Need help figuring trailer load capacity

[JMAC]

We've got a community sailboat, a 23' AR True Rocket centerboard sloop. I've got a spec sheet for the boat that calls out the weight at 2600 lbs. There's a trailer in town that is for sale. The manufacturer's plate is worn out. So, if I give the specs can we figure it's capacity?
It's a double axle with 12" wheels. The springs are 3 leaf and 23" long, one spring per tire. The axle beam is 2" x 2 1/2" and the wheels are about 6 1/2' apart on center and 29" apart on each side. The bulk of the frame is made of galv. 2" x 4" channel. The frame is about 5 1/2" x 12' then tapers to the tongue. Overall the trailer is in good shape, good wheels and tires, bearing buddies on 3 of 4 wheels. Is this enough info to see if it's a beefy enough trailer?

[Thorne]

Should be fine -- boats that weight are sometimes trailered on single-axle trailers.

A larger issue is brakes. Will you be trailering it over hills, or with a relatively light tow vehicle? With no brakes a heavy boat on a trailer going downhill can try to pass you on the turns...don't ask me how I know this.

[Brian Palmer]

Sounds like it may be close.

I've got a single axle trailer that is rated at 1600 lbs.
I have seen one tandem axle trailer rated at 2500 lbs, and I suspect that may be on the low end of the range for tandem axle trailers.

Check also to see what the load rating is on the tires. That may give you a clue.

Brian

[andrewe]

The spec sheet may be somewhat lower than the weight as you sail it. Having said that it does sound like it might be up to it.
A

[JMAC]

"A larger issue is brakes. Will you be trailering it over hills, or with a relatively light tow vehicle? With no brakes a heavy boat on a trailer going downhill can try to pass you on the turns...don't ask me how I know this."

Of course I have to ask, how do you know this? If we start having too much fun on the pond, I'd like to try her out in Penobscot Bay. Belfast is about 25 miles east of here.

[switters]

lets put this into perspective shall we.

The 2,400 lb camper with the single axle and 12-inch tires just went to Oregon and back to Colorado, no worries, despite some unfortunate "off-road" adventures. Towed with Xterra.

I'm guessing your boat will be about 3,500 lbs with trailer just to be conservative, which is still light for a full sized pick-up or SUV.

Said full size pick-up or SUV will have the brake capacity to tow said boat and trailer provided the driver realizes that his stopping distance has increased.

edit, Thorne addressed this already, so what are you towing with?

[ben2go]

Most common 12 inch tires are not usually spec'd to carry that much weight.Check the side wall of the tires for the weight rating.Also check air pressure.I agree with the above statement about brakes.Unless you're pulling it with a 1 ton truck or bigger, brakes are your friend.

[ishmael]

The trailer sounds adequate as to load carrying, if not exactly robust. Re-pack the bearings even though they've got bearing buddies.

The problem, as mentioned, is going to be with brakes. You're over the legal weight limit if the trailer doesn't have brakes. Retrofitting is possible, but it's not a walk in the park and often means new axles. Not particularly cheap. I looked into this a few years back and finally said, I'm just going to live with what I've got. But my rig was just a smidgen over, if at all(working by guess and by god, but I wanted to be legal) This one is gonna be way over.

Just an idea, but how about finding a yard with a ramp, or someplace else near a ramp?

[JMAC]

We've been sailing on Unity Pond, big enough for a nice afternoon sail without running out of room, throw in a couple of swimming spots and a picnic and it's a great way to spend a day. So far I've borrowed a friend's trailer but it's a 4 man pain to get it under and out from under twice a year. The boat winters next to the lake, but about 3 flat miles from the launch. I looked at the trailer again today, the guy's asking a reasonable price, but I'm used to getting deals....I have another line of reasoning about this, but I'm heading into town to see my sweetie!

[Woxbox]

I agree, this trailer should do the job just fine. One other caution -- examine those tires. Most used trailers have old tires that aren't worn down in the tread, but are so dried out that the rubber is disintegrating. I've exploded a couple of old tires on the highway -- they get hot and then "bang" -- you have globs of melted rubber all over your boat.

[Gold Rock]

Actually, you can determine the axle rating, to a point, accurately. To wit: pull a hub off the trailer. Remove the inner and outer bearing. You'll have to remove the inner seal, and may damage it. There's usually a number on the seal, too, so make note of it. It's what you'll use to make the I.D. to replace it. The inner/outer bearings will have numbers on them. It's the combination of these two bearings that denotes the hub's load capacity. Most commercially built trailers use spindle/hub combinations that are of a select standard. The most common small trailer combinations are as follows; inner/outer (I/O) no.s 44643/44643 or 44649/44649 usually rate at 1250 lb. per spindle; I/O #s 68149/44649 rate at 1750 lb./spndl. There are many more, not to mention some variations of the groups mentioned above, but yours is most likely one of the first two. Since you're running 12" wheels, it's almost certain. The exception in your case is if the hub groups were imported from Asia. Unlikely, but possible. Then you could have groups whose rating I could not determine, but would likely be less than 1250#/spdl. Also, back when I was peddling small trailer running gear for a living, there were certain standards that applied to all over-the-highway trailers, amongst which were these requirements - if the trailer had more than one axle, at least one axle must have brakes, this was a minimum and some states, like Washington for instance, required brakes on all axles. Also, the gross trailer weight rating (gtwr), which is the total of the load and the trailer itself, could not exceed a certain percentage of the tow vehicle weight. I seem to recall 55% or 65%, but you'd have to check for yourself. The point is, if you've got, say 3000 lb. of gtwr, expect to get ticketed if you're pulled over with it behind your subcompact. Just grist for thought, you understand. Gee, I never thought I'd dust off this load of arcana again, but there you go.

Chuck

[Horace]

Does your state have licensing requirements for on-road trailers? If so, does the trailer's title have the gross/empty weight listed? That might save a lot of guess-work.

[Thorne]

I've towed a lot of small boats with a variety of vehicles. Most extreme / foolish was towing my old San Juan 21, which at the time probably weighed 2000lbs, with a 1969 VW Westfalia pop-top camper van.

I could get it moving right along on the flats after a block or so, didn't attempt any hills, but had to collect all the idle hands at the launch ramp to help push the van up the ramp when pulling the boat out of the water.

;0 )

My experience towing in the mountains was with several Nissan 4x4 mini-trucks and a cr*ppy Ford Bronco II. By that time the boat was set up for short cruises and weighed a good 2500lbs, and came close to outweighing the tow vehicles at times.

Coming back from Lake Tahoe, the SJ 21 really really wanted to pass me on the curves on I-80 when going downhill at 60mph.




"A larger issue is brakes. Will you be trailering it over hills, or with a relatively light tow vehicle? With no brakes a heavy boat on a trailer going downhill can try to pass you on the turns...don't ask me how I know this."

Of course I have to ask, how do you know this? If we start having too much fun on the pond, I'd like to try her out in Penobscot Bay. Belfast is about 25 miles east of here.

[ishmael]

Lot's of good thoughts, none of which should be taken as gospel. Check it out, make your own decisions.

One other thought: Is the trailer made of galvanized or painted steel? While not an absolute measure of quality of bearings, it is true that manufacturers who took the time and expense to galvanize matters did tend to put stronger/better bearings in the wheels.

Good luck.

[The Bigfella]

There's another issue you may need to address - and that is weight distribution. You should be aiming IIRC for about 75 - 90lbs on the ball when the trailer is loaded.

I'm building a trailer at the moment - and it is for two boats and to get the ball weight right, we have to move the spare trailer wheel from the front to the rear for the different boats - and it does make a difference.

As for axles - my 40mm square axle - a poofteenth over 1 1/2" square - solid axle is rated at 2200lbs. My springs are 5 leaf, 8mm thick leaves (that makes a difference - some are thinner, narrower, etc) and are also rated at 2200lbs.

Back to weight - here, it is a legal requirement to have brakes if the gross weight of the trailer/load combo is over 750kg - ie 1,650lbs - half of what you are talking about. For me to modify an axle and install brakes on one axle on the trailer I'm building at the moment was going to be about $1000 - $1500.

This trailer incidentally - will cost me over $10,000 by the time its finished...

http://i240.photobucket.com/albums/ff112/igatenby/f2-1.jpg

[Gold Rock]

Rule of thumb on tounge weight for ball type couplings is 10-15% gtw on the tounge (ball).

[The Bigfella]

Rule of thumb on tounge weight for ball type couplings is 10-15% gtw on the tounge (ball).

That sounds about right. When we took the trailer down to the river to bring home one of the boats I will be carrying on it - we had negative weight on the ball - it was tail heavy. We moved the axle back 12" to cure that. These things tend to be a bit more difficult to do with second hand trailers...

Incidentally - I had a trailer towing incident many (like about 30) years back. I'd bought a spare old Jaguar and was towing it up to the farm on a hired dual axle car trailer - behind my bosses car. The Jag had no engine in it, so I guess the trailer was tail heavy - I was going down a long reasonably shallow hill at 60mph and the trailer got a sway up......

I knew that the theory for a sway was to snap the pedal to the metal and pull the trailer back into line. 30 years back was the 'orrible days of pollution controls on cars that killed power - the bosses poor old Ford Wagon, with its asthmatic 250 cube six - didn't have it in it to snap the sway out - all I did was get about 5 mph faster and the sway was getting worse.

I was fighting to keep the car on the road and slow down gradually when a car came the other way - fortunately I had two lanes to work with (one going my way and two going his way) and he was over in the third lane. In order to miss him, I had to reef on the wheel - which jack- knifed the trailer. I shuddered to a halt.

Jack-knifing had snapped the boot open and there were old Jag parts all over the highway that I had to go and pick up. The Jag was chained on - but had still swayed enough on the trailer to ding the sill panels on the side of the trailer. A brand new battery in the back of the bosses car had tipped over - which I discovered a half hour later in the next town - battery acid everywhere...

The point of telling this rather embarassing tale - don't muck around with "near enough is good enough" with trailers. I was lucky that I didn't kill myself and whoever was going the other way that night. Almost certainly due to weight bias on the trailer.

Three or four years back I had another incident with a boat trailer - a guy going the other way hadn't tied his boat down securely and it came off his trailer - I hit it head on. :eek:

[JMAC]

So my other line of reasoning about the trailer, which could be faulty, is that come Spring it could be that boats and trailers might be going for a song if our economic downturn is still turning down. I like the thought of having a stout enough trailer with brakes. I don't mind so much reading about other people's trailer horror stories, but I don't care to have any of my own....although there was that moment on I-95 with the load of lumber a few years back...

[Gold Rock]

About 40 years ago, we were towing a Y-Flyer to a regatta on the Mississippi river in Illinois. Very light eighteen foot scow being towed behind a massive Chevy Caprice. As we were tooling down an arrow straight farm road through the corn fields, my father was looking up out his window and asked us, "you guys hear that jet?" We did, as a matter of fact. "It's been over us for a long time and I can't see it," says Pop. This was in the Sixties when low flying jets and sonic booms were the norm. Huh. Then Pop looks in the rear view mirror and says something akin to S@#T. I paraphrase. His glance revealed our trailer canted decidedly to port. We pull over and whaddaya know? No driver side wheel. At all. One bare steel hub with it's five empty studs was all that was left on the end of the axle. The road we were on was straight and flat and bordered on either side with wire fencing, so we uncoupled the trailer and started backtracking down the road to see if we could find the thing. Easy enough to do; we just followed the still (nearly) smoking trench the hub had left in the tarmac. Sure enough, the groove stopped about a mile back and, to our amazement, there was the wheel leaning up against the fence on the side of the road. Not only that, all five lug nuts were still inside the hubcap which had not popped off the wheel. Good karma.

[Thorne]

More common on boat trailers is having the bearings completely burn up, often dropping the hub and wheel off the spindle/axle at speed. Not fun.

I had a small utility trailer do this at 70mph while passing a lorry on the M5 near Tewksbury in the UK. Luckily the wheel that fell off was on the outside of the motorway, as after I pulled over, the tire and wheel passed me hopping about 20 ft. in the air each time -- and landed in a field nearby. If it had been the other wheel it would have hopped into oncoming traffic...

Moral of the story? Always check the fit and tightness of the hub and wheels on the spindle -==- grab the wheel and shake it a bit to see if there is too much slop. This is not a check for the lug nut problem as described above, but much harder to test visually -- you gotta actually pull on the wheel.

[The Bigfella]

Use bearing buddies - and make sure you don't have Chinese wheel bearings.

[Tylerdurden]

Chances are your trailer is fine. Its the axles and spindles that need to be considered. If you dimension out the axles and compare them with the Northern tool catalog it will give you a good answer. The real issue is how its sprung as a stiff trailer will damage what you are hauling.
Too loose just as bad as it will self destruct.

If you can wait some trailers and accessories will be out in droves soon enough. I would post a want on craigslist as just before Christmas everyone wants to sell.

Also on every used trailer pull the hubs before purchase. Don't want to get stuck with someone elses spun bearing damage. Seen it too many times.

[JMAC]

We did jack up under each wheel and spun them and checked for slop. Everything seems good. In my cheapskate mind as I drove past this trailer for the past 2 years is that I'd like to get it for $400. When we asked about it last weekend, the guy said $1000 firm. He calls the next day and said he'd take $750. We looked again yesterday without making an offer, but told him I had to get the capacity thing figured out. I think $750 is in the realm of fairness, but the boat needs some other things like a sail cover for a 14' boom and a jib to call it's own instead of the too small one from my Rhodes 18. The folks involved with the boat have chipped in and we almost have that amount. I think that I'll offer $600 in spite of his sob story.

[JMAC]

....unless Bigfella will make one for us....

[The Bigfella]

....unless Bigfella will make one for us....

A simple one isn't that hard to make - but you won't even buy the steel for $700.

Seriously - the biggest issue you will face - assuming overall integrity of the trailer is OK - is the weight distribution one. It you need to start making structural alterations for rollers and bunks - you will encounter rust protection issues - but that can be countered at varying cost and effectiveness levels.