# Schwinn dx tank prewar/postwar fitment



## ADReese (Feb 26, 2022)

I'm looking to learn more about the dx tank fitment. Can anyone elaborate on the differences between prewar and postwar as they fit the frame? I'm not talking about tapped holes or horn diameter differences, just overall fitment. I'm considering running a prewar tank in my postwar('47) frame and I was curious how well it would fit.


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## 49autocycledeluxe (Feb 26, 2022)

I just recently got a pre-war DX tank. it does not fit my post war DX frame. it fit my prewar real nice.


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## ADReese (Feb 26, 2022)

That's great info! What were the fitment issues?


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## mrg (Feb 26, 2022)

Head tube angle changed, not sure about other frame geometry changes affecting the tank area but the front is a little different, and not sure when the change was, 46-7?


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## ADReese (Feb 26, 2022)

Thank you. My particular bike is a letter "I" serial. It doesn't have any of the '46 markers so I assumed '47. Guessing a postwar would be the best fit?


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## Just Jeff (Feb 26, 2022)

These pics should show the main difference on the shape of the front on the tanks. The drawn tank shape is a tracing of a 1939 Dx tank. The tank on top is a postwar repro tank. Head tube angle is different. You can reshape the tank but then you will have a gap at the front of the tank as shown in the second pic.
  This only apples to making a post war tank fit a prewar frame. I don’t think you go pre to post easily


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## ADReese (Feb 26, 2022)

Wow, that is a great example! Thank you very much for your time Jeff


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## ADReese (Mar 4, 2022)

Has anyone ever had luck putting a pre tank into a post frame? I see that it would be a tight fit. Seems like postwar black dx tanks are few and far between.


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## 49autocycledeluxe (Mar 4, 2022)

ADReese said:


> Has anyone ever had luck putting a pre tank into a post frame? I see that it would be a tight fit. Seems like postwar black dx tanks are few and far between.



when I put my prewar tank in my post war DX it was a loose fit. I don't have the screws so I was not able to mount it. I'd guess if you really wanted to do it you could make it work. you would need to put something between the tank and the frame to hold it tight.

if I think about it this weekend I'll take another look.

I figure prewar tanks are usually more than post war.


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## 49autocycledeluxe (Mar 8, 2022)

the red rusty DX is post war. the tank is prewar. notice the gaps. it fits loose in the frame and will fall out without being screwed to the other side. 















the prewar tank fits tight in the prewar frame. 










this would fit tight if I had another screw.


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## ADReese (Mar 8, 2022)

Fantastic pictures! Thank you so much for taking the time to do this. I've seen this question asked several times on here. Hopefully this thread will answer alot of questions for people. Helped me greatly!


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## mrg (Mar 8, 2022)

Ok, new question, did the tank change exactly pre-post, it seems like the 46 frames were still changing?


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## 49autocycledeluxe (Mar 9, 2022)

mrg said:


> Ok, new question, did the tank change exactly pre-post, it seems like the 46 frames were still changing?



I'd say 46 is the same as the others or the difference would be common knowledge.


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## mrg (Mar 25, 2022)

Still wondering when did the frame/tank geometry actually change and was the threaded vs clip mounting screw changed at the same time, here is my 41 Henderson, the tank that did not come with this bike originally fits this and my others prewar DX's ( a little problem because of the 2 spd clamps ) but has clips for the mounting screws, so did someone drill them out or things not change at the same time or on the pre/post war timeline?


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## GTs58 (Mar 25, 2022)

mrg said:


> Still wondering when did the frame/tank geometry actually change and was the threaded vs clip mounting screw changed at the same time, here is my 41 Henderson, the tank that did not come with this bike originally fits this and my others prewar DX's ( a little problem because of the 2 spd clamps ) but has clips for the mounting screws, so did someone drill them out or things not change at the same time or on the pre/post war timeline?View attachment 1595131
> View attachment 1595132
> View attachment 1595136
> 
> View attachment 1595137




The post war frames had the EF head tube with the top and down tube EF to the head so the angle and spacing of the tubes very well could have changed slightly. Are the head tubes the same length? Looking at the pre and post war pieces, I can see that the head tube leans back, more rake on the prewar frames.


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## 49autocycledeluxe (Mar 27, 2022)

I would say there are no tubes on the frames that would interchange if you had all the raw unassembled frame parts sitting on your workbench. 

the reason the mounting screw differences are even mentioned is you can't really tell one from the other unless you have an example of each tank in your hand and a frame nearby.

I thought they were the same and the only difference was the screws until I got one. I bought this one thinking I would put it on my postwar DX


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## mrg (Mar 27, 2022)

A fellow caber told me today he has original paint 41 DX's with tank screws/clips ( not threaded ) so seems like some changed some time in 41, that goes along with my prewar tank having og looking drilled holes with clips.


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