Greetings from Wisconsin

[McBob]

Hi Everyone
I have been looking around on the forum for couple months now and thought
I would introduce myself to you all.

I had my first motorized bicycle 45 years ago when my cousin and I each built our own with the help of Marvin the local gearhead dragracer that lived down the block that I grew up on. Mine was a two stroke tecumseh and my cousin had a 5 horse brigs build (the first motors we found). Marvin helped us weld the motormounts on the frame and the sproket to the rear hub. He helped us line up the motor to the sproket and cut us loose and said have fun. We did have a lot of fun on them riding around the city and the countryside until the cops said we couldnt ride them any more.

Any way, now Ive got the bug again and I've decided to motorize a 51 cantilevered frame schwinn (with a Pullman headbadge). I found the bike in a basement of an abandoned house I was rehabbing and the owners of the house said I could have it. It just looked too cool to let go. I will start a build thread soon with the details of that. It's really cool How you guys all share your knowledge and help one another work stuff out. I am looking forward to getting to know you all better. I know the general direction that I want my build to go, but I got a lot of questions. Like 2 stroke or 4 stroke, Jackshaft or no jack shaft....

McBob

 

[Dan]

Howdy McBob, welcome.

Great story! Marvin sounds like an incredible guy.

Looking forward to seeing your build.

 

[Mannhouse51]

Welcome to the forum ! Can't wait to see what ya build.

 

[McBob]

I guess the first thing to learn is how to post pictures. Figured out how to resize them for web use. It worked! Next is the build.


Heres what I'm starting with:

 

[F_Rod81]

First things first, Welcome to the forum. You will find everything that you need here pertaining to Motorbikes. That bike will look very nice restored and with an in-frame motor. I'm gonna keep an eye on this thread to see your progression.

 

[MEASURE TWICE]

Welcome McBob

Will your bike be a kit or a DIY'er type?

I am geared toward doing all DIY stuff and like to see what people come up with. Of course there are also kit bikes that have a bit of mods that I say catch my eye also.

I had built my prior motor bike back in the same 70's era as you did with the help of my dad which modded my drill and bolt through frame approach. Sort of weakens the tube. It was better when he made a brazed platform to be able to move engine fwd and aft so to adjust a direct drive v-belt to washing machine pulley on rear wheel. It was a wood sandwich connect to spokes on I think 24inch wheel frame.

Now I want a versatile design with many gear ratios. Can't ride the streets (no pedals on it and over 2hp), but eventually to get OHV sticker for CA state and Fed BLM motor cycle parks and the private ones too.

I have a jackshaft that I am just now going to adapt a bit to allow a second 10inch like washing machine pulley that goes to a belt clutch I expect to get if I think it can work. It will give about 25 to 1 where as now I have 8.3 to one ratio. With one of the jackshaft smaller pulley changed I'll vary from parade speed to hill climb to well maybe Lands Speed on salt flats if I can think how to get in contact and have time to get with that done.

The situation is that the 10 inch pulley will be right close to the 2.3 inch belt clutch and the amount of belt that rides on the smaller pulley due to the angle it has when it reaches the belt clutch pulley has me cause for concern that there might not be enough friction.

I have a belt clutch I'd like to mod to be able to use, but it must be 1/4 not 5/8 as the shaft it is sort of stuck on is a Briggs 5S which I just rather keep for something not needing to have much power.

I was thinking it would probably not be very easy as going from a smaller shaft to larger, you just shim.

Anyway the 70's Era Aluminum Briggs has 3hp I revamped and is about the same weight as the cast iron 5S but 1/2 again as much hp, so that is what I'm using.

I'm not sure but I think the 5S would be about 2hp. Both engines had the valves and seats cut to restore the angles, so they have their compression like new.

The 5S was a trash engine with stuck valve I fixed, the newer one was $5 at SJ Flea Mkt from my time tinkering 30 years ago but now have it on a trash pulled 60's Era JC Penny Foremost 26inch frame that is nearing completion.

http://motorbicycling.com/showthread.php?t=29678

http://motorbicycling.com/showthread.php?t=29678&page=2

You may see my post on the two above pages

MT

 

[chainmaker]

Hey Bob welcome to the forum. Glad you posted, that bike is going to be nice you cant beat the oldies!

 

[McBob]

Hi everyone
Thanks for all your welcomes.

I looked at the site and came up with a plan. I started assembling parts for the build. Im not sure if it is the right place but i posted it on BTR and vintage bicycles.

Measure twice, I think for this build I will use parts that I buy from vendors. Im thinking a Honda motor,4G T transmission, jackshaft kit, 5 speed hub and drum brake front.
McBob