HF 2.5 Friction Drive- A Different Approach

GoldenMotor.com

cannonball2

Well-Known Member
Oct 28, 2010
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Colonial Coast USA.
I knew when I bought the HF engine last week I wouldnt be able to leave it on the shelf like I told my wife. Wanted to build a centered rear drive instead of the usual offset. I also wanted to use a Maxtorque auto clutch. So what is happeneing here is the first stages. This is pretty much mock up, the rest of the parts wont be here until Wed/Thurs., so no real dimensions are set yet but it is close. The engine will drive a roller via a belt and jackshaft, the roller(another cheap n easy) will be positioned just ahead of the rear brakes riding on a shaft and two pillow bearings. The engines belt will be a spring loaded idler affair and swapping pulley sizes around will allow me to over/under/1:1 drive the roller. The only engine control will be a throttle and kill. This is more ballanced than an offset, though they are no problem. It sits contentedly on the flimsy cheap a$$ stock stand(gonna change it for sure though) where as the offset motor bike would be on its side. I am interested to see what kind of engeering curves this one will throw. Sorry about the 1 bad pic.
 

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deacon

minor bike philosopher
Jan 15, 2008
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north carolina
I hope your gas tank doesn't leak like mine did but at least yours is level so it will feed. Looks like a good project but I would need a fork lift to get on the bike.
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
I just built a 24" MTB 31cc FD to go on vacation to Fla. It fits easily into my wifes Subaru wagon. Its just so darn cute and light. Rides suprisingly well, pretty smooth even with the knobby tires. Figured if I go to the store with it I will just put it under my arm while I buy stuff.
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
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north carolina
Im thinking about 32cc since i have been riding the ebike which at 24v performs about the same. I like the way feels. I have got rid of all my extra bike frames so I will be looking for frames now as well. The thrift store has been running short on bikes this year. I might have to hit the yard sales .
 

kev1n

New Member
Sep 25, 2009
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wisconsin
I like the way you have the bike setup, looks really reliable and low maintenance. Be careful when getting off the bike, I got a good burn on my right leg from a muffler in that exact location. It's tough to retrain the leg after many years of swinging it over the rear wheel.
Ride safe, Kevin
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
Thanks Kevin, I have just ridden the bike(not running) to get a feel for it, and I became obvious the easiest way to get aboard was to simply step over the bar. You are probably right though, old habits die hard and I ride all summer in shorts. OUCH!
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
FINISHED!! I started messing around with this project on Monday, didnt get the major items like pillow bearings, clutch, jackshaft, etc til Thursday. It has gone much easier than I thought it would. Disassembled and painted it yesterday. Im bad about finishing the utility type bikes and then not taking em back apart to paint them. It has turned out to be very well balanced. The offset engine bikes I have are not at all bad balance wise, but this one is so neutral, you really dont know the engine is there when pedaling. Have to go to a Memorial Day party shortly so the first ride will be later.
 

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cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
Got to ride this thing and all I can say is awsome!! It will pull away from stop and accelerates like a belt or chain drive bike, you are never aware it an FD bike except its so quiet. In fact the engine mechanical noise(valve clatter, they need adjusting) is about all you hear. The China girl muffer is very quiet. Climbs huge hills like a mountain goat. I am slightly underdriven with a 3.25/3.5 pulley combo. I have a 3" pully comming to try which will slightly overdrive it. Its designed so the belt works with either pulley. Top speed calcs. to 28+mph with a 2" roller@ 4800rpm. Smooth, comfortable, and quiet what more could I ask for! Gonna try to get my wife to shoot a vid later.
 

gobigkahuna

New Member
Apr 25, 2011
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E NC
Looked like you just about popped a wheelie when you first released the clutch! Some pretty good torque with that engine eh? Looked like a bit of a hassle to get your leg over it though. Good fun! :)
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
223
63
Colonial Coast USA.
You are very observent. You dont want to grab a lot of throttle if you are standing over the bar, best be on the seat! Its an auto clutch, so its throttle action that gets it moving. Age is the biggest issue getting the leg over, that and short legs.
 

4950cycle

New Member
Sep 8, 2010
111
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Dunnellon,FL.
I like it Ben. I gotta show my take on what you built there. I will send you a pic. I did it back in 95 or so when I lost my DL temporarally. Love the muffler, Where did you get it ? Like to have one for my HF slanty. Oh..and Ditto on the age, step over problem. I'm only 48 and can see it might be a little problem in the future. Step thrue, here I come. Or is it time to register (FL.) the old Puch I have in the barn ?
 
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daRog

New Member
Apr 15, 2011
98
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California
Hate to be the one to kick an old thread, but where'd you get that clutch and how much did you have to spend, cannonball?
 

beltbuckle

New Member
Aug 22, 2011
81
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Meridian, ID
Just a standard Maxtorque, I bought it through a friends business, upper $30s as I remember. I have an extra(belt) one PM me I you need it.
What did you use for the friction drive roller? Is that a part that can be purchased or any details you can provide on that? Looking at doing a similar setup on my recumbent.