Need some help with 70 degree frame pick

[Jack Skip]

I have been searching and researching but am not sure. I have some questions and need some help. Perhaps not using the right terms. Or just overthinking.

Is the standard 48cc or 66cc 2 stroke engine mounted at 70 degrees between down tube and seat tube? I have seen 70 and also 75 degrees. Mostly 70. Looking for clean and simple mount. As solid to the frame as possible. I cut out a 70 degree wedge and searched and searched without finding any current bikes to fit the 70 degrees. Did I say I searched.

Older frames are definitely recommended over current fair. Over and over. Don’t look to start another long debate on this. But where I live older bikes are not available. Do I need to re-think ebay and look online for older bikes? Or look for other current models.

Older frames have smaller down tubes, more in line with engine mounts. Are there any straight tube frames currently sold in 70 degree geometry with the smaller down tube?

Should I look for more flexible mounting options? Suggestions? Seen some billet mounts that may work. I want a clean look.

I have seen a few frames that have the 70 degree geometry. Mostly older. But are not available to me at the moment. Am sure there are more, but are any available new now?
Flying Pigeon
Hiawatha
Schwinn Motorbike
Schwinn Woodlands
Royal Enfield

I dont want to use a rag mount rear, but cant order anything until I pick a bike. Even thinking about wheel orders would be premature. But looking to lace a few good wheels for safety sake. I like Alex Rims and Weinmann products. Looking at double wall 12 gauge smooth rubber. Any suggestions here would also be most welcome.

Going to go with a 48cc 2 stroke. Not looking for a speed demon. Gonna also build one for my wife to ride along.

Please help.

Love this and this is what I would like to build. Wish I knew the frame. Would extend the seat a bit (I also do upholstery).


http://www.bikebound.com/2015/10/18/the-screaming-pigeon-by-dicer-bikes/





Really enjoying the info shared by all the members. Thank you, all of you.

 

[crassius]

using a bit of PVC in the mounts between motor & frame makes angle less critical

as always, I'd suggest not getting ahead of yourself with this and just building a cheap first build to learn what it takes to get one to hold together well

 

[Jack Skip]

Thank you for taking the time to respond. I am however very surprised by your recommendation.

I have already seen countless posts and threads about the lack quality welds on the cheap bikes, rag mounted sprockets shredding spokes and wheels, lack of adequate brakes, lack of quality wheels. Cheap tires blowing out. Should I go on? Your recommendation seems dangerous.

By the time I make a cheap build safe I would have more into it than buying quality first shot. IMHO.

And I am looking at selling these locally. Would hate a cheap first build become what people remember.

What do you ride?

 

[Jack Skip]

What is the mounting angle? 70 or 75 degrees?

 

[crassius]

until you have sufficient experience making a cheap build safe & reliable, you are a danger to anyone you sell to (or else hire a knowledgeable person to build for you)

 

[Jack Skip]

Never mind. Last night I designed an engine mount I can make in my workshop. It will accommodate any size tube and any angle. And will look super clean. And be super strong.