Kirsch Special - Swing Bike Project (no welds so far)

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SwissGuy

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I don't know how, but somehow I got drawn into a SwingBike wormhole last night, that reached it's culminating point through various tube videos at this thread here: https://ratrodbikes.com/threads/swing-bike-gallery.31549/
It itched me that hard to build one of these that I went scoring the local classifieds (ebay-kleinanzeigen) to hunt for suitable project bikes for an affordable price. I ended up spending 35 € (15 for the purple and 20 for the red) in total on these two bikes today:

IMG_20230326_193050044_copy.jpg


When I picked up the red one it had a nice extra on the rear rack, that totally made it worth the money spent on it:

IMG_20230326_193059117_copy.jpg

No Brooks, but It will look nice on another project sometime...

This will be a quick one (hopefully) as I have only four days time until the wife and the kids come back on Friday and the living room has to look like this had never happened... :giggle:
I'll try to achieve my goal without welding but there is also a plan B...

First order of business will be to strip them down to the bare frame...
 
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SwissGuy

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Frames are stripped down as far as I got with the tools on hand.

IMG_20230326_212451688.jpg


I've got a vague idea how to continue, but will probably need to order some stuff...
On the way I discovered that the purple bike got folder pedals. They will go on stock and the classic Union will be used for the project.

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Tomorrow I'll have to go through the parts I have around here and then we will see how I can continue...
 

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And chopping time:
Sawed both frames apart with the jigsaw.
IMG_20230327_175558495.jpg


As I already realized with my take apart bike, the outer diameter of the top tube almost exactly fits the inner diameter of the lower tube. So I only needed to cut them to size and sand off the paint and both end slide into each other. As there is also some tension they needed a bit of convincing with the runner mallet..

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The big picture is already visible:

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Now I just need to bolt the red fork to the purple seattube..

IMG_20230327_185118070.jpg


I even might give it a test ride by tomorrow...
 
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Made good progress, everything is bolted together now and feels reasonably solid...

IMG_20230327_204708496.jpg

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Time to make a bike out of this contraption again. Just need to get the workstand up here from the basement...
 
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Love the project! Looks really neat!

There is only one thing that scares me; the attachment of a fork leg to the frame, I'm scared it will bend at the fork tree or base. Is there any possibility that you attach the part on the top of the fork near your seat tube for added stiffness?

But again, respect for just doing it like this, absolutely awesome!
 

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Love the project! Looks really neat!

There is only one thing that scares me; the attachment of a fork leg to the frame, I'm scared it will bend at the fork tree or base. Is there any possibility that you attach the part on the top of the fork near your seat tube for added stiffness?

But again, respect for just doing it like this, absolutely awesome!
Believe me, I'm fully aware of that problem. I have something in mind, but that would need some extended fab work on a second stem.
I think as long as I don't overstress this (aka jumping and off-road use) it should be fine. But I saw several swingbikes with a similar setup. Some of them bent, some not... 🤷
My main goal was to still be able to take it apart and service the additional headset.
 

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Some pictures taken after todays testride.

IMG_20230328_172007495.jpg

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And it even folds into the elevator:
IMG_20230328_172517541.jpg


I'll post a video as soon as I'm done editing and uploading. At first it feels very strange and wobbly, but as soon as you get the hang of steering with your but, it's pure fun.
So my to do list looks like this for tonight:
  1. Eat something! (I'm starving, but hey bikes have priority!)
  2. Go to the meeting of our gardening community (I have to and I hope it doesn't take too long)
  3. Grab the kids Hope4muscle bike, exchange the brake calipers and levers with the ones comeing from the red donour.
  4. Mount long reach front break calipers and whatever breaklever I can find in the stash (this thing is almost uncontrollable only with the kickback)
  5. Mount a different saddle with more "grip" for the rearsteer
Later in the game I'll try a smaller front (26 or even 24) and a handlebar with a higher rise (I have both in my campground stash, so I'll head there tomorrow after work...
With a smaller front I'll try to reduce the angle of both headsets to make it more rectangular to the ground, thus making the swing hopefully need less force...
 

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The video is a bit boring, but it shows how I go from wobbly and completely unstable to actually "swinging" (ok, it took me more than 4 minutes and I cut out a lot...)
 

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Very cool. Seems like a joy to ride!
Now you can change your name to "Swingguy" :thumbsup:
Yeah, it's really fun to ride and to play with speed, gravity and centrifugal power. But it's a full body workout to operate this thing. I tried for about 30 minutes yesterday and especially my core muscles feel a bit sore today... :grin:
 
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I like it when people find ways to create complex things without welding. This is a huge success. Cheers to you.
 

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I like it when people find ways to create complex things without welding. This is a huge success. Cheers to you.
Thanks! 🙏
I even found a solution to relief some stress from the second pivot.I will fit a little block of wood in between the two stems tomorrow. Today it's was to late to take out the drill (I try to be a friendly neighbor)... 😉
IMG_20230329_213213762.jpg

It's a chopped seatstem and some other hardware...
And I also drilled a hole through said head tube to be able to block the pivoting, as I realized that the bike is easier to handle like this when you have to schlepp it up the stairs and as I sometimes ride the Berlin S-Bahn and take the bike with me it's easier as well.
Awesome build. Cheap, cool, fun. Brilliant.
Thank you! 🙏
So far this build cost me 35€ for the bikes and 10€ for hardware. All the rest comes from my stash. If I count in today's drive to the campground and back to get some more parts you could guestimate that this build cost me 50.- € in total.
 

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This is how the bike looks now after my little trip to the campground to get fenders, a mini ape and a nicer brake grip...

IMG_20230329_231437855.jpg


If the weather allows I'll take some nicer daylight pics tomorrow...
 

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This morning I took care of the stress relief. If you ask, why the eyelet bolt, it was simply the only bolt with enough length and a 6mm diameter I had on hand...

IMG_20230330_075234408_copy.jpg


With this taken care of I rode the bike to work. First with the safety pin in, because on most of the roads I use to get to work, you seriously don't want to swing along with cars making close passes at 50 km/h or faster...
But on the last few meters I took the pin out (while still driving, you can see it in the beginning of the video) and man it was short, but loads of fun! The mini ape makes a huge difference in handling the swing and the front brake is also a very welcome addition.
 
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the original swing bikes had a return spring (if that's what it's called). Are you going to put one on this?
 

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