Rupp Roadster 1970(I believe) - Rear Wheel Assembly Questions

#1
Hi, I've been scanning through this forum for about a month, but this is my first post.

I've inherited what was originally believed to be a custom frame/bike that had been completely chromed, and given to my late-grandfather in 60's or 70's as a gift from a customer. Since our family business was a chrome-plating plant, the customer had every piece(that would take) on the bike plated before giving it to my grandfather. The engine hadn't run in at least 30 years, so I figured I would make it a little project of mine, which over the past month, has became a very large project that is now consuming my entire dining room table! I've kept all of the stock parts, but decided to go with a predator 212 motor, and a comet 30 torque converter. I'm also setting up the bike to bypass the jackshaft, and run the chain from the torque converter directly to the rear sprocket, which is seemingly very easy after adding a small chain tensioner lever.

Everything was going fine, until yesterday when I went to re-mount the rear wheel(with the sprocket reversed, now on the left side) and noticed that there are 2 brake drums installed on the rear wheel. I wasn't sure why there were 2 sets on the same wheel, so I removed the brake and hub from the side that does not have the sprocket, so that I could re-install it on the front wheel(which is where I would assume it originally came from). Once I actually got everything mounted, the wheel/axle just did not want to stay attached the the bike unless I torqued the axle enough to make it stay, and then the wheel was locked up from being to tight. I was thinking that maybe it was because the second brake drum was taken off, and considering that the cable guides on the drum lock directly in to the swingarm/frame, the wheel was now missing one of the supports to stay attached. But after looking at various photos and configurations on similar Rupp Roadsters on various sites, most that I've seen don't have a drum on the left side, so I know it can't be something to do with the drums. I will note, that while removing the rear wheel, it was noticeably difficult to get out of the swingarm, and had to have another person spread both arms out while I pulled on the wheel before it would budge.

Could anyone tell me what I'm doing wrong, and/or any tricks to mounting the wheel(with or without both drums on the wheel, preferably just the one so I don't have to re-attach the hub again(kind of a pain)? Sorry if this is long winded, or vague in any way, so please let me know if I'm missing anything. Thanks in advance!
 
#4
There should be a spacer ring between the wheel hub and brake assembly. Without this spacer the brake assembly will press against the brake drum and prevent it from turning freely.
Thanks for the help!
Would you happen to know what size the spacers are meant to be? I doubt I’ll find original parts, but I imagine I can find an equivalent if I know the specs.
Thanks again!
 
#5
Sorry that I don't remember the thickness but it needs to be long enough to prevent the parts from rubbing when the axle is tightened up to hold the chain adjustment.
 
#8
That's a beautiful bike.

Where'd the original engine go ?

In my opinion, it would look so much better with the original engine...please tell us you are getting it going, and will be replacing that predator with it.

Have fun with it !

Also...Welcome to the OldMiniBikes...!
 
#10
That's a beautiful bike.

Where'd the original engine go ?

In my opinion, it would look so much better with the original engine...please tell us you are getting it going, and will be replacing that predator with it.

Have fun with it !

Also...Welcome to the OldMiniBikes...!
I apologize, I should’ve clarified; it was the original engine that wouldn’t start. And since I am completely new to the mini cycle and small engine world(much more knowledgeable with cars), I figured I could rebuild all of the original powertrain(motor, torque converter, jackshaft assembly, etc.) on my dining room table, while having a more powerful and more modern little toy to have some fun with. But any background/information on this particular model(like I said, I’m assuming what my bike is from photos online and nothing else) that anyone could pass along would be greatly appreciated!
 
#11
That's music to my ears DLendon !

And you are in the right place.

I didn't know squat about small engines except how to change the oil, when I joined up. I started asking questions, and have continued to do so...and have received some really great advice, and learned a ton.

There are folks on here of all different skill levels, and everybody seems to love to share, to help others learn.

Have fun with your new bike, and just ask away once you start working with that engine.

I'd start out initially, changing the spark plug, clean out any old gas in the tank. Put in just a bit of fresh gas...and see if she fires over. If she fires, but won't start on gas...try spraying some starting fluid in to the carb...and try to start again. If it runs on starting fluid, but not on gas...clean the carburetor, or just replace it for now (keep the original carb, and rebuild it at your leisure).

If that doesn't get it going, then start asking questions in the section that relates to your engine...I imagine it's a tecumseh of some sort ? Folks here are glad to help.

Enjoy the process, and keep us posted of your progress !

Have a good one.
 

GustoGuy

Well-Known Member
#13
That's a beautiful bike.

Where'd the original engine go ?

In my opinion, it would look so much better with the original engine...please tell us you are getting it going, and will be replacing that predator with it.

Have fun with it !

Also...Welcome to the OldMiniBikes...!
It is a Resto-mod The biggest problem with putting a "p" engine on a Rupp is routing the exhaust. I have one in my Rupp Roadster 2 too. I bought a Robertson torque tube muffler which fits perfectly within the frame and looks nice too. He should make a ceramic coated chrome one. That would look great and prevent heat transfer. The "p" engine has tons of power and is a better choice for adult-size riders. A stock HS40 is great for smaller riders or younger teenagers.
 
#14
So a little more than 3 months later, the bike is about 95% of the way there. Just figuring out some odds-and-ends, as well as refining some minor things. I tend to be OCD when building anything, and considering it's my first experience with a motor on 2 wheels, it took me much longer than I initially anticipated.

I began the build with the idea that I would bypass the jackshaft, and just run the chain directly off of the comet 30 TAV mounting plate. There were way too many issues with fitting the mounting plate within the frame, along with chain/sprocket misalignment(I'm a car guy, so chain drives were a foreign language) and I ended up having to revert back to the original jackshaft design, and using the comet 30 in place of the Rupp torque converter that came on the bike. The jackshaft was a learning experience to say the least, as I had to replace the completely rusted bearings, fitting a different length jackshaft to work with the torque converter, while keeping the sprocket (powering the rear wheel) in the same place.

The brakes were also quite a learning experience, as I've never dealt with drums, I had no idea what I was looking at until completely disassembling them and rebuilding them again. They were much simpler than I initially assumed after I essentially reverse-engineered them, cleaned them out completely and installed new springs. At the moment, the main thing I'm struggling with is getting the return spring(on the outside of the drum) properly attached. I couldn't figure out how to get the spring engaged and locked into the hole while clipped on to the brake arm. In the meantime, I installed a couple springs between the arm and the cable retainer, to give me at least some semblance of brakes.

As someone mentioned above, the exhaust was also a challenge, but ended up having the header bent by a local exhaust shop so that it fits within the frame and exits out the rear left side of the bike(will post a couple photos so you can see what I'm talking about). I did reach out to Robertson Torque Tubes, but I think they may have forgotten about me after a couple emails back and forth, so I moved on to more important things on the bike.

Since I am at work, and have spent a huge portion of my free time over the past 3-4 months on this, I don't have enough time to elaborate on everything, nor can I recall all of my "trials and tribulations" of my first experience with a bike. It has been extremely satisfying, frustrating, maddening, and most of all, a lot of fun seeing it come together. If I were to do it again, I am sure it would be even more enjoyable and much easier, since this was a huge learning experience and an insight in to minibike/motorcycle engineering. I can say that I'm glad my dad is a long-time motorcycle enthusiast(he grew up riding them in England), as he gave me quite a lot of insight in to how certain parts of the bike I didn't quite understand from visual inspection.

I will post more here when I have some additional time(and I'm not stuck working on the bike), but thank you to everyone for the kind words of encouragement, as well as the help/information provided. It is appreciated! (I apologize if anything above is redundant, I can get ahead of myself when I'm excited about something!)
 
#16
Please excuse the sub-par photography, as well as the cosmetic condition of the bike(I didn't have the chance to clean it, and it was missing some cosmetic pieces as well)
 
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