We use moped hubs on motored bikes, and we build some real hotrods.  They work very well.  They are same basic drum hub like Worksman uses up front, but they're wide (130mm) and they have bolt on sprockets.  You can lace one of thees hubs into a stock Simplex rim, not sure what the offsets look like though. Pat has pictures of them on his website, so check out his website:

http://sportsmanflyer.com/

It's hard to keep up with all the latest stuff on the website, but if you go to the Sportsmanflyer flikr page, you'll see all the latest hardware, including a complete folder with lots of pictures of the hubs we run.

This link will show you just the hubs:

http://www.flickr.com/photos/sportsmanflyer/6023605271/in/set-72157627379714327/

And this link will take you to the top of the flikr page (be sure to take your time to really look around, lots of cool goodies):

http://www.flickr.com/photos/sportsmanflyer


We always have lots of builds going, including some seriously fast bikes that we're working on now. As soon as we get thru those, we'll be building out a vintage Simplex with modern fourstroke power, either a GX200 or GC200.  The plan is to build one out then offer a bolt in kit for other Simplex users.  Pat builds some pretty high end stuff and Simplex setup will be of similar quality. It's always possible to build on a budget, but it takes more leg work to find the deals.

Rich

oh, and like I said before, Pat lists the worksman wheels (brand new) on his web site, he can make custom rear sprockets too.

Oh, and one more thing, I forgot to say you can get new worksman wheels from Pat at sportsmanflyer.com.  I might even have the components to build you a set.  I build the majority of the wheels for Pat and his customers.  If you run the predator motor, using a centrifugal clutch and a moped rear hub, or lightweight motorcycle hub is your best bet. The moped hubs are pretty good, have bolt on sprockets and if you run the Puch, or Lelue, you'll find they're near perfect match to the front worksman hubs, they even run the same brake shoes! The hardest part is getting the offset correct....

Nice job!

Thats a very nice original bike you have there, very cool. I think if that was in my garage, I would tear it down, individually clean every part, do a mechanical resto of the engine then bolt it all back together with the original paint.  It's only ever orig once, and at nearly 75 years old it is an amazing survivor.  The worst thing about it is the wheels, and I bet they'd clean up reasonably well.

One thing I noticed about my bike, the gas cap is on the left side, every other Simplex I have seen in pictures either has the cap on the right, or it has two caps.  Any idea why mine is different?

thanks, Rich

I figured it wouldn't be cheap, but the seat is a big part of the overall appearance of the bike, so I guess you have to dig deep to make it right.

thanks, Rich

Are the front and rear hubs the same, or are they unique?

Yep, guilty as charged, I am Pat's brother.

Pat keeps telling me the same thing -no tranny required with the Honda motor. Of course Pat is running a souped up GX200, whereas the GC160 does not have any hot rod parts avail at all and I think is around 4.5hp in stock form.

I have run Whizzers, little china motors and even a 9.4HP Morini motor, I find all of them lacking a broad power range that the tranny provides.  I only rode Pat's latest 200 model with GX motor up the street and back in the dark, so I don't have any seat of the pants experience. 

I appreciate you posting pics of this bike for perspective, the GC with it's flat mount pad is a very good choice for a Simplex conversion, the one in the pic looks like a stock setup.

Where do I find parts?  a nice set of rims, hardware to mount the tank, etc. And where is the serial number and how do I convert that info to a build date?

thanks, Rich

ps I will post some pic's soon of the bike.