The Hodaka Club Forum

Hi there,

I'm coming from AdvRider, never ridden a Hodaka but I think they look sweet.

I hope I'm not offending anyone but I'm building a custom vintage MX bike and have been looking at getting an old Hodaka Ace 100 gas tank as I love the shape and polishing it up.

I was wondering if someone who had a spare tank could weigh it and measure how long it is and how wide the channel on the bottom to see if it would fit on my frame.

Is it a heavy tank, it looks to be about 2.2 gallons is that right?

Thanks a lot to anyone who can help me out

Hey Frey! I just shipped one so I can tell you...Weight is 7.2 lbs. Tunnel width is 3 inches and capacity is just a tad over 2 1/2 gallons. I hope this info helps.

7lbs! holy smokes! weighs as much as a gallon of water...

Thanks for the info!

edit: I just weighed my DR350 tanks by picking them up while I was standing on the scale. Empty the plastic dirt model and metal street model both weighed 7lbs... hm I guess that's the going rate!

Can someone please tell me how long it is? Thank you

The actual tank is 17" long. The center to center measurement from rear mounting holes to front mounting holes is 19 3/4".

edit: I just weighed my DR350 tanks by picking them up while I was standing on the scale. Empty the plastic dirt model and metal street model both weighed 7lbs... hm I guess that's the going rate!

Wait a minute, The steel tank and plastic tank weigh the same? Polypropylene has a specific gravity of 0.91. Steel a SG of 7.80. How can both tanks weigh the same if steel has a density 7 times higher. Is that empty?

If the plastic tank wall thickness were the same as the steel tank . . . you'd call it a balloon. (takes more plastic to have enough strength to hold shape AND gasoline)

Ed

Us riders from the Super Secret Hodaka Research and Meditation Center always fill our tires with helium for lighter overall weight. Rick Mott especially likes this modification. This is not recommended for Ed Chesnut, who like to keep the rubber side down.
Mike ( I wonder who invented the nut and bolt) Perrett

Archimedes is the one generally attributed with "inventing" the screw during the 3rd century BC.

So Ed, you are saying the plastic tank is almost 8 times thicker than a steel one? Could be. That would tend to explain it.

Thanks for the measurements Charlie.

The DR350 plastic tank is thicker and it does have a little more capacity there are little wings in front and on the dirt model they hold gas, on the street model they are just plastic and bolt onto the tank.

The plastic tank also has aluminum mounting tabs.

I'd say the plastic tank is probably more durable in every instance except sliding down a paved street at high speed.

This makes me think modern dirt bikes, which have a very small tank in the middle of two radiator shrouds might be slightly lighter weight plastic because there is no risk of the tank touching the ground past the shrouds.

I'd use a plastic tank but I feel like it makes the bike look more like a toy, for the build I'm going for, a sweet Hodaka might be the one!

Rick:

You've got the fuel tanks right there - take a look and you tell me about the difference in thickness between the steel and the plastic tanks. OR let's put Archimedes and you to work. Plunge a steel tank into a large container of water and let the water fill the tank (no air), precisely mark the level of the water in the large container. Remove the steel tank and drain all the water back into the container. Now plunge the plastic tank in and let it fill up with water (no air inside). Precisely mark the level of the water in the large container. Calculate the difference in volume between the upper and lower marks and you'll know how much more (volume) of plastic material was needed to make a practical tank.

Ed
PS: But did Archie invent the nut too?

California invented nuts. Fruits too.

Helium in the tires would at least give you something to do if you break down miles from home. You can practice your Mickey Mouse routine while waiting for rescue.

Hydrogen is what I used--even lighter yet, but then I read about that Hindenberg thing. OK I've hijacked everybodys thread--It's been a long day, I'm going to bed. Later--

Maxie

[quote="Bullfrog"]Rick:

You've got the fuel tanks right there - take a look and you tell me about the difference in thickness between the steel and the plastic tanks. OR let's put Archimedes and you to work. Plunge a steel tank into a large container of water and let the water fill the tank (no air), precisely mark the level of the water in the large container. Remove the steel tank and drain all the water back into the container. Now plunge the plastic tank in and let it fill up with water (no air inside). Precisely mark the level of the water in the large container. Calculate the difference in volume between the upper and lower marks and you'll know how much more (volume) of plastic material was needed to make a practical tank.

Ed

Ed, You almost have it right, but I think what I really need to is see how much water is displaced by weight. To do this the tanks must float. Plunging them in and letting them fill only will measure volume. There are easier ways than that to measure the difference.

Weigh them on a scale. Measuring the difference in weight of the displaced water only tells you what you already know by weighing them directly..

Am I the only one getting a little dizzy with the wandering of information being shared lately? Folks, you completely missed Ed's point and as I see it have insulted his intelligence. Go back and read his post... I am pretty sure that he realizes that if you want to know the difference in weight, that you might just weigh them...

I believe that the poor gentleman that posted the original question has his answer and can now make a decision based on weight versus fashion.
Dale

I was responding to Rick, not to Ed. But you are right that our OP has what he needs.

I too jumped in on the pirating of this thread, but the OP (Original Poster?) did get his answer right away -- so I think we can chalk up this particular "pirating" as pretty harmless.

The point of the description I gave before was to establish the difference in VOLUME of PLASTIC in a plastic tank as compared to the VOLUME of STEEL in a Hodaka tank (and had nothing to do with the VOLUME of FUEL the tanks held or their weight) . Of course it would have been good to mention that one could get that same information by looking up the density of polypropylene and the density of steel and doing a little math. But then that process wouldn't have any connection to Archimedes - and where's the fun in that?

Bye for now,
Ed