Flyer Production

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fasteddy

Well-Known Member
Feb 13, 2009
7,475
4,962
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British Columbia Canada
I still think that if you want a drop loop frame the fastest and cheapest way is to buy one from Sportsman Flyer. They proved the quality of them by going over 80 mph on them and setting speed records.

I was reading a thread on Rat Rod Bikes forum about a builder who after trying to get the drop loop right and couldn't so he went to a place to have one made up. They charged him $300. All I could think of was that is he had gone to Pat and bought one he would have many dollars and fewer problems ahead and most likely a better product.

Steve.
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
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california
They proved the quality of them by going over 80 mph on them and setting speed records.
Steve.
Thanks Steve. We just ran two bikes over the weekend at El Mirage. We now run both the salt flats and dirt dry lakes. Both bikes were up 3-4 mph only to slow down right before the timed area. Either ignition or carb. Most likely carbs. Anyway, bikes felt very stable and powerful.

Here is Rich at 80.747 mph on his 175cc bike.

El Mirage May 2016 by Pat Dolan, on Flickr

Me at 82.074 mph. This is right at the line where speed is measured. Man, I learned a lot looking at this photo. I would tuck lower but need to see where I'm going!

El Mirage May 2016 by Pat Dolan, on Flickr

Rich and I right before tech inspection. '49 Ford chase truck and Rich's cycle truck was used as, well, a cycle truck. We drove the old F1 all the way down from Gilroy and back. Doing our best to keep history alive!

El Mirage May 2016 by Pat Dolan, on Flickr
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
83
california
Thought I would share a quick update on what I call my "pedal bike" Flyer frame. This frame has been a joint effort with myself and Worksman where they supply the Worksman INB rear triangle and I build forward into the Flyer frame with a drop loop for added engine space. These frames have 110mm hub spacing for the Shimano coaster brake and other 110mm spaced rear hubs. This hub has been fine for smaller engine builds but bigger engines require bigger hubs and these are all 130mm or 135mm standard. The electric bike guys also need this wider spacing. Bigger engine builds also need larger 1/2" dropout slots. I took a few of the INB frame stay and chain stay tubes, added an additional bend to take them from 110mm to 135mm and then laser cut beefier dropouts to finalize the 110mm to 135mm conversion, then brazed them up.

Standard INB bottom bracket, seat post and 110mm chain stay tubes. Notice how straight the tubes are after the initial bends at the bottom bracket. You can also see the nice forming for the dropout to slip into where it then gets that good old school brazing.

135mm Flyer Pedal Bike by Pat Dolan, on Flickr

The upper dropout in this picture is the standard Industrial News Boy dropout and below it is the 135mm version. The small square hole in front of the slot will get a small tab for proper chain tensioners. Nice extra thick stamped washer completes the dropout package and helps spread the load of the larger axle nut.

135mm Pedal Bike by Pat Dolan, on Flickr
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
83
california
This is a picture of a test fit of the 135mm spaced components. You can see the added bends in the tubes. This is before the frame spreaders are added in.

135mm Flyer by Pat Dolan, on Flickr

Spreaders added in and everything brazed or tig welded. The upper frame stay tubes have an added gusset plate to hold it all together. Drops now have axle adjuster tabs installed.

135mm Flyer by Pat Dolan, on Flickr

And here it is, the first 135mm pedal bike frame!

20160623_162839 by Pat Dolan, on Flickr
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
83
california
Here's a cool hub. This is the new 125mm spaced Sturmey Archer S1C, which is a heavy duty single speed coaster brake, mounted into my new frame. I have yet to try this hub out. It will need some development work as my current sprocket adapter main body isn't large enough to adapt to this diameter. Once figured out, though, I think this could become a real coaster brake with enough strength to handle high hp builds. Time will tell. One thing for sure is it's heavy! To me that's a good sign.

135mm Flyer by Pat Dolan, on Flickr
 

zean

Active Member
Dec 5, 2010
321
216
43
california
Excuse me sportscarpat. Will the 135mm or the 125mm hub spacing on your pedal cruiser still have the as perfect as possible chain alignment as you have with your clutch, reduction hub and rear sprocket on your sportsman 200 or the pedal cruiser with the 110mm hub spacing? Thank you sportscarpat for your discipline in figuring out all the details to make a good looking excellent performing motorized bicycle.
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
83
california
Excuse me sportscarpat. Will the 135mm or the 125mm hub spacing on your pedal cruiser still have the as perfect as possible chain alignment as you have with your clutch, reduction hub and rear sprocket on your sportsman 200 or the pedal cruiser with the 110mm hub spacing? Thank you sportscarpat for your discipline in figuring out all the details to make a good looking excellent performing motorized bicycle.
I have the various offsets worked out for proper chain alignment except for the 125mm coaster brake. With this new coaster brake it's more about mounting a motor side sprocket to it than getting the offset correct. It will require an application specific sprocket adapter.
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
83
california
Why braze vs tig the rear dropouts?

Any benefits?
Lots of reasons, actually. I try to keep the old school manufacturing techniques in construction of frames, but this choice was also for ease of manufacture. Since I can score the Worksman INB rear triangle pieces and they are designed as a lug to accept the dropout internally, it was a simple process to design a beefier lug that mounted the same way and since we are in the jig and brazing anyway, we just braze the dropouts, too.
 

zean

Active Member
Dec 5, 2010
321
216
43
california
Excuse me sportscarpat, what is the maximum engine weight and horsepower
that you would fit in your: peddle cruiser, sportsman200, bonneville flyer and keystone flyer. Just asking, do you know the approximate weight of an Indian and Harley single engine from around 1916 or 1912? Thank you for your time sportscarpat.
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
83
california
Excuse me sportscarpat, what is the maximum engine weight and horsepower
that you would fit in your: peddle cruiser, sportsman200, bonneville flyer and keystone flyer. Just asking, do you know the approximate weight of an Indian and Harley single engine from around 1916 or 1912? Thank you for your time sportscarpat.
Good questions, Zean.

What I call the 110mm pedal bike frame (no welded in engine mounts and Worksman INB rear triangle) is the choice for a china two stroke or HF79cc four stroke. I have put GC160's into this frame but feel the Shimano 110 hub, not the sprocket adapter, is marginal at this power level.

135mm pedal bike frame (bigger dropouts and wider spacing for better hubs, still no welded in engine mounts) is good for the GC160. This arrangement can carry the moped type drum hubs and bigger Sturmey coaster brake hubs. Currently there is no available sprocket adapter for the Sturmey hub.

Sportsman 200 has the bigger dropouts to carry the moped hub and has welded in mounts to carry the GX200. Speeds need to be kept within the limits of the tires so a stock GX200 is the engine choice here.

Bonneville Flyer and Keystone use entirely .120" wall DOM tube and H speed rated tires. I have ran over 20 hp in these bikes and upwards of 86 mph.

Vintage Harley and Indian engines are much larger and heavier than the GX200's, although power is similar from what I understand. Personally, I would save the vintage engine for a vintage frame with no structural issues due to it's age or use a modern frame built to the vintage specs.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,337
1,981
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Los Angeles, CA.
I built the 212cc Ruff Cycles bike using the Shimano CB110 hub & the Sportsman Flyer hub adapter & sprocket.
It's still running great & the owner hasn't had any problems with the rear hub.
(I do suggest having the hub disassembled & lots of quality grease added before using it in any motorized application though).

The important thing is to always have a good front brake on the bike.
 
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Mannhammer21

New Member
May 24, 2015
22
1
3
California
Here's what I rode to the shop today. Bonneville Flyer chassis #8. We may stop production of this design at 15 as we have an updated version in the works that will capture what we have learned running the salt flats.

Flyer Factory by Sportsman Flyer, on Flickr

More frames in production in the backround. Looks like the loop down tube is being brazed to the bottom bracket lug.

Flyer Factory by Sportsman Flyer, on Flickr

Here is an adapter plate and sprocket that is going on a rear disc brake hub.

Adapter and Split Sprocket by Sportsman Flyer, on Flickr

Final pick of a Boneville spec chassis that is running a full charging system, battery, and electric starter.

Bonneville #6 by Sportsman Flyer, on Flickr
Bikes look amazing, and very high quality. I myself am looking for a drop loop frame, want to start BTR project and I'm on the look out for some nice frames. I'm curious as to the pricing on the frames you got there If you could get back to me on that that would be great. Keep up the great work, and thanks in advance.
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
83
california
I built the 212cc Ruff Cycles bike using the Shimano CB110 hub & the Sportsman Flyer hub adapter & sprocket.
It's still running great & the owner hasn't had any problems with the rear hub.
(I do suggest having the hub disassembled & lots of quality grease added before using it in any motorized application though).

The important thing is to always have a good front brake on the bike.
Shimano 110 vrs. the Sturmey S1C. There is a big difference between a 110mm and 125mm hub. Bigger bearings and with the added width I don't think coaster brake arm clearance will be a problem.

Coaster Brakes by Pat Dolan, on Flickr

This is the S2C, which is a two speed kick back coaster brake. I see potential with these hubs but need to test them out under engine power first. Of course it means a new design sprocket adapter as the hub (as I recall) is 2 1/4" diameter verses the Shimano 1 1/2".

Coaster Brakes by Pat Dolan, on Flickr
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
83
california
I can see how that would be better for wider frames.
Are you going to make a hub adapter for it?

Keep us posted. (^)
Thinking about it. The hub shell is tapered with a center flat area wide enough to clamp to, but that wouldn't allow side to side adjustment of the adapter body.
 

culvercityclassic

Well-Known Member
Sep 27, 2009
3,115
177
63
Culver City, Ca
Found these pictures on facebook page of Shiny Side Up bicycle show today, Sportsman Flyer's beautiful bikes representing the motor bike world, way to go Pat...must have got a few awards with your display...
 

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