why upgrade to 17.5" wheels

[jerryneal]

I see where fivers have wheel upgrades from 16" to 17.5". Does this improve height? Weight capacity? Better tire options? Planning to buy new Michelins for our 39' Gateway before we take our long winter trip. Wondering if this upgrade is beneficial before I make the tire purchase.

[Alie&Jim's Carrilite]

Tire diameter is within 1/4" between 16" and 17.5". So your suspension height and overall height remains the same. Technically it DOES NOT increase your weight rating. It gives you a higher safety margin on the carrying capacity of the tire alone.

Saliun tires in the 17.5 are getting good reviews lately. Several folks here are running them so far without issue.

[GeorgiaHybrid]

Jerry,

 

A lot of people are having issues with blowouts in the 16 inch tire sizes and move up to 17.5 rims and tires (if their axle is capable of bolting them up). Load ratings per tire in the 17.5 series are in the 4,800 pound per tire range and you rarely hear of a tire giving someone a problem.

[mptjelgin]

I see where fivers have wheel upgrades from 16" to 17.5". Does this improve height? Weight capacity? Better tire options? Planning to buy new Michelins for our 39' Gateway before we take our long winter trip. Wondering if this upgrade is beneficial before I make the tire purchase.

On some trailers the 16" tires are running close to their maximum capacity, so folks have upgraded to 17.5" wheel/tires to get a more comfortable margin on the tires. We have 16" load range "G" tires on our trailer. They have significant excess capacity and have worked well for almost 5 years we've had the trailer, and when the time comes we'll replace with the same tire. I think that the decision comes down to how much cushion you want on the tires rated capacity.

[grumpydoc]

Missing one important piece of info, how much weight is currently on each of your 16" tires. Secondly, have you had troubles with blow outs or other tire failure issues with your current 16" tires? We had a heavy tri-axle 5er with D range 16" tires that were running at their max weight rating and suffered several tire failures. Our current rig is even heavier but is on H range 17.5" GY 114s and we have not had any issues and run them at 100 psi. If your rig is maxed out on the current tire's rating and/or you have had multiple tire failures then consideration of 17.5s is reasonable. As mentioned above the tire diameters are essentially the same but in switching to 17.5s you will need new rims. When getting the rims you will need to be sure you get the right stud size, a stud centered rim, with zero offset. Much of this is spelled out in Mark and Dale Bruss's website somewhere. Be sure you get a tire that is speed rated to 75 mph like the Goodyear and I believe the Michelins. You can order tires and rims from several places like trailertiresandwheels.com and they will drop ship them to you already mounted and balanced with all necessary hardware. The 17.5" tire is widely available in part due to the fact that it is often used in commercial operations like low boy trailers and therefore is usually at most truck stops. If on the other hand you are not having trouble with your current tires and are not near their max rating then switching may only be an exercise in spending money. When we switched our previous tri-axle several years ago it cost $3000, don't know what it will cost today. Best Wishes, Jay

[jerryneal]

Being an engineer for a long time, I always took the "over design, extra capacity" route for safety margins. Had 2 blow outs last October, 500 miles apart. What a mess! Had 3500 miles on the tires and the remaining 2 were seperating. My bad for not doing better research before we bought the new fiver.

 

I like the idea of safety margin and the trailer tire always seems to be the weakest link. Just looked at the Salium 17.5 tires and I get it. Another 1000 pounds of capacity each plus a higher mileage rating. The difference in cost over 16" Michelins almost makes up the difference for both tire and a wheel purchase.

 

So help from those who've gone this route. Order a wheel and tire package online from one of the trailer/tire sites or find a local dealer who specializes in trailers and axels?

[jerryneal]

Jay, what's the URL for Bruss's site? Google search only gives me the 2016 HDT rally.

[mptjelgin]

If you've had two blowouts with the other two tires separating then I would say you are definitely a candidate for a tire or tire/wheel upgrade.

[mptjelgin]

http://www.dmbruss.com/zFullTimeLifeStyle/FTLS_Tires_SizeChange.htm

[Mark and Dale Bruss]

This is covered in Tire_Size_Change. The biggest driving factor was to get away from the Goodyear G614 16" G Rated tire. The G614 is a great tire for its original purpose for low-boy trailers. But it construction did not survive well in fifth-wheel use where there is tremendous lateral force on the tire tread where turning the trailer during parking, especially in triple axle configurations,

 

At the time, the only tire in the marketplace with any kind of brand recognition was the Goodyear G614. There are rumors that some construction changes have happened to the G614 that may make it more suitable for triple axle fifth-wheel trailers. There are some more sources for 16" G rated tires but few, if any, from the major brands.

 

By going to the G114, or equivalent 17.5" tire, I no longer had to run at maximum tire pressure to get the tire load capacity desired.

 

Before believing you will have more load capacity, remember, the axles, spring, shocks, and other chassis hardware have to have margin too. I wanted a different tire to use and having some margin in the tire pressure was a bonus.

 

The unfortunate thing is that trailer manufacturers cheap out on chassis equipment. G rate and H rated rims cost the same and not much more than a E rated rim. The G114 H rated tire is lower in cost that the G614 because it fits a larger market, electronics semi trailers. They are also more prevalent because of the commercial use.

 

I am a Goodyear man and the G114s I upgraded to have been fabulous. I have aged out the original upgrades. I just wish I could have ordered 17.5's in the beginning.

[grumpydoc]

Jerry, Dale answered your question about his site We went the order from trailertiresandwheels.com route and had them dropped shipped to a local business location. Installed them myself, it was an all day job for this old man and I would not do it again! Would point out that the Goodyear G614 is not to be confused with the GY G114 tire. The G614 is a G range 16" tire and the G114 is an H range 17.5" tire in spite of the G in it's "name". Like Dale I am a Goodyear fan, they have probably the most dealers in the US and have honored claims for damages from failures of their tires. Many people on this forum have recounted their failures of GY G614s and their dealings with Goodyear Claims. My impression from those comments is most were satisfied with the resolution of their claim with GY. Besides price one might consider availability, Dealer support and claim resolution in brand selection. Based on your tire failures I would recommend moving to 17.5s for your rig. Read Dale's webpage and understand what you need to order to make the transition, I think you will be safer and happier, Best Wishes, Jay

[jerryneal]

Many thanks for the time and advice. Load hasn't been a problem as much as cheap tires from the dealer. Stranded in Tennessee last year, I had no alternative but to purchase Chinese again. I've got 5,000 miles on a set of 14 ply steel belts in the tread and 6 in the side wall Gladiators. I feel like the Loan Ranger and can't find anyone else running similar. I only have 2 axels, but for some reason, I've had my share of jack knife backins this year. I'm not going to press my luck and will take your advice and look locally first when I return to Georgia.

 

The website was a wealth of information, have it bookmarked and I definitely plan to use to narrow my search to make the transition.

[travelinbob]

I may be wrong but I think the 16" tires have a max speed of 65 MPH while the 17.5 is 75 MPH. With that being said I see many 5th wheels passing me at 75

or more MPH on 16" tires. My comfortable speed is 62 even though I can go 75 if I need to.

[Big Greg]

I believe the suspension systems, especially tires, is one of the most common failures on fifth wheels. We had one blowout on a GY G614 tire in 2009. Luckily there was only minor body damage. I was very pleased with GY's warranty claims department. We upgraded to GY G114 17.5" tires and wheels from Trailer Tires and Wheels in Ohio and have had zero tires problems since. A no brainer upgrade in my mind. Greg

[mptjelgin]

I may be wrong but I think the 16" tires have a max speed of 65 MPH while the 17.5 is 75 MPH. With that being said I see many 5th wheels passing me at 75

or more MPH on 16" tires. My comfortable speed is 62 even though I can go 75 if I need to.

The 16" G614 tires on my trailer are rated for 75 mph. The 16" Michelin XPS Rib tires that I had on my previous fifth wheel have a "Q" Speed Rating which corresponds to 99(!) mph. But I believe that ST tires are speed rated for 65 mph. So the 16" size is not the determining factor.

[GlennWest]

I am using the Michelin XPS Ribs 16" is on my Teton but I have 3 axles also. Trouble free.

[Mark and Dale Bruss]

Tire load rating is the issue. There are 16" D Load range tires that 6 will only have a tire load capacity of a little short of 16K lbs, light for a Teton and yet that is what the standard tire was. Go to E Load Range and you go up to a little over 18K lbs and still marginal on a 20K GVWR trailer. 6 G rated 16' tires would have a tire load capacity of 22.5K lbs.

 

So just saying 16" tires of any brand says little as to the capabilities of the tires. Load Range Rating is important.

[GlennWest]

We are less than 15k on axles. have a 25% pin. Tires give us 18k rating. Plenty of margin.

[Mark and Dale Bruss]

To say "less than 15k on axles. have a 25% pin" is a risky statement. My Travel Supreme weighed at 22,250 lbs. We have a 4725 pin weight (21%) which is a tire load capacity of 17,825 which would be covered by E Load Range tires and yet when weighed, one tire was over the E load rating. That is why my trailer was delivered with G Load Range tires as standard equipment.

 

Only when your trailer has been weighed per wheel do you know you have "plenty of margin".

 

I set my tire load capacity margin by using the gross weight divided by the number of tires. The pin weight is my margin.

[GlennWest]

It's trouble free. I am currently at Livingston Escapees. When I leave we will get it Smart Weighed. On the Cat scales we were 14,800ish. I came with D range Marathons. This made my decision. I have 18k capacity.

[Big Greg]

I agree that you have to know individual tire loads, ours varies 470 pounds from the lowest to highest individual wheel load. Greg