Replacement sub frame fuel tank is in the works!!!!

tazer said:

Could you not fit something the same width as the muffler in this spot??
A tool container would not need to be that big 2.5" x 3"x 8-10"long would be enough.

Steve

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Hi Steve,

The dimensions look small, but, if you pull the shock and lift the rear wheel up to where it would be under full compression, and take into account the chain whip, I think you would find it is a very close call.

The other problem with "hanging" a tool box there is the strength that would be required to hold said tool box on. If you were to put mounting holes there they would have to be done with some sort of metal insert. Secondly, the torque that would be exerted on the subframe by weight hanging so far from the attachment point would be great, not to mention the vibration.

Don't get me wrong, it's a good idea, I just don't think it is going to happen.

As far as the fill hole goes........ We put it in a location that would be as convenient as possible, and where the best possible mounting procedure would work. There is not much room under the seat to do much of anything except for the vent line. As I mentioned in the post above, we are using an aluminum insert in the tank that a plastic cap will thread into. This way, if someone were to overtighten the cap, the only threads that are going to strip are going to be the ones on the cap and not the ones in your $400 fuel tank. Further, we also decided to go with a NPT female type of filling hole to keep the size of the fill cap as small as possible.

If one was to mount the fill cap into an area further back on the subframe there would not be room for this metallic insert in the molding process. I appreciate Gazza's suggestion in the fill cap location to get the maximum fuel fill as quickly as possible. We gave this, and the other design criteria of our product A LOT of thought for the pro's and con's of each idea. John Wiser of 70 Degree Racing goes way back in mechanical design, and is a great rider as well, and he has had a lot of great input to our design process and has fetted out a lot of the details, both good and bad.

One of the things that was considered when we were designing our tank was the guy who is dual sporting his bike, or is just on a long ride and pops out into the world just to get gas at a filling station. When he puts his bike on the side side stand, the sub tank fill hole will be on the "up hill" side of the bike and will allow a great deal of the sub tank to be filled before refitting the cap. Then fill the main tank with the bike up right, and the main tank will gravity fill the small remaining space in the sub tank in a very short time, then just top off the main tank with that small amount of fuel if you need to get that much into the tanks.

So basically we tried to combine the needs of as many riders as possible into our design and we feel that we have a great product coming along here.The only way that anyone will know you even have that extra gas tank will be b/c of the fill cap and our logo! The picture I added here is just a photo shop version and not the real thing. But we will have something like this on our tank.

I'm expecting to be out at the molders next week to make any final tweeks to the model and then the Aluminum mold will be made off of the model as I previously described. We will then make a few tanks to make sure they are good all the way around and give them a good thrashing to find any possible problems and then start the production run. We can produce 100 tanks a week so meeting the demand quickly should not be a problem.

Greetings all,

Here’s the latest and greatest on the 70 Degree Racing subframe tank, as of 02-24-10.

I was out at the molders on Thursday 2-18-10 to hopefully iron out the final details of the model so it could get sent off to the female shop, and then on to the foundry.

The molder had given the model project over from Tom to another model maker, Paul and I was advised of this before arriving. As usual I brought my bike and my scissor stand to make disassembly and assembly of my bike easier, as well as being able to use my bike as the mule to fit the model to.

When I had left last time it was understood that one of the sub frames we had provided was going to be cut up and the inserts removed and sent out to be copied and inserts produced to be used in our tank. Upon my arrival this time I found that had not been done. After taking the rear clip off of my bike to make ready for Paul to do his fit test for the model, I was looking for something to do and ended up cutting all of the inserts out of one of the sub frames provided to the molder after it had been cut up by Tom. I also found out that the molder, who had originally said that he could have the inserts made was unable to do so, and I am currently having these hard mounting point inserts made.





These are the inserts from inside the sub frame. The top insert in the picture is from the right rear of the sub frame and takes the vertical 8x26mm bolt (this is the one we had to redesign-see below). Starting on the bottom row left side, the first two are the bottom hard points, one for the left and one for the right, the wider one is the upper hard point from the lower left side, and the other two are the muffler hanger inserts.



It was around this time that Izzy, the mold maker came over to express concern over how one of the stock inserts protruded from the sub frame as this could cause a leak point to occur during the actual tank making process. This is the left rear vertical mouting point, from the outside, and the second picture is looking at it from the inside. The problem is the bare aluminum sticking out of the plastic, as this helps to create a path the "could" allow gasses that occur during the molding process between the mold and the plastic being molded to run down along the side of the insert and make a pin hole. This will be aleviated by cutting down the insert on the top, lengthening the 8mm thread section downward into the unused 6mm thread section to create a flat surface on the top. We will include a longer 8mm bolt and a crush collar to take up this space between the bottom of the horizontal sub frame truss, and the sub frame itself.





I have to say that this became quite an undertaking to engineer how we were going to solve this problem. Izzy had several suggestions, as well as Tom, however, each of their suggestions required the purchaser to make modifications to the horizontal sub frame or sub frame second part as it is referred to in the parts book.

This is NOT an option that we at 70 Degree Racing liked. We want to produce a replacement sub frame/ gas tank that is a bolt on affair only.

I spent the next several hours trying to figure out how to utilize the space that is available, and modify the insert to make the sub tank be a bolt on affair, yet make it so that there would not be any leaking concerns as expressed by the mold maker. In the end I was able to figure out a way to have the cake and eat it too.

While all this was going on, Tom and Paul was locating and drilling the lower hard mounting points on the model.





Late in the day the model was finally ready to place on my bike to check the fit of the lower three hard mounting points, and the hard mounting point in the top back of the model where the sub frame bolts to the sub frame second part, or the vertical 8X26mm bolts all the way in the back of the sub frame second part. While this may seem somewhat straight forward it is not, the model itself must be “plussed up” to allow for the shrinkage that occurs during the tank making process. IE the XLPE plastic shrinks inside the mold as it cools. And when one considers all the different directions in which the XLPE will be shrinking in relationship to these top two bolts in the back, and the effect this shrinking will have on the overall placement of the tank…….well you get the picture. Anyway, once we got the model mounted onto my frame, it was apparent that Paul had got the top rear mounting points right on the money.

















These, and the rest of the hard mounting points will be finalized in mold itself after the first tank is produced which will not have any of the screw or bolt holes in it. This is to allow for proper placement of the screw holes and bolt holes, regardless of the calculated shrink that will occur. This is the same process that all tank or plastic molders utilize to ensure proper placement of the mounting hardware.

To say that this tank is more complex to produce that a standard oversize gas tank is an understatement. The molder had based his original delivery time for our tank using a tried and true schedule, as well as the inserts not having been cut out and duplicated, long story short we are about a month behind the schedule that we originally thought we would have as far as delivery goes. So at this point we are thinking that the end of March will be when we start to get delivery of our tanks. I know that I was bummed to figure this out, and I’m sure that all of you who are wanting these tanks are too. However, progress is being made, and the 12 hours that I spent at the molders on this day was not wasted, as there was some other fine tuning of the model that needed to be done as well as all of the aforementioned items.

All of the other associated parts for the sub tank are in our possession, such as the quick disconnects and adapter plates, and now we are just waiting to get the tank mold done.

About all I can say at this point is to please be patient, progress is being made, and we are doing everything we can to get these tanks to market. I know I could have used one the other day when I was out riding as I was getting really close to having to bum some fuel from my buddy on the way back to the truck.

I have included several pictures from this latest trip to the molder, and as you can see things are taking shape.

Thanks Dale E O!

Thanks 06! I have to say it's more than a little frustrating to not be making faster progress, but the devil is in the details as they say. In making this post I also just realized another area that can be pushed out to get another 2 or 3 tenths of fuel so I guess that's the silver lining eh?

HSBcrazy said:

Dale,
Looks as though you are putting a great effort into this tank and I will be interested in one possibly. I haven't rode the 570 enough to know how the stock fuel capacity will be for our style of riding.
I would like to comment on a few things that have my concerns. I removed a bolt from one of my shrourds to install the cooling fan and the insert began to spin in the tank. I was very upset that this would happen on a new $10,000 dollar bike. I proceded to remove the bolt and somewhat saved the insert and I believe it will be fine with some delicate hands whenever removed again. I removed all of the bolts carefully and chased the threads on both the inserts and the bolts and ant-siezed all.
My point being here is the inserts that you have pictured look as if they could possibly not have enough prominant rough built onto them to be conducive to torque in a polypropylene type compound. We are designing that mud cover for circle track dirt cars and they have some inserts that are molded into them also. There are many suppliers of these type fastener inserts and allot of different ways to install. Some are installed after mold and maybe help with that possible gas leak that could occure. I'm a little niave about that department but thought I would pass on some info for thought. If you are interested I will look into the suppliers that I have ran across that supply these inserts that have more protrusion to be better for the softer plastic.
Hope I can help, Dana Young, Western Fabrication Specialties

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Hi Dana,

Thanks for your input!!!

To address one of your concerns, our tank, or sub frame is made from the same material that the original main tank is made from and that is XLPE or cross linked poly ethylene, which is much stronger than poloy propylene.

The insert that spun in your tank has happened to others as well. If I am not mistaken, it is a round insert with a slotted or knurled surface, no? On the 2009 bikes the shroud bolts that go into the tank are the large wood screw type fasteners, which work great as long as one does not overtighten them.

All of the rotational torque taking inserts in the sub frame have large flats on them which provide a much larger area for the torque forces to be spread out on. The exception here is the round inserts which do not take rotational torque, rather, they take radial and to some extent lateral torque, therefore they do not need a flat to hold them from turning, just large flanges to support those stresses for which they are designed.

The only spinning problems we had on the 2009's was the center sub frame second part 8mm bolts that go into the aluminum bar that passes through the top part of the tank. This problem was solved by just using a liberal coating of anti seize on the not only the bolt threads but on the angled surface of the bolt face.

All of our inserts, including the vent line and the fuel connection will be cast into the molded tank when it is made. We decided on this course of action for a couple of reasons, one being that these would not need to be installed or removed thereby removing any possibility of these inserts spinning in the plastic.

It is a shame that some folks are having these problems with the 2010 model shroud inserts. And you have done what needs to be done, clean up the threads and apply a liberal coating of anti seize compound and don't over tighten them.

Dale

Busa10 said:

Hey Dale, So are you estimating the capacity still to be around 1.1 gallons?

Thanks,
Ron

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If one stands the sub frame on it's tail and fills it up with water it holds 1.65 gallons. We have increased that area by about 3 tenths at least by using the triangular area that was hollow where the grab handles are, so in theory the total capacity could be as much as two gallons.

However, I doubt that that one could get the sub tank to fill to that level. Our goal was 1.1 gallons at least. I'm going to venture a guess here that you cannot hold me to. My best guess at this point, if you were to top the sub tank off by gravity filling it from the main tank, since the main tank cap is higher than the sub frame, is that the sub tank will hold at least 1.4 gallons-THAT'S A BIG GUESS AT THIS POINT. As I have had zero experience with that how much the stock subframe will hold when it has been converted like a few people have done.

As soon as we have the tank done, I will fill both tanks from empty and post the total fuel capacity. So we'll have to wait and see!!

Another step forward today..............

As I mentioned in my last update post, the molder thought that they could supply the inserts for the sub frame tank, and in the end could not.

Well today I met with a top notch machinist, who's work can be found on a lot of off road bikes, and we reached an accord that will have him producing the inserts for our tank. I should have them in my hand in about two weeks or less. Which will be fine since the mold will not be ready by then anyway. So I feel like we had a good day at 70 Degree Racing by finding a machinist in basically one day that can produce the inserts for us!!

Dale

I'm glad you asked Code...........I was getting ready to make an update post.

I just got a call from the molder yesterday and he sent me some new pictures of the model which you can see at http://www.70degreeracing.com

The model is now in the female shop which is one step closer to the mold being made. We are hoping to have the tanks ready for shipping by the end of March. However, see my previous posts about the reason for the current delay.

The good news is that progress is being made, and the model is now at the female shop!!!! :bounce:

P.S. Even better news for us is that the total number of pre orders we currently have is right at 80 tanks, so we are really pushing hard to get the tanks into production!!!!