TrailManor Owner's Forum - View Single Post

**Denny_A** · 11-23-2003, 11:55 PM

I know that it is akin to committing hari-kari (sic) to jump in here - but, like a moth to the............ :P

Regarding axle and options and max weight limits, etc. Let's assume we're hauling a 2002 2720 SL. Using numbers from TM's specs, we know that:

Approx dry Wt -------- 2680 lbs
Approx Tongue Wt -- 378 lbs (2680 * 14.1%)
Approx Load Cap ----- 1394 lbs
Approx Max Gross Wt - 4074 lbs.
Max Recommended Tongue WT -- 14.1% of Max Gross = 574 lbs.

Here's the kicker. If the max allowable tongue weight is carried on the hitch WITHOUT use of weight distribution, then the load on the axle is 4074 lbs - 574 lbs = 3500 lbs. Why, it's almost like magic how that works out.

BTW, I know the tongue weight % numbers to be correct, since they came from THE TrailManor design engineer - directly in a one-on-one dialog.

Problem (as usual): If one employs a WDH (who doesn't), then some of the tongue weight is distributed back to the axle. If the set up is done properly, it will be about 1/3 of the total. So, in the 574 lb example, about 190 lbs is pushed back to the trailer - therefore onto the axle.

At this point the axle is carrying 3500 + 190 = 3690 lbs. OOPS! What's a poor owner to do.

1. Limit MGW of the trailer to 4074 - 190 = 3884 lbs. -OR-
2. Don't worry about it and just have fun.

Regarding 2, a few details regarding axle wt limits are in order. There are already several posts in this forum's archives regarding the subject.

Essentially it comes down to a difference in point of view between Dexter (axle mfr.) and TrailManor.

Dexter say that the axle is limited to 3500 lbs as evidenced by weights recorded with the tires resting on scales.

TrailManor say that, in reality, the axle and wheel assemblies, taken together, are unsprung weight, amounting to 200 lbs. Therefore, if the scale shows 3700 lbs, the axle capacity of 3500 lbs is not exceeded. You're good to go.

I neither disagree nor agree with the TM method. I do know the above interpretation of TM's position is correct, since it was communicated to me aurally by the design engineer and repeated at my request. Therefore, I am acting as a messenger, not an advocate.

Regarding 2., above, one could carry 4074 lbs whilst using a WDH, record trailer weight minus hitch load as 3700 lbs and be good to go - according to TrailManor. However, using the Dexter approach, unload 200 lbs from the axle, to be really safe.

Summary: 1. Dexter -- 3500 lbs max weight on the tires
2. TrailManor - 3700 lbs max weight on the tires.

I'll stick with the Dexter model, just to be SAFE!

Denny_A

11-23-2003, 11:55 PM	#10
Denny_A Former TM Owner Join Date: Jul 2002 Location: Greenville, WI Posts: 517	Re:Tire Margins on 2619 I know that it is akin to committing hari-kari (sic) to jump in here - but, like a moth to the............ :P Regarding axle and options and max weight limits, etc. Let's assume we're hauling a 2002 2720 SL. Using numbers from TM's specs, we know that: Approx dry Wt -------- 2680 lbs Approx Tongue Wt -- 378 lbs (2680 * 14.1%) Approx Load Cap ----- 1394 lbs Approx Max Gross Wt - 4074 lbs. Max Recommended Tongue WT -- 14.1% of Max Gross = 574 lbs. Here's the kicker. If the max allowable tongue weight is carried on the hitch WITHOUT use of weight distribution, then the load on the axle is 4074 lbs - 574 lbs = 3500 lbs. Why, it's almost like magic how that works out. BTW, I know the tongue weight % numbers to be correct, since they came from THE TrailManor design engineer - directly in a one-on-one dialog. Problem (as usual): If one employs a WDH (who doesn't), then some of the tongue weight is distributed back to the axle. If the set up is done properly, it will be about 1/3 of the total. So, in the 574 lb example, about 190 lbs is pushed back to the trailer - therefore onto the axle. At this point the axle is carrying 3500 + 190 = 3690 lbs. OOPS! What's a poor owner to do. 1. Limit MGW of the trailer to 4074 - 190 = 3884 lbs. -OR- 2. Don't worry about it and just have fun. Regarding 2, a few details regarding axle wt limits are in order. There are already several posts in this forum's archives regarding the subject. Essentially it comes down to a difference in point of view between Dexter (axle mfr.) and TrailManor. Dexter say that the axle is limited to 3500 lbs as evidenced by weights recorded with the tires resting on scales. TrailManor say that, in reality, the axle and wheel assemblies, taken together, are unsprung weight, amounting to 200 lbs. Therefore, if the scale shows 3700 lbs, the axle capacity of 3500 lbs is not exceeded. You're good to go. I neither disagree nor agree with the TM method. I do know the above interpretation of TM's position is correct, since it was communicated to me aurally by the design engineer and repeated at my request. Therefore, I am acting as a messenger, not an advocate. Regarding 2., above, one could carry 4074 lbs whilst using a WDH, record trailer weight minus hitch load as 3700 lbs and be good to go - according to TrailManor. However, using the Dexter approach, unload 200 lbs from the axle, to be really safe. Summary: 1. Dexter -- 3500 lbs max weight on the tires 2. TrailManor - 3700 lbs max weight on the tires. I'll stick with the Dexter model, just to be SAFE! Denny_A