Finally found some wheels and tires for the girl

[MarkEkberg]

I hope to have everything put together by tomorrow night. Road test on sat.

Din't kow about longer arms. Good to know.

 

[mwilson]

I am trying to decide how much air pressure I would run in those.

 

[AH64ID]

I am trying to decide how much air pressure I would run in those.

I would find the minimum pressure reccpmmended and run that.

 

[MarkEkberg]

I am going to start at 60 in fronts and 45 in rears.

Tires are rated for 120 lbs.

 

[JR]

Not sure how accurate your Smarty is but mine was never very close as far as punching in a number and the speed being accurate. I normally start at about a half inch under the actual tire diameter and then test drive against my GPS. From there I drop in 1/4" increments until I match my GPS.

 

[lpennock]

I am going to start at 60 in fronts and 45 in rears.

Tires are rated for 120 lbs.

Too low if I pulled the size correctly out of this thread.

A 255/70R22.5 has a miniumum pressure of 80 psi according to the Goodyear load tables. At 80psi they are rated fro 3970 on the duals and 4190 on the single wheel.

 

[AH64ID]

Not sure how accurate your Smarty is but mine was never very close as far as punching in a number and the speed being accurate. I normally start at about a half inch under the actual tire diameter and then test drive against my GPS. From there I drop in 1/4" increments until I match my GPS.

Mine too, but the Smarty uses inches and the a ECM uses rev/mile so there is a slight difference when we think diameter vs rev/mile.

My tires are 33.2" on the diameter but only 32.3" on rev/mile diameter. My truck is programmed at 32.05". I verify with my odo, not my speedo.

Too low if I pulled the size correctly out of this thread.

A 255/70R22.5 has a miniumum pressure of 80 psi according to the Goodyear load tables. At 80psi they are rated fro 3970 on the duals and 4190 on the single wheel.

Yep, and minimum pressure on xx.5" wheels/tires is there to keep the bead seated. The bead doesn't seat on xx.5" wheels like is does on Car/pickup wheels.

I emailed a Toyo about my M608z's and was told I could go as low as 70.

 

[lpennock]

Not sure how accurate your Smarty is but mine was never very close as far as punching in a number and the speed being accurate. I normally start at about a half inch under the actual tire diameter and then test drive against my GPS. From there I drop in 1/4" increments until I match my GPS.

Remember you have to use rolling diameter rather than Static/advertised diameter. Good starting rule of thumb on these large sidewall truck tires is rolling diameter is 90% of static diameter. Ideally you should just go get Rev/mile and use that to calculate rolling diameter or this chart will get you close.

http://www.ntwonline.com/Revolutions-Per-Mile-Chart.html

 

[mwilson]

Been a crazy day and I am just getting back to this. I went out and talked with the tire department manager about tire pressure for this unique situation. Being a low pro 22.5 truck tire they should be a 14 ply tire. With that being said and carrying a small amount of weight you could almost run them flat.....

He felt that you could safely drop to 50 psi if needed, but it will require you to check for any unusual wear patterns and heat build up. It would take a really rank side pressure or curb scrubbin' to unseat them at 50 psi. If any sign of funky wear then you will have to increase the pressure to find the happy medium between truck ride and tread wear.

 

[AH64ID]

I thought the same thing about 50 in my 19.5's, but Toyo Said 70 was the bottom side. 70 is 10 less than the published minimum, so they did give me some play room.

Just my 0.02, but it is probably worth emailing the manufacturer and asking. Tell them what weight will be on them when you ask.

 

[mwilson]

This is off the books advice, these are pretty stout sneakers with hardly any weight on them compared to what they are designed for. I would try it as long as the wear was good, I can't imagine how the truck would ride with 70psi in them dead empty.
You could get some air on a frost heave for sure....

 

[MarkEkberg]

Just took it out for a test ride in the pot hole east coast last night and down the highway today.

65 in fronts 45 in rears.

Ride is not different v/s 80 in the stock ones until you hit a big pot hole then it is worse. I am thinking I am going to bump it up to 80 and 50 and call it good.

Of course re tq everything tomorrow.

Tires are quiet, smooth and ride well.

 

[SnoKing]

Just took it out for a test ride in the pot hole east coast last night and down the highway today.

65 in fronts 45 in rears.

Ride is not different v/s 80 in the stock ones until you hit a big pot hole then it is worse. I am thinking I am going to bump it up to 80 and 50 and call it good.

Of course re tq everything tomorrow.

Tires are quiet, smooth and ride well.

Why not set the inflation via the inflation chart for the tire size. Snoking

 

[brods]

A tire designed for over 10K lbs is not going to have an inflation pressure listed for 3K loads. This 255 chart only goes down to 8,380 lbs for the lowest pressure : http://www.michelintruck.com/tires-and-retreads/selector/#!/info/xd2 As others have stated tongue in cheek, if the beads would stay on you could probably run with almost zero air pressure. Iirc one way to calculate inflation pressure assumed 20% of the full load was taken by the tire carcass, in this case that's over 2,000 lbs. Just for kicks it would be interesting to see those tires on the truck with no air in them to see how much they squat.

 

[AH64ID]

8,380 is the axle load, so 4,190lbs @80psi which is still overkill for nearly all loads.

I wouldn't run them lower than 70, bead purposes only.

 

[MarkEkberg]

I ended up going 75 front and 50 rears based mostly on load chart. Front of the truck is right around 6K if I remember right from forcing my dad to take it to the scales a few years ago.

Re torqued today. Nothing loose after 100 miles yesterday. Now I just need to get rid of the bike in the back so I can give it some juice.

 

[AH64ID]

6K on the front seems heavy, I am heavier than most and usually ± 5200lbs empty and 4800-5000 with the TT hooked up.

 

[lpennock]

I'm 4600 empty and 5100 with my cab over camper on a QCLB.