jeffw Posted May 31, 2016 Report Share Posted May 31, 2016 I finally had time to get our truck & trailer weighed. The NH DOT weigh station scales are open all the time, so I stopped in when the station was closed to get weights. I was able to get weights for just the truck and then the truck and trailer: Truck only: 22,740 Front axle: 10,200 Rear axles: 12,540 Truck and Trailer: 45,020 Front axle: 8,000 Rear axles: 21,640 Trailer axles: 15,380 The trailer has 3 axles with 215/75R17.5 tires from 5 different manufacturers (Bridgestone, Firestone, Geostar, Hankook & Linglong) thanks to the previous owner. It surprised me how much weight came off the front axle with the trailer on. The truck is has dual rear axles (i.e. not singled). Right now I'm running 110 PSI everywhere, but was wondering if I could bring the pressures down some to improve the ride quality. Thoughts? Thanks! -jeff 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
Imurphy907 Posted May 31, 2016 Report Share Posted May 31, 2016 There are charts out there that will tell you the min pressure to support X lbs of load based off the tire. But they are MFG. specific. but you "could" ball park it a bit. here is a link to one of the Good Year documents. https://www.goodyeartrucktires.com/pdf/resources/publications/2010_loadinflation.pdf Your size is on the 6th page. 2016 Road Warrior 420 2001 Volvo VNL 660 Alaska Based. Link to comment Share on other sites More sharing options...
HERO Maker Posted May 31, 2016 Report Share Posted May 31, 2016 Jeff, do you really have 9,100 pin weight on your trailer??? Rear of truck hitched = 21,640, - unhitched rear, 12,540 = 9,100??? Rocky & Sheri Rhoades '01 Volvo 770 2016 DRV Mobile Suites, HoustonHERO Makers Ministry Link to comment Share on other sites More sharing options...
HERO Maker Posted May 31, 2016 Report Share Posted May 31, 2016 Is your trailer nosed down? BTW - before I had my bed built, I thought I had a heavy pin weight of 7,100 lbs! After bed, I took 900 lbs out of that basement. Rocky & Sheri Rhoades '01 Volvo 770 2016 DRV Mobile Suites, HoustonHERO Makers Ministry Link to comment Share on other sites More sharing options...
phoenix2013 Posted May 31, 2016 Report Share Posted May 31, 2016 Very nice set of numbers, here we go. Truck and trailer weight minus truck weight only. 45,020 - 22,740 = 22,280 Therefore the trailer weight is 22, 280 lb Trailer weight minus the trailer axles weight 22,280 - 15,540 = 6,900 Therefore the pin weight of the fifth is 6,900 lb Front axle truck loaded minus front axle truck empty 10,200 - 8,000 = 2,200 Therefore the front axle off load is 2,200 lb Truck rear axle loaded minus axle off loaded 21,640 - 12,540 = 9,100 Load difference on that axle Pin weight plus front axle off load 6,900 + 2,200 = 9,100 Yippee, isn't basic math grand! Trailer weight vs. pin weight 22,280 vs. 6,900 = 31.9% You definitely do not have a "floater"! Link to comment Share on other sites More sharing options...
GlennWest Posted May 31, 2016 Report Share Posted May 31, 2016 I have 30% on my Teton. Will get mine weighed soon hopefully. Still waiting on driving test 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
jeffw Posted May 31, 2016 Author Report Share Posted May 31, 2016 Jeff, do you really have 9,100 pin weight on your trailer??? Rear of truck hitched = 21,640, - unhitched rear, 12,540 = 9,100??? The trailer's a race car hauler. It's got a generator and fuel tank for the generator right up front, so I'm not surprised it's heavy up front. The trailer axles are rated at 8,000 pounds, FYI. Also, I only had 1 car in the trailer at the time. A second car would add about 2,000 pounds over the axles. Hopefully I can get over the scales when we have 2 cars in it. 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
jeffw Posted May 31, 2016 Author Report Share Posted May 31, 2016 Very nice set of numbers, here we go. Truck and trailer weight minus truck weight only. 45,020 - 22,740 = 22,280 Therefore the trailer weight is 22, 280 lb Trailer weight minus the trailer axles weight 22,280 - 15,540 = 6,900 Therefore the pin weight of the fifth is 6,900 lb Front axle truck loaded minus front axle truck empty 10,200 - 8,000 = 2,200 Therefore the front axle off load is 2,200 lb Truck rear axle loaded minus axle off loaded 21,640 - 12,540 = 9,100 Load difference on that axle Pin weight plus front axle off load 6,900 + 2,200 = 9,100 Yippee, isn't basic math grand! Trailer weight vs. pin weight 22,280 vs. 6,900 = 31.9% You definitely do not have a "floater"! Henry: Any concern with that pin weight on the ET Sr? 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
jeffw Posted May 31, 2016 Author Report Share Posted May 31, 2016 There are charts out there that will tell you the min pressure to support X lbs of load based off the tire. But they are MFG. specific. but you "could" ball park it a bit. here is a link to one of the Good Year documents. https://www.goodyeartrucktires.com/pdf/resources/publications/2010_loadinflation.pdf Your size is on the 6th page. Thanks for that. I've got goodyears on the drive tires, which are likely the only ones I would want to reduce much. I think the steers are Bridgestone. I'll see if I can find their similar doc.... 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
jeffw Posted May 31, 2016 Author Report Share Posted May 31, 2016 I've got 295/75R22.5 on the drive axles. 22,000 pounds over 8 tires gives me 2750 pounds per tire. The goodyear PDF starts at 4500 pounds at 70 PSI for that size. I assume I don't want to go all the way down to 70 PSI to give some margin of error. What would be a reasonable tire pressure to see if it improves ride quality? 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
rickeieio Posted May 31, 2016 Report Share Posted May 31, 2016 I've got 295/75R22.5 on the drive axles. 22,000 pounds over 8 tires gives me 2750 pounds per tire. The goodyear PDF starts at 4500 pounds at 70 PSI for that size. I assume I don't want to go all the way down to 70 PSI to give some margin of error. What would be a reasonable tire pressure to see if it improves ride quality? I'd say that with the difference between 2750 actual weight/tire, and the chart starting at 4500/tire, you already have a pretty good margin at 70 psi. KW T-680, POPEMOBILE Newmar X-Aire, VATICAN Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row Young enough to play in the dirt as a retired farmer. contact me at rickeieio1@comcast.net Link to comment Share on other sites More sharing options...
HERO Maker Posted May 31, 2016 Report Share Posted May 31, 2016 " Very nice set of numbers, here we go. Truck and trailer weight minus truck weight only. 45,020 - 22,740 = 22,280 Therefore the trailer weight is 22, 280 lb Trailer weight minus the trailer axles weight 22,280 - 15,540 = 6,900 Therefore the pin weight of the fifth is 6,900 lb Front axle truck loaded minus front axle truck empty 10,200 - 8,000 = 2,200 Therefore the front axle off load is 2,200 lb Truck rear axle loaded minus axle off loaded 21,640 - 12,540 = 9,100 Load difference on that axle Pin weight plus front axle off load 6,900 + 2,200 = 9,100 Yippee, isn't basic math grand!' This is so right on!!! Must not be on pain drugs yet! Or, I'm still on mine. I wonder how core math would have come out? Rocky & Sheri Rhoades '01 Volvo 770 2016 DRV Mobile Suites, HoustonHERO Makers Ministry Link to comment Share on other sites More sharing options...
phoenix2013 Posted May 31, 2016 Report Share Posted May 31, 2016 Rocky, you got to the same place, just didn't subtract the axle weight transfer. I'm really in the bad way popping Vicodin on a fairly "good" schedule waiting for the day when I become the member of the hive. Link to comment Share on other sites More sharing options...
phoenix2013 Posted May 31, 2016 Report Share Posted May 31, 2016 Henry: Any concern with that pin weight on the ET Sr? You are on the high side of the Sr. and on the bottom of the Super Sr. I wouldn't be concerned if yours is the latest Sr. model. (Sorry can't tell from jeffw who you are). Upgrade to Super Sr. is relatively "painless", should you want to do it. Link to comment Share on other sites More sharing options...
jeffw Posted May 31, 2016 Author Report Share Posted May 31, 2016 Hi Henry: This was Reese Wayne Hunt's truck. Your wife told me it's Serial # 770. -jeff 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
jeffw Posted June 1, 2016 Author Report Share Posted June 1, 2016 You are on the high side of the Sr. and on the bottom of the Super Sr. I wouldn't be concerned if yours is the latest Sr. model. (Sorry can't tell from jeffw who you are). Upgrade to Super Sr. is relatively "painless", should you want to do it. I'll try to give a call tomorrow to talk about the Super Sr. upgrade. Is that something Stephen Winter in NH could do for us? We're outside of Boston... 2007 Volvo 780 Volvo D12D, 465hp, 1650 ft/lbs tq., ultrashift Link to comment Share on other sites More sharing options...
OU812 Posted June 1, 2016 Report Share Posted June 1, 2016 Hi jeffw I also run about the same weight with my TC and 26 ft. 3 axel trailer, All your number are real close. The thing I use is a thermo "red" eye heat gun(Harbor Freight), to find out tire temp. Cool tire just last longer. Adjust the tire pressure, according to the load. Some times with car, sometimes without, and all.... the other toys. I just put a new set of 14 ply. 16 on the trailer. Just got the trailer builder tire wore out. Also did a axel alignment. two axel were out 1/4 inch. Will see. OU812 Link to comment Share on other sites More sharing options...
peety3 Posted June 1, 2016 Report Share Posted June 1, 2016 It surprised me how much weight came off the front axle with the trailer on. I finally had time to get our truck & trailer weighed. The NH DOT weigh station scales are open all the time, so I stopped in when the station was closed to get weights. 2,200 pounds off the front axle vs. 6,900 pounds pin weight. That's a 3.13:1 ratio. Does that match your [wheelbase]:[centerline of tandem to hitchpin centerline] ratio? Making a guess using 230" wb, is your hitch about 73" aft of tandem centerline? Link to comment Share on other sites More sharing options...
phoenix2013 Posted June 1, 2016 Report Share Posted June 1, 2016 I'll try to give a call tomorrow to talk about the Super Sr. upgrade. Is that something Stephen Winter in NH could do for us? We're outside of Boston... Steve could do it with no problem, he was actually involved with the development and the original installation of the Super Binkley head prototype. He hasn't done any upgrades but I would provide him with all the know how how to do it quickly and efficiently. You'd have to be patient with me for a while, I'm scheduled for a surgery next month so I am just finishing the work that I have in the pipeline and then will need a month or two to "recover", before I start on hitches and heads again. The conversion involves replacing the four smaller air bags with one large one and the round Binkley head with square Super Binkley that I manufacture. It also includes other improvements to increase its weight carrying capacity. Send me couple of pictures of the hitch, particularly the front of it, so that I can determine if it needs other things, yours was built during the "transition" period from the older design to the new design so I'm not certain what improvements it actually has. Link to comment Share on other sites More sharing options...
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