International 3800 Frame Rail Width?

[dzl_]

I am hoping someone with an International 3800 might know the distance between the frame rails (inner edge to inner edge) or would be kind enough to peak under the bus with a tape measure. Frame rail height would be useful too, but not crucial. It would be much appreciated!






Edit: posted to wrong subforum, meant to post to Conversion General Discussion. My apologies. Mods please move this to the appropriate subforum if possible.

[Drew Bru]

Originally Posted by dzl_

I am hoping someone with an International 3800 might know the distance between the frame rails (inner edge to inner edge) or would be kind enough to peak under the bus with a tape measure. Frame rail height would be useful too, but not crucial. It would be much appreciated!






Edit: posted to wrong subforum, meant to post to Conversion General Discussion. My apologies. Mods please move this to the appropriate subforum if possible.

33" inner edge to inner edge, 9 5/8" top to bottom (inner edges)

[o1marc]

Go to the UserCP and put all your bus info and location in it so we can better address your issues.

[dzl_]

Originally Posted by o1marc

Go to the UserCP and put all your bus info and location in it so we can better address your issues.

No bus yet, I'm looking into a 1990 International 3800, Bluebird body, with a DT360, but I have some reservations about the particular bus and am looking into several alternatives as well. When I find the right bus, I'll make sure to update my profile.

Originally Posted by Drew Bru

33" inner edge to inner edge, 9 5/8" top to bottom (inner edges)

Thanks for taking the time to grab those numbers for me, I really appreciate it. Not the answer I was looking for though , I was hoping it might be possible to shove a full size spare between the frame rails. Oh well.

[Brad_SwiftFur]

Originally Posted by dzl_

.... I was hoping it might be possible to shove a full size spare between the frame rails. Oh well.

Not happening. Do like other buses with full size spares do (not common but they do exist) - hang the spare below the frame rails.

[dzl_]

Originally Posted by Brad_SwiftFur

Not happening. Do like other buses with full size spares do (not common but they do exist) - hang the spare below the frame rails.

I guess that'll have to be the direction I end up taking. Either that or build a rear spare tire mount like many of the overland vehicles do.

[Brad_SwiftFur]

Originally Posted by dzl_

I guess that'll have to be the direction I end up taking. Either that or build a rear spare tire mount like many of the overland vehicles do.

Good luck lugging a 200 pound tire four feet off the ground. Personally I'd go for an under-frame spare tire rack similar to what some road trailers use. A length of chain and padlock will offer some resistance to the spare tire going missing.

[dzl_]

Originally Posted by Brad_SwiftFur

Good luck lugging a 200 pound tire four feet off the ground. Personally I'd go for an under-frame spare tire rack similar to what some road trailers use.

Yeah, muscling a 200lb 40+ inch tire onto the back of the bus sounds like a bitch and a more traditional underbody spare mount would likely be much easier. But I plan to take the bus offroad fairly regularly so I'm hesitant to give up anymore underbody clearance than I need to. And the overland folks are often dealing with tires in the same ballpark as those found on buses, and have come up with a number of creative solutions, usually using some kind of mechanical advantage or hydraulics to make it easier. But I'm not as skilled or as rich as most of that crowd, soo.... we'll see.

[Brad_SwiftFur]

Originally Posted by dzl_

Yeah, muscling a 200lb 40+ inch tire onto the back of the bus sounds like a bitch and a more traditional underbody spare mount would likely be much easier. But I plan to take the bus offroad fairly regularly so I'm hesitant to give up anymore underbody clearance than I need to. And the overland folks are often dealing with tires in the same ballpark as those found on buses, and have come up with a number of creative solutions, usually using some kind of mechanical advantage or hydraulics to make it easier. But I'm not as skilled or as rich as most of that crowd, soo.... we'll see.

I've found my frame-to-ground clearance around 30" (rough guesstimate, air suspension inflated) but differential-to-ground clearance closer to 12". That will probably be the biggest off-road-ability factor. And unless you have a locking differential, I wouldn't expect to do much off-roading with it. These things are *Heavy* and will sink on soft ground or sand (does this sound like the voice of personal experience taking? From the files of "Been There, Done That", feel free to ask me how I know!).


Also, I'm guessing the "overland" folks you refer to are driving smaller vehicles such as lifted 4x4's? Those 40" mudder tires are *Much* lighter than the 16-ply heavy duty tires our buses use. Also, we run much higher pressures and "airing down" the tires for off road use won't be as effective as, say, a set of Mickey Thompson's.


I'm sure you could rig up a rear-mount carrier with a lifting mechanism but at what point does it become a complicated solution for a simple problem?

[dzl_]

You definitely make some good points

Originally Posted by Brad_SwiftFur

I've found my frame-to-ground clearance around 30" (rough guesstimate, air suspension inflated) but differential-to-ground clearance closer to 12". That will probably be the biggest off-road-ability factor.

You're right, differential and axle clearance are important (but don't necessarily limit you in practice if you choose smart lines), but equally or more important offroad are approach, departure, and breakover angles. My concern with mounting a spare below the frame is that it could substantially limit departure angle. But without having the bus in front of me or having more detailed measurements, I cant say how much of a limitation this would be. For a longer bus, an under frame spare probably wouldn't be an issue at all, for a shorter bus it might substantially limit it.

And yes, Ideally I would like to find a rear locking differential or limited slip. That + aggressive drive tires + a decent low gear, and some low tech self recovery gear and traction aids is about the best you can do without getting fancy and spending mucho $$

Originally Posted by Brad_SwiftFur

And unless you have a locking differential, I wouldn't expect to do much off-roading with it. These things are *Heavy* and will sink on soft ground or sand (does this sound like the voice of personal experience taking? From the files of "Been There, Done That", feel free to ask me how I know!).

Heavy is a double edged sword. I haven't driven anything nearly as heavy as a fullsize bus, but I do have experience with a heavily loaded camper van, and in some situations that weight on the drive axle is helpful (generally speaking it improves traction) and in other cases it hurts (sand, mud, soft ground). A skoolie is definitely not the most sensible choice for an off pavement vehicle, but for light to moderate off pavement travel I think they can probably hold there own with a few sensible modifications if you can avoid soft ground. That said, I definitely am not speaking from a place of experience so I might be being overly optimistic. But I do know that there are many similarly heavy vehicles that perform well offroad with the right modifications.

Originally Posted by Brad_SwiftFur

Also, I'm guessing the "overland" folks you refer to are driving smaller vehicles such as lifted 4x4's? Those 40" mudder tires are *Much* lighter than the 16-ply heavy duty tires our buses use.

I was referring to vehicles similar in size and weight to short to medium length skoolies (14k+ GVWR's). The 'expedition' overland vehicles are generally built for extended (or fulltime) self sufficient overland travel. Unimogs, MAN 4x4's, 4x4 Fuso cabovers, and LMTV conversions are some examples. The medium duty vehicles often stick to ~37 inch tires on a 19.5 or even 16 inch wheel, but the heavy duty trucks use 20 or 22.5 inch wheels and beefier tires than even buses and semis.

Originally Posted by Brad_SwiftFur

Also, we run much higher pressures and "airing down" the tires for off road use won't be as effective as, say, a set of Mickey Thompson's.

This is a very good point, and I think just an unavoidable factor of heavy GVWR vehicles. at the 11R22.5 tire size, its hard to find data or products specific to offroad performance. And it does seem like the ability to safely air down is questionable at best (I actually started a thread about this on another site and got some good feedback).

Originally Posted by Brad_SwiftFur

I'm sure you could rig up a rear-mount carrier with a lifting mechanism but at what point does it become a complicated solution for a simple problem?

Yeah, this is my thinking too, and why I was hoping I could mount it between the frame rails. Some of the $$$ expedition vehicles have very cool hydraulic rear rack systems that can easily raise and lower a 300lb tire and a motorcycle at the same time. But the added complexity and added cost of these systems is unappealing and quite possibly prohibitive.

On the other hand, I did see a pretty cool DIY skoolie rear deck build that used a small ATV winch and a pulley system to raise and lower the deck. The same general design could be applied to a tire mount.

But **** compared with roof raises, mounting VW's to the roof, and whatever you call this a rear tire rack isn't so ambitious


I didn't set out to write a full length novel, but it appears I did.... seems to be a recurring problem for me..

[Brad_SwiftFur]

I don't currently have a spare but if I choose to carry one I'll do one of two things. I'll either go with an underframe rack, likely right behind the drive tires (if I find a frame mounted lift similar to what some cars use, but made for these big tires, I'd consider that), otherwise I have a wheelchair lift and ~4 square feet inside the bus that will do nicely.