viter
Adventurer
I guess it has been updated and they are back in US - http://earthroamer.com/tab_xpedition_travel/central_america.html
EarthRoamer Expedition: Central America
- Thread starter Scott Brady
- Start date
xcmountain80
Expedition Leader
Not so sure about the low pro street tires on the F-Series.
Aaron
Aaron
Not so sure about driving back and forth to Costa Rica in 6 weeks.
xcmountain80
Expedition Leader
True!
Aaron
Aaron
tires
I believe the tires used on the big Earthroamer are Michelin XDA2 in 295/60R22.5 size. The tires are M&S rated.
I think Bill Swails chose this particular tire because it's not nearly as tall as most tires for 22.5 inch wheels are. This tire is only 36.5 inches tall, while other 20 inch or 22.5 inch tires with aggressive off-road tread are over 40 inches tall. The smaller diameter means Earthroamer doesn't have to re-gear the F550 axles.
Chip Haven
I believe the tires used on the big Earthroamer are Michelin XDA2 in 295/60R22.5 size. The tires are M&S rated.
I think Bill Swails chose this particular tire because it's not nearly as tall as most tires for 22.5 inch wheels are. This tire is only 36.5 inches tall, while other 20 inch or 22.5 inch tires with aggressive off-road tread are over 40 inches tall. The smaller diameter means Earthroamer doesn't have to re-gear the F550 axles.
Chip Haven
xcmountain80
Expedition Leader
Yeah just as I started to read this post I Knew where it was going, Yea I agree something similar to a crane tire or the military tires like CodyLX450 is running. But hey if that work for him than more power to him. Though just out of my own curiosity why a 22.5" rim at all? Why not a 15 or 16 with whatever tread he desired with a mega load rating. To each there own, I would never put 22.5' on my 250. Though outside of that I love the concept of these vehicles, make me think that this would be a sweet mobile jobsite vehicle.haven said:
Aaron
tires
I know that Bill Swails searched long and hard for a smaller tire that could support the weight of the Earthroamer on single rear wheels. The Goodyear MT/Rs had very little reserve capacity.
The MT/R 37X12.5 R17, as used on the original Earthroamers, is rated at 4080 lbs.@65 psi., the maximum recommended pressure. The Michelin XDA2 used on the Earthroamer today is rated to carry more than 5000 lbs per tire @85psi, and up to 7000 lbs per tire @130psi. Both tires are 36.5" tall.
There are several options in the 20 inch rim size in the Michelin catalog, but these are tire sizes used on military vehicles. Our adventure in Iraq is absorbing the inventory of these tires, making it very hard to find a steady supply.
In addition, these "tactical" tires are very tall. For example, the Michelin XZL 365/85R20 is rated to carry more than 7000 lbs @ 70 psi, but it's 45 inches tall. You'd have to re-gear the F550 and add a body and suspension lift to make these tires work.
Outside North America and western Europe, tires to fit the 22.5 inch rim size are a lot more common than 17, 19.5 or 20 inch rims.
Chip Haven
I know that Bill Swails searched long and hard for a smaller tire that could support the weight of the Earthroamer on single rear wheels. The Goodyear MT/Rs had very little reserve capacity.
The MT/R 37X12.5 R17, as used on the original Earthroamers, is rated at 4080 lbs.@65 psi., the maximum recommended pressure. The Michelin XDA2 used on the Earthroamer today is rated to carry more than 5000 lbs per tire @85psi, and up to 7000 lbs per tire @130psi. Both tires are 36.5" tall.
There are several options in the 20 inch rim size in the Michelin catalog, but these are tire sizes used on military vehicles. Our adventure in Iraq is absorbing the inventory of these tires, making it very hard to find a steady supply.
In addition, these "tactical" tires are very tall. For example, the Michelin XZL 365/85R20 is rated to carry more than 7000 lbs @ 70 psi, but it's 45 inches tall. You'd have to re-gear the F550 and add a body and suspension lift to make these tires work.
Outside North America and western Europe, tires to fit the 22.5 inch rim size are a lot more common than 17, 19.5 or 20 inch rims.
Chip Haven
xcmountain80
Expedition Leader
Well I guess you are somewhat limited as to what you can run. If I remeber correctly a couple years ago the trek wrench team were running aournd the country demoing new mtnbikes and they had an E350 and for some reason I happened to notice the higher pressure rating, which just now prompted me to wonder what the offroad camping conversion vans were running for tires. I would imagine they would have to be high pressure and offroad worthy in smaller than a 22.5. But all that said if you've done the research and know what the heck your doing than more power to you. I just thought for a South American Expo I would have used a more offroad tire, but like I said somewhere if it works it works and if your happy I'm happy. I love the concept of the vehicle.
Aaron
Aaron
I have been considering using the same tires the Earthroamer uses. Does anyone know how well they perform in mud and sand? I was told by Rickson that you can not airdown these commercial truck tires. I guess the bead is different and the bead will pop easily, also the sidewalls are not very flexible and can be damaged. Ideally I want a tire I can confidently drive on the Pismo dunes. I have looked at the 37 inch Toyo MT which are rated for 4300 lbs each. These with Stauns double bead locks will perform great in mud or sand. My concern is I am within 500 lbs of their upper limit on weight.
charlieaarons
Explorer
milo12 said:
The Earthroamer tires IMHO aren't worth much offroad due to the short sidewalls and the 22.5" pattern having poor bead retention at low psi. For offroad potential you want a tire with a high diameter to rim size ratio.
If you are looking for largish tires capable of low psi with a high load capacity look at Michelin military tires in smaller sizes - 16" rims. In other words 9.00R16 or 11.00R16 XZL or 325/85R16 XML. The 9.00 is rated for 4240 lb, 11.00 4600 lb, 325 5070 lb. And all have published offroad low pressure inflation tables.
By the way, the main reason Earthroamer doesn't use 365/80R20 or especially 365/85R20 Michelins is that tires this diameter and weight would quickly destroy wheel bearings, axles etc on a loaded F550. Look what happened when Petersen's put 395/85R20 XMLs on a non loaded F350. Axles and diffs in pieces.
335/80R20s would probably be OK on a 550, they are only 40.7" and "only" 121 lbs, rated at 5780 lb.
Charlie
Last edited:
Charlie, Thanks for the info. Did some searching around for XML tires, not easy to find in stock. Do I need custom wheels made to fit my truck and have the right bead shape to work with these tires at low pressure? If so any recommendations?
On second thought I may have other problems. First, I'm sure I will need custom 16 inch wheels no matter what. I doubt there are 16 inch wheels with 10 bolt lugs and the offset I need. Second, I don't know if a 16 inch wheel will clear the brakes on a Dodge 5500. I will need to go to the dealer and check since I don't have the truck yet.
On second thought I may have other problems. First, I'm sure I will need custom 16 inch wheels no matter what. I doubt there are 16 inch wheels with 10 bolt lugs and the offset I need. Second, I don't know if a 16 inch wheel will clear the brakes on a Dodge 5500. I will need to go to the dealer and check since I don't have the truck yet.
Scott Brady
Founder
charlieaarons said:
Just an FYI, but we have run 25 psi front and 35 psi rear on the big EarthRoamers in sand and soft terrain (even in the dunes). We typically run them at 45/55 for the trail and have yet to lose a bead.
charlieaarons
Explorer
325/85R16 XMLs have a tread patch of 94 sq" at normal load and pressure, 295/60R22.5 XZA1= 70 sq". The 325s can be run as low as 10 psi depending on load. Michelin publishes low speed/low pressure tables on their site at www.michelintransport.com , you have to keep it in French to get the detailed tables. If you have trouble finding them PM me.
The big problem would be fitting 16" rims on newer vehicles. 16" may or may not fit on a Dodge 5500. Loadwise it would be near perfect and it is as heavy and as big as I would go for a heavily loaded "super" Dana 60, though if pressed to 20" a 335/80R20 MPT XZL would be OK (2" taller at 40.7" - about the same width). In the 141K version it has even higher load capacity - 5780 lb/tire. Don't go any bigger than that.
Regarding sourcing, a cooperative dealer can order them even from Europe if you know the inventory #. For the 325/85R16 it's 37984. For the 335/80R20 141K it's 62159. They are both marked as "limited" availability in North America, which means there should be a few new ones in North America.
Dollar Tire in Edmonton Alberta sometimes has decent used 325s for a good price.
They both weigh about the same, ~120 lb/tire, the 335 has a bigger footprint at 109 sq".
You would need reversible rims with a carefully calculated offset to have a near congruent track and proper front offset. You don't want to overload your front wheel bearings or screw up your steering geometry. Unless you go with different front and rear rims.
I always recommend carry a second unmounted spare with tires of this sort.
I also advise paying some attention to maximum speed ratings if loaded heavily: 62 mph for the 325s and 65 mph for the 335s. I wouldn't exceed that for long distances more than 5 mph and then I'd add at least 5-10 psi over the proper psi for that load. If loaded over 80% of max do not exceed max speed for more than 3-5 miles under any circumstance.
A cautionary story: a certain un-named guy has/had a certain German made truck with a camper (not me!!!). The motor was up-rated to 350 hp and he disconnected the governor for top gear. He put on 16.00R20 XZLs which are rated at 55 mph but because they are taller gave him a top speed of 85 mph. He was travelling (maybe too fast?) and had a blowout and rolled the truck. He is OK I guess, but an expensive problem! Disclaimer: This story does not refer to any certain individual....but is probably true.
Think hard about those tire speed ratings! If you really want/need to travel all day at 75-85 mph you must have little relatively tiny hard smooth high pressure tires. I'm personally fine with 60 mph. Rotational kinetic energy increases as the square of the speed.
Charlie
The big problem would be fitting 16" rims on newer vehicles. 16" may or may not fit on a Dodge 5500. Loadwise it would be near perfect and it is as heavy and as big as I would go for a heavily loaded "super" Dana 60, though if pressed to 20" a 335/80R20 MPT XZL would be OK (2" taller at 40.7" - about the same width). In the 141K version it has even higher load capacity - 5780 lb/tire. Don't go any bigger than that.
Regarding sourcing, a cooperative dealer can order them even from Europe if you know the inventory #. For the 325/85R16 it's 37984. For the 335/80R20 141K it's 62159. They are both marked as "limited" availability in North America, which means there should be a few new ones in North America.
Dollar Tire in Edmonton Alberta sometimes has decent used 325s for a good price.
They both weigh about the same, ~120 lb/tire, the 335 has a bigger footprint at 109 sq".
You would need reversible rims with a carefully calculated offset to have a near congruent track and proper front offset. You don't want to overload your front wheel bearings or screw up your steering geometry. Unless you go with different front and rear rims.
I always recommend carry a second unmounted spare with tires of this sort.
I also advise paying some attention to maximum speed ratings if loaded heavily: 62 mph for the 325s and 65 mph for the 335s. I wouldn't exceed that for long distances more than 5 mph and then I'd add at least 5-10 psi over the proper psi for that load. If loaded over 80% of max do not exceed max speed for more than 3-5 miles under any circumstance.
A cautionary story: a certain un-named guy has/had a certain German made truck with a camper (not me!!!). The motor was up-rated to 350 hp and he disconnected the governor for top gear. He put on 16.00R20 XZLs which are rated at 55 mph but because they are taller gave him a top speed of 85 mph. He was travelling (maybe too fast?) and had a blowout and rolled the truck. He is OK I guess, but an expensive problem! Disclaimer: This story does not refer to any certain individual....but is probably true.
Think hard about those tire speed ratings! If you really want/need to travel all day at 75-85 mph you must have little relatively tiny hard smooth high pressure tires. I'm personally fine with 60 mph. Rotational kinetic energy increases as the square of the speed.
Charlie