Parkliner Tire Rub issues?

[Birmingham1]

Originally Posted by Brian M. in NY

I second the motion!

Just had to update my avatar to show some of that ParkLiner luv'. Just finished painting in the carving on my campsite sign and this seemed a fitting way of celebrating!

I was wondering what they heck that was when it was unpainted...it looked like stamped metal or something. I had been meaning to ask.

It looks great! You will be easy to find at the campgrounds!

[ruscal]

This kind of issue is basically “teething problem” in the design process. Without the benefit of sophisticated mechanical design and modeling software there can be issues that arise requiring some corrections. Ideally a suspension designer would cycle the system to check parameters in all positions of travel. It is difficult to cycle a torsion axle due to the inability to remove the spring from the system. One would have to load the system with actual weight to bottom the suspension. Alternately an axle could be fabricated with bushings and no springs, and the trailer could be lifted with jacks to articulate the suspension through its travel. Another approach would be to use strings and rulers to try to approximate what would be expected, and then make a prototype to test. If it rubs, move something until it doesn’t rub. Then document the dimensions and go into production. The design more or less just evolves. In some cases the design is correct on paper, but slips occur in actual production which can cause these issues. Setting up solid fixtures and tooling instead of measuring tapes would help in that department.
I’m sure the manufacturer will figure out the best way to eliminate the rubbage issue. Existing units will possibly require a different fix than future ones. Changes to axle length or position, tire or wheel dimensions, fiberglass mold changes could fix it. They have a fine design that may just need a little tweek.
No worries,
Russ

[GPJ]

Originally Posted by ruscal

This kind of issue is basically “teething problem” in the design process. Without the benefit of sophisticated mechanical design and modeling software there can be issues that arise requiring some corrections. Ideally a suspension designer would cycle the system to check parameters in all positions of travel. It is difficult to cycle a torsion axle due to the inability to remove the spring from the system. One would have to load the system with actual weight to bottom the suspension. Alternately an axle could be fabricated with bushings and no springs, and the trailer could be lifted with jacks to articulate the suspension through its travel. Another approach would be to use strings and rulers to try to approximate what would be expected, and then make a prototype to test. If it rubs, move something until it doesn’t rub. Then document the dimensions and go into production. The design more or less just evolves. In some cases the design is correct on paper, but slips occur in actual production which can cause these issues. Setting up solid fixtures and tooling instead of measuring tapes would help in that department.
I’m sure the manufacturer will figure out the best way to eliminate the rubbage issue. Existing units will possibly require a different fix than future ones. Changes to axle length or position, tire or wheel dimensions, fiberglass mold changes could fix it. They have a fine design that may just need a little tweek.
No worries,
Russ

I'm not sure that sophisticated software would help in this case. My experience is that modeling software is a first step, but issues like this are worked out in the prototype stage. That's where you modify your design to deal with the reality that rears its ugly head when you test your prototype to extremes that would not normally be encountered.

The real issue to my mind comes from Chandlers post where he says "We have used three brands of axles, four brands of tires, and five brands of rims" - and they have only built about 35 units. This seems a rather bizarre situation and fraught with potential problems. Settle on a good brand and stick with it! Develop long term supplier relationships. Apart from the current problem - how do you deal with problems when they arise if there is very little parts commonality amongst the user base.

Anyway - that's my two cents - I'm looking forward to hearing the final resolution of this problem. Best wishes for a speedy resolution to Parkliner and all concerned.

[accrete]

Originally Posted by Birmingham1

...Your wife is a keeper!

30 years this Memorial Day weekend! It's been a SciFi Comedy adventure

[ruscal]

Originally Posted by GPJ

The real issue to my mind comes from Chandlers post where he says "We have used three brands of axles, four brands of tires, and five brands of rims" - and they have only built about 35 units. This seems a rather bizarre situation and fraught with potential problems. Settle on a good brand and stick with it! Develop long term supplier relationships. Apart from the current problem - how do you deal with problems when they arise if there is very little parts commonality amongst the user base.

I don't think Chandler is fickle in sampling available components at this early stage of his business. Suppliers don't treat small manufacturers much better than an individual. Thousands of sales gets their interest. The suppliers take care of their biggest customers first and then work down the pecking order. The little guy is lucky to get ANY parts. He will settle into a preferred supplier list after dealing with them for a while, and that will make it easier for his business to handle these unfortunate issues when they arise.
Russ

[Birmingham1]

Originally Posted by accrete

30 years this Memorial Day weekend! It's been a SciFi Comedy adventure

Congrats!

[accrete]

As an FYI... i ended up at a local tire Centre and had two tire pros look for solutions (they are also a certified dexter dealer/repair Centre) they said the easiest fix is a tire swap... They test installed a LTT 185R14 8 ply with an 1870 load rating that gave at least an additional 1/2” more clearance than what is now on there.

[gmw photos]

Originally Posted by accrete

As an FYI... i ended up at a local tire Centre and had two tire pros look for solutions (they are also a certified dexter dealer/repair Centre) they said the easiest fix is a tire swap... They test installed a LTT 185R14 8 ply with an 1870 load rating that gave at least an additional 1/2” more clearance than what is now on there.

Thom,
If you are going to swap tires, see my earlier post regarding this. Might be a good op to "up the quality" of chosen tire.

george

[accrete]

Here is a better shot after they took wheel off... Street side

[Jim Bennett]

Originally Posted by Birmingham1

(my trailer was several days late, which is why I ended up waiting on it...in fact, I helped clean it to speed things along the day I picked it up.)

My trailer was only hours late, and while they worked feverishly to get it done for me, I too helped out in the cleaning of it and a couple other small things. They were putting in a good effort, so I had no problem helping out at all. Folks from Vermont picked their 19 up just the day before and were quite impressed after seeing the readiness of mine, that it was done in the time it was.

Glad to see PL is taking care of the issue. That certainly is a tight clearance, though equates to minimal wasted space inside.

[accrete]

Originally Posted by gmw photos

...Might be a good op to "up the quality" of chosen tire.

Factory stock tire:
205/D14 Bias Ply - 6 ply with 1760lb cap

Possible solution tried as mentioned:
185/r14 Light Truck Radial - 8 ply with 1874lb cap

I'm not a tire guy, but the possible solution looks to be "up" in quality than factory stock?

[Francesca Knowles]

In my opinion, putting an LT tire on is not an automatic upgrade, and in this case could be a mistake. LT tires have more flexible sidewalls than ST's, which may only aggravate the problem here.

I also have a "bias" for bias-ply in trailer tires, so think the type chosen correct for the application...one more bit of attention to detail for which Parkliner should be congratulated.

But I'm sure we're about to find out that I'm in the minority here as to my type-of-tire opinions!

Francesca

[accrete]

Who knows?!

Though here in Oregon you can see many trailers with LT tires... Especially boat trailers.

But we are a strange lot & like or came too

[Ice-breaker]

If it was my trailer that was suffering from this issue, I would want to assure myself that the proposed solution is in fact a long-term solution. Given that many suspension systems will tend to "ride a bit lower" as the years go by, I would be a little wary of any solution that provides the minimum amount of clearance necessary at the present time (such as a slightly smaller tire). For me, I would be thinking in terms of adding a spacer between the frame and the axle to give both immediate and long-term clearance.

[Drumstick63]

I am not a tire expert so read this with that in mind.

The following two tires have some good reviews with trailer-folk. I believe both are Load Range D and spec'd at 25.6" diameter with 1874lbs rating at 65psi.

Kumho 857 185R14

Hankook RA-08 185R14

This 25.6" diameter is approximately 1/2 inch smaller in diameter (based on specifications) than the Hi-Run tires that Chandler has been shipping with the ParkLiner. Can you trust the specifications? Maybe not. It appears that manufacturers are not held tightly to the specifications as Chandler has found a disturbing variance in the diameter of the Hi-Run tires that he currently has on hand, with some being closer to 1 inch over the specification. That might explain the tire rubbing with a group of trailers shipped out around the same time with tires from possibly the same shipment.

Anyway the above tires give more clearance and may be the solution if it turns out to be a problem with inconsistencies in tire diameter. If Kumho or Hankook has better manufacturing tolerances, you may even be able to go up to their 195R14 which is approximately the same diameter as the Hi-Run tires.

If another manufacturer has tighter manufacturing tolerances, you might be able to use another 205/75/14 as that size has worked for ParkLiner in the past.

Again, I am not an expert with tires so please verify the above specifications and by all means, talk with an expert that knows tires, rims, ratings, psi, load, etc.!

Mark

[Byron Kinnaman]

Originally Posted by accrete

Who knows?!

Though here in Oregon you can see many trailers with LT tires... Especially boat trailers.

But we are a strange lot & like or came too

Some of us Oregonians that have been towing a Travel Trailer for a number of years will only use ST tires. ST tires are built for trailers, Light Truck tires are built for mostly for pick up trucks. Where's similarity?

[Glenn Baglo]

What would the manufacturer know about tires??

[gmw photos]

Originally Posted by accrete

Factory stock tire:
205/D14 Bias Ply - 6 ply with 1760lb cap

Possible solution tried as mentioned:
185/r14 Light Truck Radial - 8 ply with 1874lb cap

I'm not a tire guy, but the possible solution looks to be "up" in quality than factory stock?

the following is my opinion.

radial tire:
runs cooler
has less rolling resistance

.....in the case of the Kumho 857:
has slightly higher load capacity
has a higher speed rating
is a tire that is designed AND marketed by Kumho to be SPECIFICALLY suited to both trailer and commercial vehicle use ( see their worlrdwide website )

And so, again, my opinion, the suggested tire is an improvement in every single performance category. It's downside is that it might cost an additional $20 to $30 per tire.

EDIT: info on the Kumho 857 tire is also on the kumhousa site

[Francesca Knowles]

Is there more than one "Kumho 857", perhaps in sizes other than the 14's mentioned?

I ask because according to this link, the Kumho 857 14" radial is for trailer use only, which makes it pretty much an ST whether it says so on the sidewall or not.

It's also not a commercial tire, since it lacks the UTQG rating required for such a designation.

Francesca

[Carol H]

Originally Posted by Ice-breaker

If it was my trailer that was suffering from this issue, I would want to assure myself that the proposed solution is in fact a long-term solution.

Dave raises a VERY important point. Lots of ways to temporarily fix the issue by changing tires but for how long is that really going to be the fix? How many years of use will it be before the trailer starts to sag down as they all eventually start to do - depending on the mileage and road conditions the trailer has faced, 1 inch of additional clearance could vanish pretty fast. Then what? Trailers off warranty and your left holding the bag for a more expensive fix that perhaps should have been done originally.

My experience with trailer tires is that I would much rather use radial tires specifically designed for a trailer than for a light truck so would not be very happy customer if the solution to a problem was to use LT tires only.