Tire Clearance

I asked Bill how much clearance he had before and after switching to 15 inch tires. He gave me some great advice, and suggested I post the question here for further info. I cannot tell if I have the new 45 degree axle just by look at it. I would like to put on 15 inch tires and wheels but I don't know how much clearance is enough etc. My axle is welded to the frame and although I think I read in another thread that it was ok to grind the welds off, that seems pretty extreme. Any way, how much clearance, or how high off the ground do you all have? Any other advice on how to make the frame accomodate taller tires would be appreciated.

I'm new here and wonder what you are really gaining by going to 15 inch tires....it is the diameter you are talking about on the rim, hence you gain 1/2 inch in height--or am I missing something??

Thanks

I'm new here and wonder what you are really gaining by going to 15 inch tires....it is the diameter you are talking about on the rim, hence you gain 1/2 inch in height--or am I missing something??

There are 15" tires that are capable of carrying a lot more weight than the best 14" The 14" tires on the smaller TMs are right at the limit of their weight carrying capacity and are prone to failure due to not having any safety margin. The 15" tire will carry considerably more weight and wheels are available with the same bolt pattern as the 14" wheel. Several people have gone to 15" wheels and have not had any further tire problems.

We have the same TM and we've been trying to answer the same question. Bill's TM has a different axle and he really can't be sure if the new-for-'07, factory-lift, dexter axle provides adequate clearance for the 15 inch wheels. I e-mailed the factory and could not get a definitive answer --- only that they still recommend an additional 2 inch lift --- to the new, lifted axle --- just to be on the safe side. They also took the position that the 14 inch tires and wheels are adequate when properly maintained. But if we were to add another 2 inches to the lift --- we wouldn't have adequate garage clearance. If I remember right --- Bill's 15 inch Marathons are only 1/2 taller than the 14 inch Marathons. This was surprising but encouraging. I'd bet --- but not the price of a new set of tires and wheels --- that we'd be alright with a profile only 1/2 taller.
I already charted unfamilar territory when I was one of the first to purchase and test a Yamaha 2400 generator at elevation. I'm hoping that someone else will blaze a trail with the 15 inch wheel issue. Good Luck.

Originally Posted by [email protected]

I asked Bill how much clearance he had before and after switching to 15 inch tires. He gave me some great advice, and suggested I post the question here for further info. I cannot tell if I have the new 45 degree axle just by look at it. I would like to put on 15 inch tires and wheels but I don't know how much clearance is enough etc. My axle is welded to the frame and although I think I read in another thread that it was ok to grind the welds off, that seems pretty extreme. Any way, how much clearance, or how high off the ground do you all have? Any other advice on how to make the frame accomodate taller tires would be appreciated.

Not being certain of what degree axle you have, and not even being certain of my own (which I think is a 0 degree), maybe you can tell if you have enough clearance by where the bottom of the fender skirt comes to your wheel. I did the lift kit install, and before the fender skirt came about even with the top of the center hub. After installation, the bottom of the fender skirt now falls about 2" from the top of the wheel. I would think that if the bottom of your fender skirt is around that area or higher, you shouldn't have a problem with the 15" wheels and tires as far as foward, top, and back clearance. I have seen pictures of the newer TMs, and they look to ride much higher than mine, even with the lift kit. The closest side to side clearance for me is the the tire to the fender skirt, which is ~3/4". Beware that if the fender skirt is "bowed" in, that might need to be straightened them some. See thread:
http://www.trailmanorowners.com/foru...ead.php?t=6245

Also, this thread might help:
http://www.trailmanorowners.com/foru...ead.php?t=5586

I can post a before and after picture of my lift kit install is needed.

Chap

Thank you Bill and Chap,
To clarify --- I was hoping that someone else would remove ALL guess work by reporting that they had installed the 15 inch wheels on an '07 2720sl and they had ample clearance even under heavy loads and harsh road conditions. Mgoliver is probably hoping for the same assurance. But from what Chap shared (about before and after distances between the fender skirt and hub) I'd be inclined to say that I'd have adequate clearance --- assuming Chap has rounded fender wells --- but I'm not sure if the '03 has the same wheel wells as the '07.
And from what Bill shared --- well, I got out my flashlite and at 11:00 pm (Bill you inspired me) I bellied under the trailer to gather all the axle, bracket, and swing arm #'s I could possibly find. Since I couldn't cross reference any of them on Dexter's website (thank you Bill for providing it) --- I sent the numbers on to Dexter for clarification. It's kind of hard to tell (cause the trailer is leveled and lifted on its screw jacks) but I'd guess that I (and mogoliver) have the 22 degree axle. It's midnight now --- but after my therapy dog & I get back from the hospital tomorrow I'm going to do the frame measurements that Bill suggested.
I just wanted you both to know that I really appreciate you. Thank you for taking the time to help us make informed decisions. I love this life. Eric

Eric, I do have the round fender wells. And I had it over some right rough stuff (see avatar) with a pretty fully loaded TM on an extended trip last fall.....no indications that the 15" tires rubbed anywhere. I think the SL model weighs more than the standard, but I wouldn't think a hundred pounds or so would make a difference. My 2720 (with AC & awning) weights 3400 lbs. camping ready, but before adding water and groceries.

Chap

OK 15 Inch TMer's, I just did the measurements that Bill recommended and here's the results. Just in front of the axle (from floor to the bottom of the frame) is 13.75 inches. This is with full propane, no water, no dual Trojan batteries, and minimal overnight gear. So --- if I understand Bill correctly this is "about where he started" --- meaning that we do not have the new axle which is supposed to be the standard factory lift for '07 (but not on our '07 ???). I have only about two inches of clearance between the top of the tire and the top of the wheel well. The axle bracket is both bolted and welded to the frame so adding a lift kit is not something that I could undertake myself. Gee, I was told (from our dealer) that our unit had the new axle. I'm not sure what to think now. It looks to me like the 15 incher's can only happen if I provide (at least) a one inch lift --- which would give me about 2.20 inches of clearance with the larger tires and wheels. A 2.5 inch lift would prevent me from parking the trailer in the garage. So, it sure appears that I was wrong about having the 22 degree axle. I'm a bit sad. Any other thoughts or recommendations ? Eric

Eric, I just measured mine also, and I have about the same measurement as Bill from the frame to the ground.....17.5". And as far as the axle, the torsion arms on my unit are pretty much level with the ground with weight on it. I am not sure if this is figured as a 0 degree axle with load, or maybe a 22.5 degree axle without load....guess I need to check the dexter site.

Regardless, you will probably need to put some lift on your unit. I can still get my TM in the garage with the lift & 15" wheels....but only after I remove the electric door opener arm, and propping the door open. I will take some careful measuring on your part to see if that will work. I think Bill did a post and picture on how close his unit was.

And as far as those welds, I think I read on a post that someone had just used a grinder to remove those. My unit wasn't welded, but I had to take an inpact wrench to loosen the old bolts before I could get those puppies off.

Keep us posted.

Chap

Well go figure,
Dexter responded to my e-mail and it turns out that I do have the 22.5 degree, #10 axle. Bill & Chap, my torsion arms are also horizontal under the weight of the trailer with minimal additional load. I would have expected some kind of angularity with the 22.5 degree axles. It's beyond my present understanding --- like a lot of other things. Anyway, I will not invest in the 15 incher's until I have added about a 1.5 inch lift. A 2.5 inch lift will cause the AC to hit the garage header. I know, I know ... I can't buy a 1.5 inch lift from TM. Maybe I could hunt down some bar stock or ???

I just realized --- Bill, you said that our Dexter axles require a 3 inch clearance under full load. I do NOT believe that the 22.5 degree axle is providing that --- not even with the standard 14 inch tires from the factory --- at least not on the 2720sl's. As I said --- my existing clearance is only about two inches with only minimal gear and full propane. I set a small bar across the top of tire and measured the distance to the fender well. I wonder what the factory would say about this ???

At least Mogoliver and I have an idea of what is required. Bill, you and Chap have been great. Thanks for crawling under your rigs. We all owe ya. Eric