Firemarshal71's Open Class Chopper

#1
Well here goes, I wasn't sure if I even wanted to start this but over the past couple weeks had a lot to think about and realized I was going to do another build anyways so why not...

I bought this "cough" 71 Rupp thinking I was going to do a vintage restoration but after consulting with a few members on here, found that the bike I purchased for $250 was garbage and after spending a couple days adding up all the costs associated with finding the necessary parts, realized it would end up being probably twice what the bike was worth. My new plan calls for modifying the current frame, extending the forks and adding a 'fat" tire out back driven by a torque converter, I hope will end up resembling a chopper of my own design and liking. the engine will probably be another 212 predator because the 3hp briggs that i just pulled off it has something rattling around in the cylinder and the clutch is seized. Either way it will prob cost more than i want to spend (or admit) but I'll have fun doing it. I'm going to go puke now thinking about chopping up a '71 frame.
 
#5
no need to puke.
your right that it would cost more than it would be worth restored.
do with it what you want :grind: :hack: :weld:
i'll be watchin
 
#7
I never used to, but as time rolls.... so does my change in taste. I stared at this rupp frame for what seemed like an hour and I could see (or imagine) the resemblence of a chopper when it was slanted back with engine plate horizontal (in the entry photo).

ahhhh, the dirty mitten... I was a troll until age 20 (S/E MI in Monroe County) then the Navy got a hold of me and took me around the world for the next 20yrs.
 
#9
I grew up in Chicago and my Dad had a friend with a cottage on the shore of Lake Michigan. We used to go there every summer.

Then I joined the Navy for 22 years of travel.

As soon as I saw you pic listed as a chopper, I could see it with the motor plate horizontal. Or close to it. I like it! :thumbsup:

The more the merrier!
 
#10
The vision on paper

This is my vision for this design. I was kicked out of art school in the early 90's so my proportions may be slightly skewed, but I think this is doable. the only area Im not sure about is the jackshaft setup. I wanted to use a TAV but may have to stick with a basic clutch with jackshaft because of the wide tire. I think the back will be a golf cart DOT tire 16*6.5*8 (nothing too extreme). I also think I can take the springs out of the Rupp shocks and make a springer front end on the extended forks since the current fork is also seized up and those springs are junk.
 
#12
A few more mockups on the bench

Set up a few more mockups on a bench I threw together last minute from some extras left over on my last job site. Wanted to make sure before I started cutting the frame that everything looked like I wanted. Had to pull out the old propane heater, feet and hands were starting to numb from the cold. I also took one of the mockup photos and played around with it in MsPaint.

The overall length is going to be just over 5 ft. the back wheel still needs to be tucked in a couple inches but that's as close as i can get it until I cut out and modify the Rupp seatpan. I may have to move the jackshaft assy back a few inches too.
 
#14
That's just cool!:thumbsup:
Thanks Buck.

I haven't done too much lately- been taking on additional jobs at my work to help pay for some of the expenses that I incurred over the holidays. Since I left off on the 4th I've had a few days to stare at this mockup, clean up the garage and get the shop setup for this build, and order some materials. I tend to change my mind quite a bit so I never start a job unless I know at least 90% what I want to do and if I am capable of doing it. I had a design issue I needed to find a solution for because the way the frame was, would cause the chain to contact a frame member and I believe I solved it now by planning to raise the jackshaft up and aft.

So...... I rocked the frame back a little more and stretched the mockup frame to a full 6 ft. I think I like this appearance better than the smaller version. I am also trying to keep the bike as true to Rupp styling as I can (small details like the jackshaft inside a tube, the seat pan, and etc.) In order to keep the shape I want, I am going to attempt to weld my frame around the old frame and then remove the old after Im done. Will begin with the footpegs tomorrow eve which will connect the lower frame rail with additional bracing as needed. The attached picture is going to be the FINAL design I have chosen.
 
#20
QUOTE=Stangrcr1;631378]Looks good!

I am doing the same with building the new frame around the old, then cut the old out.[/QUOTE]

:thumbsup:

it just seems to make sense to me, but I havent done anything like this before either.
 
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