Rätte-Hengel...

Hello all,
I’m a newbe here, but i have been lurking awhile and have always especially really enjoyed the Build-offs!

I’ve built a couple of motored-bikes in the past, but never before a true Rat Rodder. Perhaps some of you will recognize me from a another Motorized Bicycling Forum where i do occasionally post and have shared my pervious projects? I know some here are common members.

Anyhoo, a friend recently ask me if i would build a Ratty motored bike for him and it just so happens to fall within the time constraints of BO12. From now on i’ll just refer to him as Chris. Chris initially sent this picture of stuff he mocked up himself on his garage floor-



His mandate for me was build something Ratty, or perhaps even post-apocalyptic. He would supply all the parts new & old. He doesn’t even want to see any progress photos until all done and running, he’s a very creative guy so it surprised and flattered me that he didn’t want any input.

I like to name all of my projects and because of his Dutch heritage i’m calling this one “Rätte-Hengel” which is probably actually a bad Google translation of “Rat Rod”. But hey it has a nice poetic flow in English. LOL!

Chris is a flea market king and always seems to have a lot of interesting vintage stuff on hand, along with the frame in his concept photo he sent this big pile of stuff to work with. We agreed to also use that big old white Tecumseh 5HP engine shown here instead of the little 2 stroke snow thrower engine that was in his original photo.



But sadly i didn’t realize the pto shaft had been cut short and wouldn’t work with the Torue-O-Verter CVT I was planning on using until i started taking tins off. So I ended up buying an inexpensive CX200 Honda clone from Harbor Freight and tipped it upright for effect. Perhaps it’s just as well since there will be less risk from an vintage engine of unknown internal condition.

Because he is a creative person i suggested that he could be responsible for distressing a new engine to match the rustiness of the rest of the bike, and i thought it might be a good idea to somehow give him some sort of input. But when my wife was throwing away a old coffee maker i couldn’t resist using this stainless steel tray, it fits the shroud just like it was made for it! Coffee stains to remain while under my care, Ha!



I decided to use the same frame that was in his concept photo, but to stretch the rear triangle out about 7 inches. I feel adding length to a old bicycle makes it feel a little more “man-sized” and comfortable to ride, and I think it just looks better too. I don’t have a proper aluminum frame building jig so I just cobbled up my own with some old wood...

Before the cuts-





It’s always a little scary to cut a vintage frame so I only hope that I’ll do it justice in the end...



Because this build will only have a single brake I wanted it to be substantial. I’m going with a vintage Honda CB350 rear hub (I think that’s what it is?) and had to widen the rear stays nearly 5 inches to accommodate. I put solid rod inside the cut stays to beef them up, make it easier to get kink free bends, and it also helps to have a little extra meat while welding...



Also because this will have a powerful and heavy engine I’ve added several and very stout gussets throughout. The rounded one above the bottom bracket is 3/8" thick and will carry a jackshaft. And all new and any old tubing near the engine is reenforced with generous lengths black pipe sheaves internally...







Welded!





Here’s my solution for keeping this a actual pedaling bicycle- I cut the treaded end off a BMX style freewheel hub and welded it to a plate so it can be simply be bolted right onto the Honda hub. Of course an extra wide crank will have to be fabricated. I also decided to repaint the donor wheels. I don’t mind mixing a few odd colors in, but they were a truly awful shade of yellow (seen in the background of some of the frame pics). Plus i think the red really pops!





To get some real leverage for a motorcycle sized drum brake I’ve modified some old worn out Visegrips for the handle. And By dipping the vintage original white grip in boiling water for several seconds I was able to force it over the slightly larger throttle body without splitting it...





The original fork was bent in about 5 directions and I wanted to build a custom leaf springer anyway. And for it to be very heavy duty!
A nice robust vintage fork and some leafs trimmed down from a 1970’s Snowmobile is a good start for the challenge of strength...



5/16” plate and rear stays from a vintage Schwinn 10 speed for the bracing and some 1/4” taps to add mass & wear surface to the dropouts...







Welded & bronze brazed!



For the rockers I stepped up to thick 3/8” plate to give them lots of wear surface, it took a couple of cutoff discs just to hack them out!





A little distressed paint to finish these parts off (btw, the camera flash makes that rust look much brighter that it actually is). Since with a leaf spring I only need 2/3 of a fender I decided to turn it around and use front end’s white triangle graphic & pin striping to match the back of the rear fender...







I probably spent 4 or 5 hours taking that fork off the bike, into a vise and back to tweak and bend the legs tiny amounts to get it to run true, level, and plumb, (worse than building a wheel with a old warped rim!) but I have it now and can finally begin to fab the front spring legs!

Well, this is a very long first post but it covers all my progress retroactively as I sit here and write. From now on I’ll post more regularly as work is finished!

And looking forward to finally meeting some of you!

Thanks,
-Mr. B.
 
Apr 28, 2017
18
19
46
Netherlands
Very nice to see the progress on this one, love to see the end result of the bike. The name sounds cool as well although the first part of the name is actually more German then Dutch as we don't use the " on the letter 'a'. But I would stick with it as it sounds way better then "rathengel" in dutch


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Thanks for the nice feedback everybody!

I was really hoping to have some more progress to share by now, but got side tracked by some family stuff this week...

Soon though, planning to work on it all day Sunday!

And yes 1974sharks, i figured a real translation would be more complicated than just simple me stringing some words together with Google translate. Please forgive my linguistic ignorance as i do just stay with the name as is. I just like umlauts! LOL!

scrumblero- I did add a couple of inches of height to the seat tube and bent the down tube downward just below the cruve that follows the front wheel to make it the engine fit. Even with that it’s pretty tight, only about a inch of clearance above the engine and i bet i’ll have to get one of those right angle spark plug boots after the tank is done...

Thanks again for a warm welcome!

-Mr. B.
 
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Apr 14, 2015
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Holly molly modifications x 2 ...
You have got some wicked engineering and fabrication going on . This bike is going to rip


Sent from my iPhone using Tapatalk
 
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Wow, that Photobucket thing is an sudden & inconvenient disappointment!
But i do have some further fork fabrications to share-

I discovered that if i really bent the old snowmobile springs they somewhat stayed bent...

Not really a desirable trait for a spring in a springer suspension fork.

To help with that i decided add an additional full length leaf from a car (something my auto mechanic gave me and possibly from a Mercedes?) Shown first with some blue tape to guide cutting off a little excess and then with all reinstalled

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It stiffens everything up more that i like but i feel way better about it wanting to eventually sag.

For the front legs i found these forged lag screw fence gate hinge pins at a home improvement center to use them for eye bolts. I cut the lag screw end off, cut and pounded the pins out, drilled those to size and then die cut 7/16” 20 threads to the shank.

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I used 1/2” tube for the in-betweens and tapped the ends. I also put solid rod inside to help make kink free bends and add some extra strength (measure three times, cut once).

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Here everything fit together and awaiting brazing the eyes. I also still need to drill cotter pin holes in the axles (all grade 8 bolts) and trim off their excess...

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That's all for now but hope to work on it again later today!
 

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