Frame Selection


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1:21 AM
Apr 29, 2008
Hello Whizzer fans, I'm collecting parts to assemble a Whizzer bike around a NE 5 engine kit that I purchased a while back. So far I gotten a set of wheels from Worksman , a springer fork and some smaller items. I would like to ask for your input as to frame selection .I currently have Two Schwinn frames to choose from ,one dated from 1958 and one as yet undated but much later. Both frames are of the cantilever type. Both are bicycle frames and don't have the drive belt offset in the frame that I've seen on some of the Schwinn frames built spacifically for Whizzer. My questions are, can these frames be bent to provide drive belt and sheave clearance without damage to their intregity or making them unsafe , and does anyone know if the Schwinn Whizzer frames of this cantilever type were specially reinforced for strength and the bicycle frames were not ? I'm mainly concerned for structural
safety. Sorry to be so long-winded.Thanks Steve

Schwinn Made the WZ bike for a motor kit but as far as I know the frame is the same as any other except for the crimps. I crimped my own frame and it worked great. Her is how I did it.( AND YOU THOUGHT YOUR QUESTION WAS LONG WINDED)
First find a chunk of steel 3/8 in thick x 5/8 in wide x 2 1/4 in long
grind one long edge so it comes to a peak (like the roof of an extra long monopoly hotel) round down about 1/4 in of both ends of the peek so that they are not sharp.
Next find a 7 in + length of 1 1/4 in x 1 1/4 in x 1/8 in. wall alum. box tube. Cross cut one length to 2 1/2 in and one to 4in. Cut each length wise to make each a peice of channel. For example the 2 1/2 in part woud end up at 2 1/2 x 1 1/4 x 1/2 and so on with the other part.
Purchase some JB weld epoxy and a bit of dubble sided masking tape (sticky on both sides basicly carpet tape.
Mark your frame with a sharpy where the crimps need to be.
I found that on my schwinn
B-6 frame that the upper crimp measured from the seat tube back needs to be centered up and down and back 5 1/2 in to 8 3/4 in.
The lower crimp from the seat tube back needs to be centered up and down and back 8 1/2 in to 11 in.
Your motor position might be different so mock up as much as you can and make sure you know where you need the crimps to be.
The next step is to carfully wrap a bit of wax paper around the frame at the two crimo spots and tape it to its self on the inside so that the outer side of the wax paper is smooth and will keep the epoxy from sticking to the frame.
fill the 2 1/2 in alum- channel with a healty amount of JB weld epoxy and press it over the out side of the frame tube verticly oppsite where the crimp will be.Have some paper towels ready to wipe off the squeez out. Tape the tube in place so it can cure. Do the same for the top tube with the 4 in bit of channel. When these three tools are made you will be able to crimp as many frames as you want, so long as it is the same frame type.
The Crimping process is easy.... with the dubble sided tape stick the steel tool horizontaly to the jaw of a medium size or larger Bench vice, then hold the alum-epoxy support you made to the frame in the right place have a freind to help hold the bike its a bit difficult alone (I did it alone) line up the center of the frame with the center of the steel tool and tighten the vice hard to do at first, one it starts to crimp it gets easer. Tighten until you feel resistance and you will have it crimped as far as it can go back off the vice and it will look great because the alum-epoxy tool keeps the shape of the outside of the tubefrom distorting.
Hope this helps. Its worked well for me.

Brent Merkley
Hi Steve,
The Schwinn frames can be "crimped" in two areas to clear the belt. The Original WZ, later called the S4 was heavier made, and had a stronger spring on the springer front end. The WZ/S4 also had larger spokes [my original 1948 has .120 spokes], the fender was cut to clear the belt, and the S4 had a special arm for the brake with a bracket welded on the frame. If I were you, I would use the older frame, mainly because they are just better, period! I have installed the Whizzer motor on a 1950 Schwinn Panther [DX style frame], and simply used extra washers on the rear axel to spread the frame enough to clear the belt, but is close. I wouldn't worry about frame structure if using an older frame, because on a bad day the older frames are better than most made today on their best day. If you need pictures, send message requesting them to I am going to a Whizzer show but, will return home on Monday May 26th.

Have fun,

Have fun
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Quenton is correct the old frames are simply great frames. One thing you should be careful of is this, these frames that were made in the 40's and 50's have been around so long that no one knows what they have experenced. If the original paint is still in ok shape or you can see the original paint under a newer paint job your probably safe but if the frame has alot of rust the fear is that its been out in the weather so one needs to concider what would happen to a frame leaning up aginst a house full of rain water for two or three years. Chose a frame that looks like its been well cared for inside and out for a motorbike frame. I have cut two frames up with a hack saw one of them was pretty scarry on the inside. The old schwinn frames were mostly " Electroforge" welded and are bomb proof!

Hi Brent and Quenton ,
Thanks for the helpful suggestions ,I will make the tooling to do the crimp, that won't be a problem (great discreption Brent).I just wasn't certain that the crimps should be done to a standard bicycle frame. I've had the older frame since it was new so at least I know it's history(never left out in weather). Thank you both for the help.
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