Advice on Custom Suspension?

[BusFiend]

Hi Gang,

I'm still in the planning stages for my skoolie project. The end result will be full-time lived, 30ish foot, diesel pusher. The rig will have either a stock or added "basement".

I'm thinking suspension now. Currently thinking about having it re-sprung for finished, wet, conversion weight. This should give me a good ride and height for over-the-road use. I'm also thinking about adding pairs of 5000 lb "helper" air bags front and rear that would allow an additional 4-5" of ride height, to slowly navigate rutted fire roads in national parks/forests.

Any thoughts and advice, regarding drivetrain angle/length and any other issues that I might be missing, are greatly appreciated.

Thanks!

~Alden

 

[Stu & Filo. T]

Hi Gang,

I'm still in the planning stages for my skoolie project. The end result will be full-time lived, 30ish foot, diesel pusher. The rig will have either a stock or added "basement".

I'm thinking suspension now. Currently thinking about having it re-sprung for finished, wet, conversion weight. This should give me a good ride and height for over-the-road use. I'm also thinking about adding pairs of 5000 lb "helper" air bags front and rear that would allow an additional 4-5" of ride height, to slowly navigate rutted fire roads in national parks/forests.

Any thoughts and advice, regarding drivetrain angle/length and any other issues that I might be missing, are greatly appreciated.


Thanks!

~Alden

When I was shopping for insurance the company ask me " Has the suspension been modified in any way?"

 

[jake_blue-SKO]

When I was shopping for insurance the company ask me " Has the suspension been modified in any way?"

And the answer is always 'no'

 

[BusFiend]

When I was shopping for insurance the company ask me " Has the suspension been modified in any way?"

Thanks! I'm actually in discussions with a custom coach company near me about doing a 10-12" roof-raise, gutting, insulating, under-belly storage, exterior skinning and new window framing. I will add the suspension work to the discussion. I will want full RV coverage for my conversion. It appears the only (?!?) way to obtain this is with a "professional conversion". From the way the discussions are currently heading, it should cost me $15-20k, plus the cost of the donor bus. I have a $40k budget to play with. Not sure yet if this is the path I'll take.

 

[BusFiend]

And the answer is always 'no'

The problem comes if a claim is ever made against the policy. If you misrepresented your rig, they could deny the claim...

 

[Carytowncat]

$40k budget is a sweet one indeed. If ever i had that i would try to hire one of the craftsman from Skoolie to do the work; some of the pics on here are amazing.

 

[retiredChemist]

My 2c would be to look at adaptive damping rather than spring resets and air bags. Provided you're within the tare to Gvm window of course . Manufacturers spend alot to make the suspension work well enough over most roads. Following on from the system BMW use, it'd be a simple case of switching from road standard s
Damping to off road with extra compression damping and less rebound damping. Which would keep it as complianced when on road.

I'm presently looking at this through a beaglebone black and a few sensors and some magneto rheological fluid.

 

[BusFiend]

My 2c would be to look at adaptive damping rather than spring resets and air bags. Provided you're within the tare to Gvm window of course . Manufacturers spend alot to make the suspension work well enough over most roads. Following on from the system BMW use, it'd be a simple case of switching from road standard s
Damping to off road with extra compression damping and less rebound damping. Which would keep it as complianced when on road.

I'm presently looking at this through a beaglebone black and a few sensors and some magneto rheological fluid.

Thanks!

I'm thinking that our skoolies are way over sprung. A 26k lb GVWR chassis/suspension often ends up at 17 or 18k lbs wet, after conversion. I assume that's one reason they bounce around a lot. My primary goal is to have two ride heights; one for on pavement, the other for rutted fire roads. That's why I'm thinking about going the spring/airbag combo.

 

[retiredChemist]

They don't make versions of the bus with air bag suspension? Might be easier to swap in air bags and modify a kneeling valve.


Early Volvo b10m had a very similar system for getting onto ferries.saves reinventing an already engineered solution.

Tyre pressure needs to be modified for the lighter load too. But that's a black art in itself.

 

[retiredChemist]

What's your suspension travel by the way?

 

[Iceni John]

Thanks! I'm actually in discussions with a custom coach company near me about doing a 10-12" roof-raise, gutting, insulating, under-belly storage, exterior skinning and new window framing. I will add the suspension work to the discussion. I will want full RV coverage for my conversion. It appears the only (?!?) way to obtain this is with a "professional conversion". From the way the discussions are currently heading, it should cost me $15-20k, plus the cost of the donor bus. I have a $40k budget to play with. Not sure yet if this is the path I'll take.

With that budget and those needs, why are you reinventing the wheel? How about a 30' or 35' transit bus - plenty of headroom, enough underfloor space for bins or lockers there, air suspension. Or an older 35' road bus such as a MC5 or a 41xx GM - huge underfloor storage lockers, highway gearing, good windows. MCI even had a more recent 35' bus that was a rebadged Dina from Mexico. There's plenty of interesting options out there. Spending up to $40k on a skoolie, albeit a heavily-converted skoolie, makes little sense to me. Heck, how much do first-gen 35' Temsa tour buses go for?

If you really want to go the skoolie route, maybe think about a Blue Bird TC1000 - short, high roof, available air suspension, and a totally flat floor.

John

 

[turf]

buy what you want in the first place. endless changes that cost more than the value of the vehicle just aren't worth it.

Do a good job on the conversion and ask your insurance agent about an "agreed value" policy and save your receipts.

 

[BusFiend]

Don't have a bus yet. Trying to put a design together first and purchase a donor to best fit the design.

Interesting thought on modifying the kneeling valve. First thought is school buses with front air seem to be rare. Retrofitting a complete front air suspension may be beyond my budget. What does it take to add a kneeling valve to the rear? Collapsing the air bags for kneeling has to lower the spring rate of the system. How would spring rate be calculated?

 

[Stu & Filo. T]

Thanks! I'm actually in discussions with a custom coach company near me about doing a 10-12" roof-raise, gutting, insulating, under-belly storage, exterior skinning and new window framing. I will add the suspension work to the discussion. I will want full RV coverage for my conversion. It appears the only (?!?) way to obtain this is with a "professional conversion". From the way the discussions are currently heading, it should cost me $15-20k, plus the cost of the donor bus. I have a $40k budget to play with. Not sure yet if this is the path I'll take.

That seems way underestimated for having a company perform the work, I know a fellow Skoolie who had his done professionally & he is in over 100 Grand.

 

[BusFiend]

That seems way underestimated for having a company perform the work, I know a fellow Skoolie who had his done professionally & he is in over 100 Grand.

That's what I thought too. Apparently the big things are the least time consuming. The interior and detail work soak up the labor. I'm told they should be able to turn over the things I listed above in 80 hours of shop time. Materials are fairly inexpensive. I don't know. They've been putting out nice coaches for a few decades. I have no doubt they would want close to $100k to do the entire project.

 

[RossAnabel]

Hi Gang,

I'm still in the planning stages for my skoolie project. The end result will be full-time lived, 30ish foot, diesel pusher. The rig will have either a stock or added "basement".

I'm thinking suspension now. Currently thinking about having it re-sprung for finished, wet, conversion weight. This should give me a good ride and height for over-the-road use. I'm also thinking about adding pairs of 5000 lb "helper" air bags front and rear that would allow an additional 4-5" of ride height, to slowly navigate rutted fire roads in national parks/forests.

Any thoughts and advice, regarding drivetrain angle/length and any other issues that I might be missing, are greatly appreciated.

Thanks!

~Alden

Been thinking along those lines too, but might go with a dog nose with limited under belly storage, especially in the center sections. We won't be full time, so storage isn't a critical factor.

 

[somewhereinusa]

Care to share name of conversion company?

 

[BusFiend]

With that budget and those needs, why are you reinventing the wheel? How about a 30' or 35' transit bus - plenty of headroom, enough underfloor space for bins or lockers there, air suspension. Or an older 35' road bus such as a MC5 or a 41xx GM - huge underfloor storage lockers, highway gearing, good windows. MCI even had a more recent 35' bus that was a rebadged Dina from Mexico. There's plenty of interesting options out there. Spending up to $40k on a skoolie, albeit a heavily-converted skoolie, makes little sense to me. Heck, how much do first-gen 35' Temsa tour buses go for?

If you really want to go the skoolie route, maybe think about a Blue Bird TC1000 - short, high roof, available air suspension, and a totally flat floor.

John

Thanks, John!

If I was staying on pavement, I'd have purchased a converted MC7, Buffalo or first gen Le Mirage already. The big problem with coaches is the low ground clearance. I plan on traveling rutted fire roads. I want 8-10". I can get that with a skoolie. I'm 6'3" barefoot. With insulation, almost any bus would need at least a 10" roof raise. I can keep the raised skoolie to 11'6" or less. A raised coach is pushing 12'6" to 13'.

The TC/1000 is not a good candidate. First of all no RE version. Deal breaker for me. There are other issues with the 1000.

Remember, this will be my full-time home and office for the foreseeable future.

 

[BusFiend]

Care to share name of conversion company?

Walker Coach. They only do custom work. They've never done a skoolie before and are intrigued.

 

[BusFiend]

buy what you want in the first place. endless changes that cost more than the value of the vehicle just aren't worth it.

Do a good job on the conversion and ask your insurance agent about an "agreed value" policy and save your receipts.

Thanks, turf! That's why I want a fairly clear plan and budget before I buy a bus.