Project: Build trailer to haul the GL1200 ASPY

[DaveKamp]

Now, the other thing I did today, is I removed four wheels from the trailer of my bigger boat... it's a 22ft SeaRay cuddy cabin, and for a variety of reasons I haven't had it out of the barn in some time, and all four tires were shot, so I removed them, and slipped in a PAIR of 14' wheel/tire combinations I salvaged from somewhere... and I took the two 15" rims from this donor trailer and put 'em on the back axle of the boat trailer, just so there was something other than hubs to roll on. I'll push the boat back into the barn, but that's a different project for a different forum.

Anyway, the 22's ShoreLander had a quartet of 185/80R13 passenger tires (bad choice for a rather heavy boat), and I'll admit, when I backed the trailer into the barn last, those tires were in bad shape. They held air, but they didn't now. I took the shot tires and rims to my manual tire machine, and stripped the tires off.

With the offset 3500lb axle I'll be using, the 5-on-4.5" bolt pattern is common to many size wheels... 16,15,14,13, 12, and even 10 and 8" trailer wheels can be found with this pattern, but this axle is fitted with electric brakes. I test-fitted a 13" wheel, and was very pleased to find that the wheel easily cleared the electric brakes. The 175/80R13 tire height comes in around 24"... that means the center of the hub will be 12" (unladen) off the ground. Combine that with the axle's drop, spring height, and the fact that the 'backbone' is LOWER than the suspension frame height, my tray height SHOULD be pretty darned low. It means I'll have to sacrifice ground clearance for debris, but I can accept that penalty. Now, I don't know wether my drop axle's beam will have enough clearance from the center channel, but... I'll blow up that bridge when I get to it. Right now, I KNOW that having a 13" tire, healthy axle offset, and low tray means the bike's CG will be very low on the trailer, so it should be incredibly stable for carefree towing over long distances.

The 13" trailer tire choices are plentiful, and they're EASILY available in load range B, C, and D. With the bike and trailer weight, I'll probalby be fine at load range B, but given the choice of a D tire, I'll certainly accept the heavier carcass of a D tire, if for nothing more than brute force durability in unpleasant road circumstances. I will be carrying TWO spare tires, and appropriate equipment for rapid changes, but I hope to not need them on the road.

 

[DaveKamp]

Today's progress started with a pair of tires from Craigslist... ST175-80D13's that came to me on 4-hole car rims for $10 each. basically no road wear, they're Kendas, probably 4 years old, load range C. I won't run these as my long-distance tire, but for now, they get me proper elevation and a platform to work from. I've got two more rims from the ShoreLander that'll get new 'shoes' when the time comes.

Here they are, mounted on the drop axle, I'm eyeball-gauging it a bit.

 

[DaveKamp]

Now for the bigger bite:

It was loosely clamped together last night. Today, I'm winding up the lightning-box to tack it together, starting by lining up and squaring the back, and lightly tacking the top sides, then same for the front, then middle.

Once the ends were tacked at top, I pulled the middle in snug with strap, then pushed everything home, and continued tacking.

That left everything basically where-it-should-be, and alignment is actually pretty darned good, considering...

 

[DaveKamp]

Of course, it's easier to get a good bead on stuff when the positioning is good, so I flipped it to get the bottom and sides glued in right. I even picked it up and hung it from the forklift to make the vertical seams horizontal-orientation.

And yeah, I did this with 7018 DC stick, but it's just to make it solid enough to work on. I'll be doing some gusseting and finishwork with MIG later.

But for now, it's holding together fine enough to work with axle dimension and positioning, measurements and calculations.

 

[DaveKamp]

With the frame top level and at 18", here's the clearance to drop axle. The back end of the trailer is kinda high, but once the axle position is set, the tilt will NOT be considerable in order to direct-load the GL1200.

You may note that there's not enough clearance for suspension travel, and you're right. You may ask "What the heck are you thinking?"

And I'm not gonna tell you... you'll just hafta wait and see.

And yes, the axle is bent- right square in the middle, and it's supposed to be... that's what determines tire camber. Obviously, when I narrow this axle, that will be affected, but that's not important right now. (Airplane!)

 

[saganaga]

DaveKamp » Yesterday, 11:54 pm[/url]":fr8do6rk]
Okay, had some absence - out of town on vacation, doing some bicycle riding, canoeing, and wandering around the 'driftless' area of northeast Iowa, southeast Minnesota, and western Wisconsin. Now I'm back, and at it again...

Ever gone to the BWCA or Quetico?

 

[DaveKamp]

[/quote]Ever gone to the BWCA or Quetico?[/quote]

Nearest I've been, was Ely, Mn, and the Superior coast, down the US side... Ann and I took the kids up there six-seven years ago. I got sent over to Sault Ste. Marie, Ontario on biz three years ago, boss made me fly from home, through Chicago, then Toronto. Most recent over the border was to Ste. Agathe, Manitoba, and it was January of last year... stupid cold temperatures for my outside work. I drove that one, in an empty, plain (non-service) truck, with no tools. Boss didn't want me to, thought I'd get turned around at the border (NAFTA right?) but went fine, and I'm glad... I would have been well-frozen if I had to limit myself to carry-ons... my cold weather coveralls, boots, coat, gloves, hat, etc., would've filled one big bag all on it's own.

One of the reasons I'm building this trailer, is so that if I get sent to say... Moose Jaw... during the summer or fall, I can drive my company truck to someplace relatively close to the border, park it, toss my overnight bag and computer bag on the bike, and ride across the border to my jobsite. All i do when I'm up there is supervise, make sure it's all done to our standards, inspect everything, make sure all our contractors get paid, etc., and then get a pile of signatures... then do a little touring, see the places that my company truck can't easily go, then back to my truck, and drive home...

 

[DaveKamp]

Latest update on the trailer project:

Today, I did absolutely NOTHING....

I had Jury duty in the morning, and mowed the weeds in the south lot, and assembled some shelf racking in the pole barn.

But I thought about the trailer project, so it wasn't totally absolutely nothing. Sometimes projects need 'think' time, and other times, they need 'do' time. Bein's that it's a courthouse, we're not allowed to carry cellphones, pocketknives, mace, tazers, or firearms, that kinda limits certain aspects of accomplishment during the 'waiting time'... but they had to carry it further, by disallowing pencils, pens, calculators, slide-rules, protractors and compasses, trammels, dividers, and trig tables...

Because they're considered...

Weapons of Math Instruction... :smilie_happy:

 

[joedrum]

Wow jury duty and get treated like your the criminal and no pay sheesh

 

[saganaga]

DaveKamp » Yesterday, 10:28 pm[/url]":23wa54v9]

Ever gone to the BWCA or Quetico?

Nearest I've been, was Ely, Mn, and the Superior coast, down the US side... Ann and I took the kids up there six-seven years ago. I got sent over to Sault Ste. Marie, Ontario on biz three years ago, boss made me fly from home, through Chicago, then Toronto. Most recent over the border was to Ste. Agathe, Manitoba, and it was January of last year... stupid cold temperatures for my outside work. I drove that one, in an empty, plain (non-service) truck, with no tools. Boss didn't want me to, thought I'd get turned around at the border (NAFTA right?) but went fine, and I'm glad... I would have been well-frozen if I had to limit myself to carry-ons... my cold weather coveralls, boots, coat, gloves, hat, etc., would've filled one big bag all on it's own.

BWCA is really nice for canoe camping. A little crowded, especially in the popular spots, but not too bad. Not a bad spot for trying out the hobby and there's plenty of outfitters for gear rentals. Plus Hwy 61 and the Gunflint Trail is great for motorcycles.

Btw, and I probably don't have to tell you this, but if your job requires you going to Canada as an American, never get a DUI. Canada won't let you in, ever, if you have a DUI conviction in the US.

 

[DaveKamp]

Btw, and I probably don't have to tell you this, but if your job requires you going to Canada as an American, never get a DUI. Canada won't let you in, ever, if you have a DUI conviction in the US.

Right on! Nope, you certainly don't... first, because I don't drink (I'm crazy enough), and second... because I'm usually sent there at least once a year. The 7 other guys that share my job description go, too... but I'm frequently sent towards the east parce-que Je parle Francais... and my Canadian is pretty good too, eh! Don't worry, I'm trying to maintain my girlish figure, so I won't eat all the poutine.

Back when I taught passenger rail equipment, I made three trips of several months' each to Calgary... and when I told people I was from down south, everyone thought I was from Lethbridge.
:hihihi:

 

[mcgovern61]

Because they're considered...

Weapons of Math Instruction... :smilie_happy:

Should have seen that coming......... :smilie_happy: :mrgreen:

At the start of the thread, I would love to see if you have any pictures of the modified GN400. That was my first bike back in '81.

 

[DaveKamp]

Hi Gerry!

I KNOW I've got pix of it in my project files from oh... a decade-and-something ago... I'll dig 'em out. It's in the barn right now, dirty, and the fuel tank is off (needs some repair to the petcock area), but I kicked it with some spray lube a month ago and it lit right up. I picked the GN on account of big single carb is harder to gunk up than a pair or quartet of smaller ones...

But the bad part, is it's an ungodly difficult task to adjust... Just walk into a motorcycle shop and ask 'em for a set of sync gauges for a 400cc single!!!

 

[DaveKamp]

Okay, so I made a little progress tonight... I needed to do some measuring and proving.

In order to make this thing work, I need to determine how it's gonna actually load and unload. I need to know where the bike's center of gravity is, with respect to it's front and rear wheels, so that when I drive on, it won't 'tip' to level until the bike is all the way on... as that'll determine where my axle is best positioned. This, along with my tray height above ground, identifies what the inclination angle is when I'm loading.

So I started by laying the chassis in the paved portion of driveway, placing a piece of plastic pipe under it, and driving on... and then off, relocating the pipe, and back on, 'till I finally accomplished a teter at the balance point. I determined that the center of gravity for the GL1200, with me on it, was darned near directly above the footpegs. I would've thought a little farther forward, but clearly not.

 

[DaveKamp]

I also determined that the clearance between top of the channel, and underside of the bike is correct. Notice that I've got a 2x6 in the bottom of the tray- that's intentional. I don't want the tires to be climbing in and out directly on the steel- I expected to have something in the bottom of the channel, for a variety of reasons... and it worked out perfectly. When done, I'll actually have the filler, and the entrance of the ramp steel, tapered upwards for a graceful, safe entrance.

Notice the position of the siderails now- that's perfect width for feet. I WILL be filling in the space so that feet can go anywhere, but I know that I won't need to have any footspace FURTHER than edges now.

Also look at where the engine case guards and front wheel are... as well as rear tire. I don't think I could've gotten any luckier in terms of fitment guessing.

 

[DaveKamp]

Now for some measurements... I carried the frame back over to the welding area, flipped it over, and placed the axle under it for some in-situ comparisons... as well as some other necessary measurements.

First... the diameter of the mounted 175/80D13 is 25"... that means centerline from spindle to ground is 12.5".

Offset of the axle places CENTER of the axle tube 8.5" above the ground.

From the wheel tray edge to center of the leaf spring is nominally about 24"... 30" to the inside edge of tire tread, and 35" to the outside edge of tire tread. Since this axle is substantially wider than the trailer chassis, I WILL be shortening it... however...

If I just shorten the axle, I'll have to leave some 'arch' in the middle to yield the proper toe-in of the tires. that arch means that the axle, at center, will be higher than 8.5" above the ground. Add another several inches for suspension travel, and the tray height will be pretty darned high. What to do?

 

[DaveKamp]

Oh, and by the way, the axle tube's circumference is around 7.5", or a little bigger. Divide that by Pi and you'll see it's a 2.5" axle tube.

And here's a picture of the axle and chassis flipped, roughly in position on one side for eyeballing, but don't let the picture fool you, those spring hangars have a LONG way to go before they're touching the frame rails...

Now... I won't be directly welding those hangers to the frame... Instead, they'll be welded to pieces of angle form the leftover section you see in background... which will be, in turn, bolted to the frame rails. This adds strength, and removes the Heat Affected Zone from thinner frame rail material.

But the short of it, is that when I get the springs and axles mounted, that darned backbone is going to be RIGHT where my axle needs to pass through... so take your guesses on what my solution will be... :mischief:

 

[mcgovern61]

opcorn:

 

[pidjones]

Pivot a hinged axle from the backbone on each side?

I measured the pivot point for my GL1000 the same way, with similar findings. I moved the bike forward from that to put weight on the hitch ~50 lbs loaded. So, I can move it by hand loaded if necessary. But, I load with a ramp so didn't worry about tilt. Yours is looking good and built like a tank. You've probably got it in the plans, but let me suggest a plate for the side stand to rest on when loading/unloading, and something to hold the bike from rolling backwards if you are forced to load/unload on an incline. My sidestand lands on my walk board, and adding a 2.5" angle iron hump to the rail gives a good hold from rolling back, yet is easy to pull it over when unloading. Mine is just for hauling to shows within about 100 miles (although I used it to get my '79 ~200 miles away) pulled by an S-10. Yours looks designed to easily handle 500 mile days behind a good tow vehicle.

 

[DaveKamp]

Pivot a hinged axle from the backbone on each side?

Hah! Jones- you're like flies on stink! Yes... Swing Axle Suspension. I'll post a diagram that I was working on earlier today that'll illustrate the geometry and math, but it's not totally settled, I'm still pondering some of the angles, and frankly, I may wind up making it so that the geometry is somewhat adjustable so that I can tweak it once the bike is on, and I've had a chance to road-test it a bit.

let me suggest a plate for the side stand to rest on when loading/unloading, and something to hold the bike from rolling backwards if you are forced to load/unload on an incline.

Well, it's probably difficult to see, but once the bike is on the trailer, there's not enough side clearance to deploy either the side or centerstand. It will actually be rather difficult to tip it over, as the engine case guards will be close to the deck. Once the bike is in the chocked position, it will lock into fixtures that will hold it by the case guards, wheels, and (eventually) trailer hitch. I intend to make it so that when I ride on, it goes up the ramp, once fully on the trailer, proceed forward, the trailer tilts forward, locks in, and retains the bike very securely on it's own. To unload, I get on the bike, release the latches, roll back slowly, the trailer tilts back, and I walk it off backwards, and ride away.

Yours looks designed to easily handle 500 mile days behind a good tow vehicle.

Yeah, when I go on road assignments, I draw my day limit at about 750 miles in one day. If I'm doing multiple days, I'll generally hang it up after about 650 miles... and if it's a three-day, around 500... but it depends on where I'm departing from, what I have to pass through, and the weather and traffic circumstances I anticipate from my departure time. Regardless of circumstance, I want this thing to be tough-as-nails, and suitable for all weather circumstances, including snow and ice... because I very well may be driving from Iowa in January, to San Antonio, or Jacksonville, or Kingman... and come back a week and a half later. Nothing helps beat the cold winter blues by getting a warm assignment down south, and having the motorcycle along. arty: