Non-dually?

[jumper.cables]

What is the technical term to describe buses that do not have dual rear wheels? Is it just "non-dually"? Thanks!

 

[PNW_Steve]

SRW.

Single Rear Wheel.

The only SRW school buses that I have ever seen have been built on 1-ton SRW chassis like the E350.

 

[Johnny Mullet]

PNW is correct! Single rear wheel is the term.

 

[jumper.cables]

Gotcha, thanks! What's involved with converting one to the other? Relatively "easy"?

 

[Mark_In_MA]

Gotcha, thanks! What's involved with converting one to the other? Relatively "easy"?

I'd say it depends on the size of the bus, and weather you're trying to add or subtract tires.

There are some trucks out there running "super singles" - one large tire with the load capacity to replace a pair of dual wheels. If you could find one with the right size and bolt pattern for a bus, you should be able to make the swap. (That's a big "if".) I think bus companies prefer having the dual tires because if one goes flat, you've still got one more to get the bus to the side of the road safely.



If you've got a van chassis or a cutaway, you're more likely stuck with whatever is under it now. I don't know of any companies making single wheels and tires to replace the duals on a cutaway van. If you left the factory axle and just left off a tire, you'd end up with a very narrow axle that would probably be unstable, and overload the tires.

I'm sure there are some off-road or 4x4 conversions out there that have done it, but I bet they use custom axles and/or subframes to support them.

You'd have the opposite problem mounting duals on a single rear wheel cutaway bus - the axle is too wide, and they'd stick out past the body of the bus. Other then it looking a little funny, and adding some unsprung weight to the axle, I don't think it would damage anything other then your fuel economy and tire budget. Aftermarket fenders can be purchased - people occasionally do it with pickup trucks.

 

[pbeggs]

I'd say it depends on the size of the bus, and weather you're trying to add or subtract tires.

There are some trucks out there running "super singles" - one large tire with the load capacity to replace a pair of dual wheels. If you could find one with the right size and bolt pattern for a bus, you should be able to make the swap. (That's a big "if".) I think bus companies prefer having the dual tires because if one goes flat, you've still got one more to get the bus to the side of the road safely.



If you've got a van chassis or a cutaway, you're more likely stuck with whatever is under it now. I don't know of any companies making single wheels and tires to replace the duals on a cutaway van. If you left the factory axle and just left off a tire, you'd end up with a very narrow axle that would probably be unstable, and overload the tires.

I'm sure there are some off-road or 4x4 conversions out there that have done it, but I bet they use custom axles and/or subframes to support them.

You'd have the opposite problem mounting duals on a single rear wheel cutaway bus - the axle is too wide, and they'd stick out past the body of the bus. Other then it looking a little funny, and adding some unsprung weight to the axle, I don't think it would damage anything other then your fuel economy and tire budget. Aftermarket fenders can be purchased - people occasionally do it with pickup trucks.

changing from dual to single on a cutaway van is as simple as getting the correct wheels,.. and possibly a spacer/adapter the rear axle is the same (on fords at least) the duals have a lot of offset where the singles have a lesser offset,.. then the issue of fenders comes into play duals stick out further

 

[o1marc]

I'd say it depends on the size of the bus, and weather you're trying to add or subtract tires.

There are some trucks out there running "super singles" - one large tire with the load capacity to replace a pair of dual wheels. If you could find one with the right size and bolt pattern for a bus, you should be able to make the swap. (That's a big "if".) I think bus companies prefer having the dual tires because if one goes flat, you've still got one more to get the bus to the side of the road safely.



If you've got a van chassis or a cutaway, you're more likely stuck with whatever is under it now. I don't know of any companies making single wheels and tires to replace the duals on a cutaway van. If you left the factory axle and just left off a tire, you'd end up with a very narrow axle that would probably be unstable, and overload the tires.

I'm sure there are some off-road or 4x4 conversions out there that have done it, but I bet they use custom axles and/or subframes to support them.

You'd have the opposite problem mounting duals on a single rear wheel cutaway bus - the axle is too wide, and they'd stick out past the body of the bus. Other then it looking a little funny, and adding some unsprung weight to the axle, I don't think it would damage anything other then your fuel economy and tire budget. Aftermarket fenders can be purchased - people occasionally do it with pickup trucks.

Aren't the wheels separate from inside to outside? If you ran only the outer one instead of the inner one, you would maintain the buses track width, though still have weight capacity and handling issues.
I see a lot of Gov Auction buses being sold with only single wheels in the back because the school keeps the good spares.

 

[Oldcarnut-SKO]

My bus is a 2002 E450 Thomas shorty. When I did the 4X4 conversion I forgot about the 4wd hub spacer on the front axle and ended up with a regular axle. Read on another forum about a guy who converted a similar ambulance to SRW by just purchasing heavier duty SRW rims and bolting them on. I did the same as I could not find dually from hub spacers for my D60 axle in the short amount of time I had.
Running standard rims front and rear my track is maybe 1 inch different between the front and rear now.
If I had kept the dually front end setup that would be a whole nother story. Front track would be much wider I assume even with the SRW rims in back.
Converting to DRW would entail the dually rims for the rear and (not sure but most likely) the rear brake setup as well. My rear disks are not in the wheel like my other rides but inbound closer to the center pumpkin.
The front you can leave alone which necessitates 2 spares (off set dually n standard) or you can find the whole spindle assembly to offset the track width and run only one spare. Your call.
I would not mind going back to a DRW but dont want 2 spares n they are not that great off road.

 

[sepudo]

My bus is a 2002 E450 Thomas shorty. When I did the 4X4 conversion I forgot about the 4wd hub spacer on the front axle and ended up with a regular axle. Read on another forum about a guy who converted a similar ambulance to SRW by just purchasing heavier duty SRW rims and bolting them on. I did the same as I could not find dually from hub spacers for my D60 axle in the short amount of time I had.
Running standard rims front and rear my track is maybe 1 inch different between the front and rear now.
If I had kept the dually front end setup that would be a whole nother story. Front track would be much wider I assume even with the SRW rims in back.
Converting to DRW would entail the dually rims for the rear and (not sure but most likely) the rear brake setup as well. My rear disks are not in the wheel like my other rides but inbound closer to the center pumpkin.
The front you can leave alone which necessitates 2 spares (off set dually n standard) or you can find the whole spindle assembly to offset the track width and run only one spare. Your call.
I would not mind going back to a DRW but dont want 2 spares n they are not that great off road.

I wonder *IF* someone is not going to come even close to the GVWR of the bus (mine is 24K lbs) could I remove the inner rear wheels and just run with the outer wheels without any negative effects?
(not asking if it's legal or safe or otherwise) just checking more mechanically would the drivetrain would *notice*
I'm also looking at removing/modifiying some of the leaf springs (already spoke with a suspension shop for the ok to soften the ride)

as a background, my bus currently sits are 14k lbs with a GVWR of 24,500 lbs. My entire build will be less then 3k lbs.

 

[Oldcarnut-SKO]

My bus was 9960 empty but (almost) full of fuel and the rims are 19.5s with a load rating of 4500 each. Tires are semi versions (not going out to check but IF I remember right E series). Only adding mid mounted sink/ stove combo and a fridge with a few motorcycles thrown in fer fun on the occasion. Im going bare bones. Springs are custom to accommodate factory rated 4k pounds in the rear alone so I should have no problems.
I think OP might be SOL though.

 

[bridg73988]

Couple notes...

Not safe mechanically to run only one dually wheel, it loads the axle flange and bearings with extreme bias.

When running "super singles" which is a tire/wheel that can replace a pair of dual wheels/tires, the vehicle is supposed to also utilize a TPMS, Tire Pressure Monitoring System to warn driver of a low tire.