[TW-Brian]

This post details a mod that a couple of forum members have previously completed, most notably Dyno and Little Big Foot. All that I have done is copy selected portions of the approaches that these guys have taken and added a few of my own. I especially want to thank Little Big Foot for providing detailed answers to all of my questions about his build. Here are a couple of links that have details regarding these earlier builds.

http://tw200forum.com/forum/tw200-classifieds/6783-tw200-mutant-thingy-michigan.html

http://tw200forum.com/forum/performance-customization/9065-little-big-foots-build.html

I will try to explain what is involved this mod, and what and how I did mine in order to help anyone else who may be interested in copying what I did. Here is what I started with, a stock rear TW donor wheel. Any year TW wheel will work, they are all the same.

Since I didn’t have the required equipment, or the skills, for the machining, fabrication and welding that is required for this mod, I had to find a machinist/fabricator that I could explain this project to and who had the skills to do what I wanted done. I will call the guy that I found Mike (because that is his name ).

Before disassembling the stock wheel it is necessary to measure and record where the center of the TW rim is with respect to the axle hub. This will allow you to properly locate the trailer wheel with respect to the axle hub. It is also necessary to measure and record the position of the brake mounting flange as this will need to be removed and subsequently replaced. Next you can disassemble the stock rear wheel. I would suggest keeping the spokes and nipples to have on hand for when other forum members need a few replacement spokes. Yamaha only offers these spokes in a complete set and I have given all of mine away already.

All that you really need is the rear axle hub assembly.

Now for a little bit of terminology to help keep the following explanations straight. Let’s call the leftmost flange on the above picture the sprocket mounting flange, the inner flange will be called the small spoke flange, and the rightmost flange will be called the brake mounting flange with large outer spoke ring.

The trailer wheel that I selected is a 12 inch x 4 bolt wheel (TW-AW2024040-82171 12x4 White Steel Spoke Trailer Wheel with Pinstripe 4 Lug, 1220 Max Load from Trailer-Wheels.com - $25.69 ($36.53 with tax and shipping).

More to come…………….

 

[TW-Brian]

Here are the mods that are required to prep the axle hub.

1) Machine off the large outer spoke ring section of the brake drum mounting plate. This is not a critical operation, you just need to leave enough of the brake mounting plate to secure the brake drum to it. Mine is approximately 4.5” in diameter. The outer spoke ring section that is removed may be discarded.

2) Machine off the weld holding the brake mounting plate to the hub. Remove only as much material as is needed to remove it. Retain the brake mounting plate as it will need to be re-welded back onto the axle hub in its original position.

3) Machine off the weld holding the small spoke flange and remove the small spoke flange. Remove only as much material as is needed to remove it. This small spoke flange can be discarded.

Following are a few pictures that Mike provided showing some of the above steps.

The next step is to fabricate a new mounting plate that will be welded onto the axle hub and will hold the lug nut studs used to secure the trailer wheel. Mike ordered a round steel plate from McMaster-Carr for this. Mine currently measures approximately 0.47” thick by 5.75” in diameter. This plate needs a center hole cut in it to fit snugly over the axle hub, and four holes for the lug nut studs. Four larger holes were also drilled into this plate in a somewhat feeble attempt to reduce the weight a little bit.

This new mounting plate needs to be positioned onto the axle hub so that the center of the trailer wheel is exactly centered where the center of the stock rim was located. This mounting plate is then welded onto the axle hub on both sides of the plate and trued up to ensure that the trailer wheel will have no wobble to it.

The lug bolt studs are then pressed into position. The next step is to weld the brake mounting flange back into its original position and true it up so the that brake drum does not wobble. There is not a lot of room between the new wheel mounting plate/heads of the lug nuts studs and the brake mounting flange, but there is enough space to allow the brake drum mounting nuts to be accessed and secured.

Here are a couple of different views to show how everything goes together.

More to come……….

 

[TW-Brian]

In order for the trailer wheel to be able to be removed from the axle hub, it must be able to pass over the sprocket mounting flange. Little Big Foot accomplished this by cutting out the original bolt circle from his trailer wheel and fabricating a new mounting bolt circle with a larger center hole and welding it onto his wheel. I wanted to see if this could be avoided by notching the center opening of the trailer wheel just enough to allow the sprocket mounting flange to pass through it. Since the TW only has a whopping 13 horsepower, I did not feel that these notches would significantly compromise the structural integrity of the wheel to the point of posing a safety hazard. The pictures below illustrate what I am describing.

I couldn’t be more pleased with the way this project has turned out so far and the outstanding work that Mike has done. I am sure that there is some measurable wobble/runout on the mounted wheel, but it is certainly not detectable with my unaided eye.

The next step will be to paint the wheel and axle hub with some rattle can black satin paint and then start shopping for an ATV/UTV tire to mount up.

In case you are wondering why anyone would bother to do this, here are the benefits that I am hoping to realize with this mod:

-The ability to safely and easily mount a wide variety of ATV/UTV tires (some even DOT approved) without the danger and drama associated with mounting an ATV tire onto the stock TW rim.

-To be able to run the selected ATV/UTV tire in a tubeless manner which will allow at least the possibility of plugging a puncture in the field.

-To have at least some chance of being able to break the bead, do a repair/replacement of the tire and reseat the bead in the field, or be able to have this work done by any place that can remove and replace a car or trailer tire.

-In case you happen to be in some remote, third world location without access to the very limited selection of tires that will fit the stock TW wheel, you could probably even get by with mounting a standard car or trailer tire until you are able to source and mount a more suitable tire.

 

[joeband]

great write up brian! your constant search for mods, upgrades, and enhancements never ceases to amaze me... then you post the best write ups with progress, pitfalls and pics!
thanks!

now will your new 225 motor help push this mod?

 

[Fred]

Excellant Brian! I'm trading a good quality wheel for Mel's wobbler he rode in Moab just so I can do such a modification. Any chance Mike the machinist would like to do another?

 

[Gulfrider]

Could you use a aluminum trailer wheel for weight saving, just curious. I would think so? Good job on the fit

 

[admiral]

I am oh so tempted now!

I assume the ATV tires mount to the trailer rim without all the modification hassle to the bead of the tire and danger with high psi. to seat the bead?


Do you have and want to share the measurements or is it too early in the testing process to be sure?

 

[Fred]

If I recall correctly I read years ago that the 12" rim results more DOT tire options as well as reduced overall weight when run tubeless compared to OEM tire and wheel assembly. Since then the blossoming of the UTV industry might have changed the tire availability options significantly.

Other builds I have seen had the hybridized hub welded to the trailer rim. TW-BVrian's/Mike's design permits un-bolting of assembly which might help changing a tire with only an automotive tire change station is available w/o smaller spindle needed for motorcycle wheels.

Anyways I would jump on the opportunity to join in a group deal compared to trying to convince a local machinist to "re-invent the wheel".
Once again my hat is off to TW-Brian!.:hatsoff:

 

[Fred]

Are these too big?

 

[Fred]

To avoid nasty rubbing one might wish to go slightly smaller. These might be better.

Anyone have any good mounting suggestions?

 

[Fred]

All these ATV tires are pretty heavy compared to stock but going 12" cuts the weight and the smaller sizes might fit in stock swing arm just fine while not needing any gearing changes due to greater carcass diameter.

A 25 x 8 x 12 might be a good option.

 

[Dryden-Tdub]

You don't want them rubbing on you so slightly smaller might be better. View attachment 23431 Anyone have any good mounting suggestions?

You probably wouldn't mount them properly Fred. Send them to me and I will mount them for you



Tom

 

[Fred]

Tom, your sense of self sacrifice is admirable. Sure you could endure the possible nasty rubbing?

 

[TW-Brian]

Wow! Thanks for the comments and questions, I'll try to answer all of your questions as best I can.

First off - Fred, those look just about right .

I thought that a few of you might be interested in this mod, so I had already asked Mike if he would be interested in doing more of these. He said sure. He said that mine took him a little longer than the next ones would because he had to think about how best to do things and in what sequence. He said that it is not a difficult job and is pretty straightforward but does involve quite a few individual operations and needs care taken to center and true things up properly. He charged me $175.00 and said that is what would charge for additional wheels. I know that that is a little pricier than what I was hoping for, but I would guess that the total cost of having this done is probably pretty close to the price a new stock wheel.

I will have to talk to Mike about the logistics of building up a few of these wheels for people spread out across the country. These parts are heavy and bulky, so shipping costs will not be trivial.

Speaking of weight, the wheel, hub and brake drum assembly as shown below weighs 19 lbs. I don't have a bare stock wheel for a direct comparison, but the stock wheel with tire shown below weighs 32.6 lbs.

I have considered getting another Duro Power Grip tire so I could do a direct comparison of weight between my current Duro on the stock wheel and a Duro on the trailer wheel, but since there are so many other options available I am not sure that I will go with another Duro.

The reason that I went with the 12" wheel is that is what the other guys have used, I have also read that there is a greater selection of tires available than in the 14" size, and Little Big Foot told be that the 12" trailer rim is significantly lighter than a 14" rim (I have not confirmed this to see how significant the weight difference is).

Regarding the completed tire diameter. I am currently running a 26"(diameter)x8x14 Duro. I can also get a 26"(diameter)x9x12 Duro, so the diameter of the completed tire can remain the same even though it is on a smaller wheel (greater sidewall on the tire).

Regarding bead seating pressures, Little Big Foot said "Tire seated at 25lbs first side and 30 the other side, just pop pop".

I picked a white trailer wheel just because that seemed to be what most of the cheaper ones are. I expected that it would require some machining and I would have to paint it anyways. I had visions of getting everything back covered in weld splatter, cutting and grinding marks, etc. that would require a lot of cosmetic cleanup however the pictures I posted are just the way that I got it back from Mike - very clean with no cosmetic cleanup needed. Besides, satin black will match my Joemama swingarm and the rest of my bike's color scheme.

I do not see any reason why an aluminum trailer wheel could not be made to work. I don't know if those aluminum wheels are cast, forged or machined from billet and I do not know what detrimental impact the notching might have on these different types of aluminum wheels. I guess someone will have to be the first to give one a try.

 

[Dryden-Tdub]

Tom, your sense of self sacrifice is admirable. Sure you could endure the possible nasty rubbing?

I didn't say I would enjoy it. Just taking one "actually two" for the team.

I probably won't get it perfect the first time but I resolve to mount them as many times as it takes until it is perfect. Just the kind of guy I am.



Tom

 

[HKLBRY]

I am really liking the thought of being able to "plug" a tire without having to remove the rim and tire in the field, with the tubeless tire route.
I have been browsing ways to make a spoked rim into a tubeless rim, but this is a better way of getting that modification done. I have also been browsing the run flat foam for atv tires, there is several options.

Any thoughts on combining the atv run flat foam wedges that are now out on the market, with this trailer rim and a DOT atv tire setup?

 

[joeband]

i'd never thought of going this route, but the list of advantages certainly makes one consider it. $175 is cheaper than any rear wheels i see on eBay, all ranging from $300- 400.

 

[HKLBRY]

Can this be done with the stock length swing arm? Or is it necessary to extend the swing arm as part of running atv tires.

 

[Fred]

I have run a 26x8x14 Duro with the stock swing arm for a year w/o any issues in typical rocky sierra jeep trails. Only recently extended the swing arm due to reported fears of possibly jamming a rock between tire and swing arm. So I would say that extending the swing arm is certainly not mandatory. However I think I am enjoying the greater suspension travel and softer spring rate afforded by the 2" lengthened swing arm. I commented earlier that possibly a 12" trailer wheel conversion would allow use of smaller conflict-free ATV tires with stock swing arm, another benefit of TW-Brians inventiveness.

 

[TW-Brian]

Fred's comments are spot-on. I ran the same size Duro as Fred in the stock swingarm shown below for at least 2,000 miles without problems. As you can see, there is some evidence of paint damage on the right side which is where the pinch point occurs with ATV tires in the stock swingarm.

The pictures below illustrate the clearance on either side of the stock swingarm. I found it necessary to remove the lower chain guard bracket when I mounted the Duro. Clearance will also depend on your chain and how far rearward it will allow your axle to slide in the frame slots.