Offroad knuckles (like Photog's Final setup) should cure the bump steering problem. I will speak with them about that tomorrow.

Still looking at the rear swaybar you did Booster - an awesome mod! I'd like to find a simpler solution, maybe a local shop can get it done without moving the genset.

The Otto-max springs are not the same as they used to be and will do something like 4" of lift by themselves. They don't sell any springs recommended for Roadtreks anymore, it appears. The Erb springs would be the way to go, as they will get you off the bumpstop, and give in the 2+ inches of lift, putting the suspension in the right place, but depending on how high the knuckles raised you I think they are 3" usually, you are going to get very high. Photog has stated that with the knuckles and springs the handling was better than just knuckles, IIRC, but still "trucklike". With just springs and airbags most say they get good driveability improvements, and even more if a rear bar is also installed. Very few have used knuckles so we have little information from others.

Photog did have a rear bar put in his, it is listed in the thread. It was a smallish (compared to the Hellwig) Ford bar, that was welded to the frame, and I don't recall how to the axle housing. It did hang pretty low, but you look because he had pics in the thread.

Personally, if you don't need more than 2" of lift for clearance, and likely you don't as you mentioned 1" being enough, I would take the knuckles out and go back to your stock ones, but with the 2" spring lift. Strictly my opinion, though.

[Hondo]

Originally Posted by booster

The Otto-max springs are not the same as they used to be and will do something like 4" of lift by themselves. They don't sell any springs recommended for Roadtreks anymore, it appears. The Erb springs would be the way to go, as they will get you off the bumpstop, and give in the 2+ inches of lift, putting the suspension in the right place, but depending on how high the knuckles raised you I think they are 3" usually, you are going to get very high. Photog has stated that with the knuckles and springs the handling was better than just knuckles, IIRC, but still "trucklike". With just springs and airbags most say they get good driveability improvements, and even more if a rear bar is also installed. Very few have used knuckles so we have little information from others.

Photog did have a rear bar put in his, it is listed in the thread. It was a smallish (compared to the Hellwig) Ford bar, that was welded to the frame, and I don't recall how to the axle housing. It did hang pretty low, but you look because he had pics in the thread.

Personally, if you don't need more than 2" of lift for clearance, and likely you don't as you mentioned 1" being enough, I would take the knuckles out and go back to your stock ones, but with the 2" spring lift. Strictly my opinion, though.

Hmm, no, I said I'd need an additional 1 inch of lift to get off the bumpstops. With the Boulder Offroad spindles it's up at least 3 inches now in the front.

I need more clearance because I go off pavement, mountain and desert. Getting 1 -2 inches of lift would get the suspension up to a safer level.

Possibly get some springs made based upon the published specs.

It's going to take some research for sure -will be calling Erb.

[Hondo]

Quoted for easy reference-

Originally Posted by booster

Just based on general curiosity, I went back over all the spring information I could find around here, too see if there was now enough to actually make sense and give some predictability.

We now have information on several springs, and the results they give on the vans related to ride height. Most of it makes pretty good sense, and when taken in total, it makes me wonder whey there was so much trouble getting the "right" springs made.

The original Tufftruck 1617's that Photog and I have (may or may not still be available)

17.7" free length-same as the OEM spring
8 coils of 1.050" wire
2026lb/in spring rate per Photog
Spring compression 2.5"
Spring compressed height 15.2"
Height change at wheelwell 2.0"

The first shot, softer/longer version from Tufftruck (1618?) that Photg got

19.7" free length
1427lb/in spring rate per Photog
number of coils unknown, but probably about 9, wire diameter probably 1.000"
Spring compression 3.5"
Spring compressed height 16.2"
Height change at wheelwell 4.33 "

The second shot, softer/longer version from Tufftruck (setdown 1618?)

18.7" free length
1425lb/in spring rate
8 coils of 1.000" wire
Spring compressed 3.5"
Spring compressed height 15.2"
Height change at wheelwell 2.0"


The Bill Erb springs that were made (same as Mexican Doctor's?) but were not able to be installed

18.0" free length
8 coils of 1" wire
Probably 1425lb/in spring rate as the spring is nearly identical to the setdown 1618 above, just slightly shorter
Spring compressed 3.5"
Spring compressed height 14.5"
Height change at wheelwell 0.37"


The OEM spring we all love to hate

17.7" free height
6+ coils of probably 1.000" wire
Spring rate of about 1488lb/in based on ride height differences to known rate springs
Spring compressed 3.36"
Spring compressed height 14.34"
Height change at wheelwell baseline"

Now the assumptions and measurements that can get us all into trouble

Assuming 2150# on each front wheel (rated max load-Photog is heavier)
Stock wheel offset of 28mm positive, with stock suspension
2.33 ratio of wheel to a-arm pivot to spring centerline to a-arm pivot. Measured on on our van.
2" increase in front ride height with the first generation 1617 springs

Calculations

The load on the spring is 5000# (2150# X 2.33 ratio)

How much each spring is compressed is in red above (5000# divided by springrate)

Compressed height of the spring is in green above (free height minus spring compression)

Change in height at wheelwell is shown in blue above ( difference between OEM spring compressed heightand new spring compressed height X 2.33 ratio

What is the end result?

The original Tufftruck 1617's and the Tufftruck setdown 1618's both wind up 2" above stock ride height based on the calculations and on observations. Makes sense. This puts the van right on factory desired ride height

The Tufftruck first attempt 1618 long springs would give you 4.33" lift at the wheelwell and would put the suspension too high. Photog saw this in his testing.

The Bill Erb spring would only raise the van about 3/8" at the wheelwell. This one didn't make sense until the springrate of the OEM spring was calculated. At 1488, it is stiffer than the Erb spring so the Erb extra length doesn't all go to lifting the van higher. The higher rate of the OEM spring would most likely be because it has less coils (steeper wind angle) which makes springs stiffer. This also makes sense, but the springs were never installed to get actual lift numbers.

The 1617 is 36% stiffer than stock

All the 1618 versions and the Erb springs are about 4% softer than the OEM springs.

From all this, it looks like the setdown 1618 from Tufftruck is the spring to get if you want to keep the ride the same as stock, but get 2" of lift. The hard part to understand is why they had so much trouble getting there. All we can assume is that Tufftruck was tunnel visioned on increased capacity, along with height increase. Their spring calculations may also have shown that the 1" wire springs would have shorter life with the bigger loads on them, so they wanted to keep the life up on them by going to the 1.050 wire. Or maybe they just wanted to keep OEM free height so they could be put in without a spring compressor.

What is of interest to me now is why Photog would be seeing too low damping in the down direction of his shocks. The springs he has are actually a little bit less stiff than stock, the shocks should match the springs well as they are very near OEM rate, so they shouldn't be overpowering the shocks. If they are getting overpowered, it should have been much worse with 1617's he used to have in his van. Perhaps it has to do with the raised spindles, which are designed for the van, but invariably change something in the geometry. It is likely that at the same wheel offset, the scrub radius would change, so the tire contact may be moving on the road differently with suspension compression and decompression than it did stock.

Net conclusion is that it all does make sense, the results match the predicted. The set down 1618 looks like the spring of choice for most folks, unless they are way overweight, looking for the best handling on smooth roads, or reducing sway as much as possible. We will know more about them as Photog gets more miles on them, to make sure no other issues, like interference, show up.

One issue that may, or may not, be of concern is that with the setdown 1618, we have as spring that puts the van at factory ride height, and with slightly reduced spring rate, but it does have a couple of extra coils, also. It would be interesting if Photog could look at how much room is between the tight side of the coils, total, compared to how far it is to bump stop. The factory spring would probably have close to 2" more spring travel available before going "solid", compared to the setdown 1618. Going solid with 5000# base spring load, plus the bump or dip force would almost certainly break something. A simple cure would probably to use one of the Timbrin style, taller, bumpstops if it does turn out to be an issue.

Also shown is that the Erb spring is nearly an OEM, and would not give anwhere near the lift required to get 2". Other than length the Erb spring seems to be nearly identical to the setdown 1618. There should not have been an issue putting the Erb springs in, however, as the setdown 1618 would require considerably more compression and Photog did that when he put his in.

[booster]

The list of the springs from the other thread probably needs a bit of updating, but we can't edit so hasn't been done.

The stock spring is listed at 1.00" wire, which some may or may not be. We have also seen folks say they had .90 or .94 in the vans, so there is likely a range.

I think most of the rest of it is pretty good, especially the measured dimensions that Photog gave. The spring rates for those is also close to what the calculators give.

The only remaining issue is that the early information on the Erb spring that was used on that list was based on information at the time, and we have repeatedly seem folks getting higher lift from the Erb springs than the list shows, which is still not totally explainable. I talked to Erb a while ago and he says he shoots for a 2" lift over "what most of them run at stock", so there will obviously be some variability on how much lift you get, but they should be close the same height when done, with variances due to wheel weights. 210s will often be higher because the big overhang reduces front weight an increases rear weight compared to the 190s.

The latest report gave the lift on a 190 at 3.80" with an estimate it would go down .5 with settling, so the Erb springs seem to be running on the higher rather than lower side. It will be interesting to see what Erb has to say about the whole thing.

With the current availability ease of getting the Erb springs, I will be putting in a set in the near future. That will allow me to get some more precise height expectations and impressions on ride quality in comparison to what we have with the Tufftruck ones we currently have. My guess would be that Erb is getting more spring rate in his spring, compared to what the calculators would give, maybe with wind style or materials, but I don't know that.

[booster]

I misunderstood the additional 1".

If you just need 1" in the suspension, there are likely cheaper springs that will do that. Moog makes a bunch of them in 1.031 wire. Husky also, IIRC. You would gain about 3/8" clearance at the bump stop, which may be a bit on the low side, but surely better than sitting on or right above it all the time.

[Hondo]

3.80 inches of lift?

That sure seems like a lot more than was previously posted, and much more than I need on my already lifted RT.

1 1/2 - 2 inches is what I'm thinking would be ideal- just need to ask Erb if the springs can be dialed down or find another spring maker.

[Hondo]

Originally Posted by booster

I misunderstood the additional 1".

If you just need 1" in the suspension, there are likely cheaper springs that will do that. Moog makes a bunch of them in 1.031 wire. Husky also, IIRC. You would gain about 3/8" clearance at the bump stop, which may be a bit on the low side, but surely better than sitting on or right above it all the time.

I see no reason not to get a set of springs made that duplicate Photog's results.

Tufftruck (setdown 1618?)

18.7" free length
1425lb/in spring rate
8 coils of 1.000" wire
Spring compressed 3.5"
Spring compressed height 15.2"
Height change at wheelwell 2.0"

He is using the same spindles that I am and getting springs made that solve the bump stop problem is my goal.

Any idea how far the bump stock spacing is on a stock van? I guess that I could measure that.

[markopolo]

Originally Posted by Hondo

Also, the leaf springs are new & a higher capacity - not stock.

As far as the weight goes, that was without anyone inside and IIRC full fuel and water in both tanks. The slip shows 3,540 front, 5020 rear and 8,560 total. you could add 300 lbs for water if it was empty.

GAWR 6084 lbs, GAWF 4,300 lbs

I'm late to this topic but thought I'd mention that your front weight seems way off compared to other Chevy/GM owner posts.

I'd get it weighed again. Photog's 190 was 4200 in the front. The lightest front weight I ever recorded for my GM van was 4020. It has never been under 4000 lbs.

[Hondo]

Originally Posted by markopolo

I'm late to this topic but thought I'd mention that your front weight seems way off compared to other Chevy/GM owner posts.

I'd get it weighed again. Photog's 190 was 4200 in the front. The lightest front weight I ever recorded for my GM van was 4020. It has never been under 4000 lbs.

Yeah, I agree, I'll do that with full fuel and water.

I had it weighed a few months ago at a truck stop using Cat scales-

3540 steer axle, 5020 drive axle

each axle on it's own scale/pad.

[booster]

Originally Posted by Hondo

Yeah, I agree, I'll do that with full fuel and water.

I had it weighed a few months ago at a truck stop using Cat scales-

3540 steer axle, 5020 drive axle

each axle on it's own scale/pad.

The weight to me seemed low from the initial total weight given early on, and that front does look very low.

IIRC, Photog even had some weighings at over the 4300#. Our 190 is consistently over 4K also, and was close to 4300# with full gas and all tanks full, but no food, or personal stuff except what stays in the van all the time.

Here is a weight label from a Roadtrek manual in 2007 showing the old way to calculate capacity, and also dry weight.



8250 dry which would be with only full fuel, no people, or option weights. The generator will add a bit under 150# so 8400#. A 160# person would get the weight to what Hondo got. If all the water tanks were full, you might get another 300# on the front, another person 200# would just get you to 4K on the front, so it does sound really low. He does appear to have the spare tire carrier, which would put him higher than his measured total, but reduce the front weight.

The weights just seem low to me also. The weight label would show that a typical 210 should be about 9200# with two people in it and full water and fuel. Hondo is showing nearly 700# lighter than that. Another trip to the scales certainly would be in order, I agree, and with full fuel and water. Getting as close to traveling weight is always good when getting weighed as it is so easy to underestimate how much weight you put in.

[Hondo]

I just filled the water tanks and will be off to have it weighed at the scales after I fill it up with fuel and will be weighed without me in it (200 lbs).

[booster]

I finally found the weighing information that had been posted quite a while ago, and it turns out to be 2006 Roadtrek 210 on its way home from purchasing.

[Hondo]

Ok, just returned from the scales. This time I used a state certified single scale vs Cat's 3 pad scale setup.

Weighed the front axle 1st, then the entire vehicle, then the rear axle.

• Nobody in the vehicle
• Full fuel
• Both water tanks full
• basic items including tools and tire chains (rear storage area)
• Propane tank full
• Dishes, silverware, 2 fold up chairs, other basic items

Front Axle - 3,600 lbs
Rear axle - 5,540 lbs
Total vehicle weight - 9,140 lbs

Previous (April 2017) Cat scale weights-

Front Axle - 3,540 lbs
Rear axle - 5,020 lbs
Total vehicle weight -8,560

The difference is 580 lbs, so I must have weighed it the 1st time without the water & fuel tanks full. Add in the new larger BFG tires and larger leaf springs and that about makes up the difference.

The GVWR is 9,600 lbs so that leaves me with 460 lbs payload with everything full. Add another 250 lbs if traveling without water in the main tanks (6 gallons in the interior tank) and that brings the payload up to 710 lbs.

I'm not sure why others have weighed more than my RT, it's been weighed twice with the results almost identical- maybe it was the passengers onboard . The front axle and total weights would be 300-400 lbs higher with 2 people inside at the time it was weighed.