79cc Sportsman Flyer build

Tom from Rubicon

Well-Known Member
Apr 4, 2016
2,026
4,290
113
70
Rubicon, Wisconsin
This is where I started. (68) Bike builders that have machine tools/shops | Motorized Bicycle Engine Kit Forum (motorbicycling.com) Most of the photos are there.
Inspired by the brake arm anchor of the 1914 model 10F HD, yesterday i did the layout work on a block of 6061.
Today, I set up the block in the Bridgeport vise, using an edge finder I established the center line. From the end of the block, finding the edge, moved in 5/8" set zero in X and Y of the digital read out. the 5/8" move was to generate a 1/4" web.
Center drilled and then drilled thru 1/2" dia., followed by a 3/4"dia. end mill through the block. The 3/4" bore matching the 3/4" dia. of the chain stay leg. I calculated in an excess amount of material.
You can take it off but you can't put it back on.
Unless you are a good welder. Another digression. Early in my apprenticeship I was turning a piece in a lathe. my measurement was off by ten thou. so I dialed in another ten and the [email protected] thing got smaller.
The brake arm hanger cannot be centered to what I am making unlike the 10F. The Flyer chain stay tube is pinched and swells to hold the axel hanger. This whole exercise was to eliminate the usual hanger strap.
Wonder why I drink?
1914 Harley-Davidson Model 10-F Twin - National Motorcycle Museum (nationalmcmuseum.org)

Done finally, some tweaking to do but nothing major.
Tom
 

Attachments

Tom from Rubicon

Well-Known Member
Apr 4, 2016
2,026
4,290
113
70
Rubicon, Wisconsin
Thanks guys ,
I got the weekend to sort the imperfection (anchor radius's are slightly smaller than the chain stay diameter).
So I have to turn a mandrel to slightly open up the brake anchor.
The 1/16" gap between half's will provide all the draw wanted. I knew draw up was going to be trying. That said I wanted to give it a go. Caveat. Never discount a brain fart. Wasn't the beer. I could perform brain surgery after a few. Brag? Nah!
So goes the rest of the story. Fit problem, see above. Where there is a will Archimedes leads the way.
But my axel nuts were not tightened, so as the brake anchor drew up it tightened a nicely slack drive chain.
I have lost so much riding time this year and days are getting shorter. Some birds have stopped singing.
The molt has started to renew flight feathers. Sposed to be a wet weekend. Wish me luck.
Tom
 

Tom from Rubicon

Well-Known Member
Apr 4, 2016
2,026
4,290
113
70
Rubicon, Wisconsin
Thanks guys , your kind words are warmly received.
I got the weekend to sort the imperfection (anchor radius's are slightly smaller than the chain stay diameter).
So I have to turn a mandrel to slightly open up the brake anchor.
The 1/16" gap between half's will provide all the draw wanted. I knew draw up was going to be trying. That said I wanted to give it a go.
Caveat. Never discount a brain fart.
Wasn't the beer. I could perform brain surgery after a few. Brag? Nah!
So goes the rest of the story.
Fit problem, see above. Where there is a will Archimedes leads the way.
But my axel nuts were not tightened, so as the brake anchor drew up it tightened a nicely slack drive chain.
Think adjustability, always.

I have lost so much riding time this year and days are getting shorter. Some birds have stopped singing.
The molt has started to renew flight feathers. Sposed to be a wet weekend. Wish me luck.
August has the Puff Ball Moon, for those that like them.
 

Tom from Rubicon

Well-Known Member
Apr 4, 2016
2,026
4,290
113
70
Rubicon, Wisconsin
More tweaking. I could have sworn the brake arm was centered perfectly to the chain stay. That fantasy went out the window. It was not an easy assembly yesterday, but it did assemble. Some of which I attributed to the anchor radius being .005" smaller than the chain stay. Today I turned a steel bar .006" larger than the chain stay. Drew the assembly on the sizing bar and clamped the assembly in the mill vice multiple times while also drawing up the clamp bolts.
When I got as much as the vise would give I sat a 10# steel master flat on my 100# anvil the sizing bar drawn between the brake anchor halves and wailed on with a 2# nylon faced dead blow hammer.

Brake anchor now fits the chain stay with just a bit of slip. Perfect. That's when the imperfect brake arm geometry became easy to see. So I grabbed an adjustable spanner and sprung the brake arm a bit so it sort of lines up with the anchor slot, but at an angle. Brake arm tweaking next.

Glad some poor bugger isn't paying me to do this.
Tom
 

Tom from Rubicon

Well-Known Member
Apr 4, 2016
2,026
4,290
113
70
Rubicon, Wisconsin
Something of note not mentioned in my last wordy post, and I took into consideration. Unlike ferrous and most non ferrous metals. Aluminum has very little spring back when deformation is applied. I counted on that property.

TECB, I beg to disagree.
Had I from the get go, just purchased a Sportsman Flyer 80 directly from Pat Dolan, this thread would not exist.
Start at post #1. Pat knows why and how i got started and has done right by me.

What has allowed me as needed to diverge from stock parts is a fully equipped home machine shop. When you are at the mercy of vendors, caveat emptor.
Your complaint is noted and right in what can be got from low cost vendors. On the obverse, the racing go kart guys produce stellar product
Tom
 

Tom from Rubicon

Well-Known Member
Apr 4, 2016
2,026
4,290
113
70
Rubicon, Wisconsin
Hey Rick, haven't seen you on my radar for awhile. Weather coming off the Gulf, without a hurricane is breaking our drought.
Mona and I went snooping down Oconomowoc today. The rain we got Saturday was not historic.
But for awhile rain came down like a double vulva cow peeing on a flat rock. In some fields corn is dead, not fit for silage.
Though year.
Tom
 

indian22

Well-Known Member
Dec 31, 2014
4,196
5,930
113
Oklahoma
Right Tom the forum engine has a habit of not flagging certain threads that I follow. Today it hit. Nice machine work on the Sportsman.

Weather here is atypical as we've had rain all Summer with a couple of inches late July an early August. It's a also been rather cool all Summer with a few high 90's like today's forecast. I hate it when you guys up North get these abnormal weather patterns that are actually the norm here. Natives are used to it, but those that transfer in have a hard time adjusting.

Glad to hear it's easing up and you guys are getting out together for sights and shopping.

Rick C.
 

fasteddy

Well-Known Member
Feb 13, 2009
6,912
3,403
113
British Columbia Canada
Finally received rain here Friday night into Saturday and some on Sunday. No rain on the Wet Coast for 51 days and temperatures in the 80's and 90,s with a few days at 108F. Today it 64F at 10am.

Forest fires raging all over British Columbia and one of them is threatening a large city about 6 hours East of us.

Steve.
 

indian22

Well-Known Member
Dec 31, 2014
4,196
5,930
113
Oklahoma
Steve 51 days without rain in Pacific N.W
Is that a record? 108 is very uncommon here in the arid belt of Western Indian Territory though drought conditions unfortunately quite common.
I've read that Alberta and even Saskatchewan provinces are affected as well?

Rick C.
 

fasteddy

Well-Known Member
Feb 13, 2009
6,912
3,403
113
British Columbia Canada
Hello, Rick,
Beef, grain and dairy producers In Alberta, Saskatchewan,and Manitoba our entire mid West are in desperate trouble. Crops are knee high and burnt up by the sun. I think Ontario the province next to Manitoba going East is in poor shape as well.

Salmon in British Columbia are not doing well with the warmer waters and there is die off of the young fish in the rivers where they live before they head to the sea to live only returning to the same river or stream to spawn.

Many heat records broken here in B.C. and at last count that I heard it was 59. I believe it is a record for no rain. No rain in the near future so they say. We'll have to see what the winter brings up here for snow and how long it stays on the mountains before it melts.

Steve.
 

curtisfox

Well-Known Member
Dec 29, 2008
5,512
2,417
113
minesota
we have had the same, un watered fields about the same, except down Mpls and below. Seems like all the rain is going from us down and east. What is going on now tornadoes in Wis. and over east. We usually get that weather first of June, its's like you can't have that heat without a storm coming, starting to get that way, like you say winter will tell the story............Curt
 

Tom from Rubicon

Well-Known Member
Apr 4, 2016
2,026
4,290
113
70
Rubicon, Wisconsin
Tweaking on Sunday, got the brake arm mounting point centered with the slot in the anchor but the blasted B.A. refused to slip into the mounting slot.
I am known for building the boot that kicks my arse. (^) Slot was too fn' tight kind of on purpose. Bad idea.
But a feeble light came on in my thick skull. Think like a M1911 Colt. M1911 pistol - Wikipedia Loosen the tolerance's.
Today, beer and a half. Opened up the B.A. hanger slot from 1/8" to 3/16". Back on the bike and we are off to the races.
Fifty years of striving for perfection and this bloody machine likes some Farmer make do. Fitting I suppose.
I am a Farmers son.
Supposed to be wet again Tuesday. Got to remember to oil this fresh engine. Chains are waxed.
Tom
 

xXNightRiderXx

Active Member
Jan 12, 2017
499
209
43
Boise
Right Tom the forum engine has a habit of not flagging certain threads that I follow. Today it hit. Nice machine work on the Sportsman.

Weather here is atypical as we've had rain all Summer with a couple of inches late July an early August. It's a also been rather cool all Summer with a few high 90's like today's forecast. I hate it when you guys up North get these abnormal weather patterns that are actually the norm here. Natives are used to it, but those that transfer in have a hard time adjusting.

Glad to hear it's easing up and you guys are getting out together for sights and shopping.

Rick C.
Personally, living in a desert around the same altitude as Vegas, it's nice getting those abnormal weather patterns. Even though I live right on the edge of the desert and forests, the climate border is real. I miss the rains and humidity of Washington. I remember it being so much easier to breathe in the warm weather. It's my birthday in a couple days, and I'm goin out on a mtb ride. Biggest I've ever done. And it's going to be in the north, where it's not quite as dry and trees are abundant.