The HF Greyhound Challenge

GoldenMotor.com

MotorbikeMike

Dealer
Dec 29, 2007
477
3
18
Sacramento
Hello, I have read much about many people's ideas about the HF, and even going so far as to call it a "Honda50 Killer", that I am now convinced that the Motor Bicycling community does not know the necessary details, nor have all of the needed experience to recognize which engine will perform better in a Single-Speed Motor Bicycle.

I will now throw my hat into the ring.

I have a HondaGX50HA STOCK in a 26" middleweight bicycle {it will soon be in my new to me (used) Electra} current tires are 26x2 or so Ching Shin City travelers. Primary reduction is first generation Silent Power drive.

I will make available for sale, to anyone within reasonable driving distance from me in Sacramento the following items for use in a build to see on the pavement the true abilities of the Greyhound 79, as compared to Honda gx50 on comparable bikes, similar tires, similar or same drivetrains, and ridden on the same roads.

I can sell you tank with petcock and cap, tires, throttle, Q-matic drive, wide 3-piece crankset, flexpipe, 44, 48, 50 or 56 tooth rear sprocket set, I will help you make an exhaust manifold to fit the HF if you need that assistance, I may even have an old frame to sell, or can get you a new bike if needed! I normally have most of the parts in stock to build or rebuild Cruiser bikes.

I have a motor mount plan that is easy and works well, tho I do not have any HF motor mounts.

The goal here would be to ride stock engines, and do a road test. The only allowable mods to the engine are air cleaner, and exhaust pipe, no porting, no disassembly of engine, pure stock.

No Shiftkits, No mods, just pure stock runs to prove on the road what I already know to be true, and that is a 3600 rpm 79cc 2.5 hp engine, under same circumstances, will NOT outperform a 7700 rpm 2.1 hp 50cc Honda. The proof of the pudding will be when the Greyhound runs out of RPM available and the Honda zips by!

Who wants to play? I can get enough parts together that we could have several Greyhounds for the little Honda to outrun! I do also have HS 50 bike which is an old middleweight and runs well enough to prove it too has what it takes!

Looking forward to meeting my new competitors,

Mike
 

Felton

New Member
Dec 17, 2009
92
0
0
GA
If you mean same gear ratio when you say same drive train, then it wouldn't be a fair fight. I also think you should let whomever takes you up on the offer to disconect the governor, reason being I have not seen one person keep it connected.
 
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glacknoid

New Member
Oct 22, 2008
184
0
0
robbinsdale MN
Will the honda have the gov intact as well, limiting it to 7000 rpms, since there are no mods allowed? When you say similar or same drive trains, are you talking make/model or overall ratio being the same.
 

RusticoRay

New Member
Oct 3, 2009
170
0
0
6mi. from the Old North Bridge
I wish I lived near Sacramento not to build a HF for a challenge just to come by and build a few bikes. I already have my answer in practical application. Put both motors on Sun Atlas 26" Cruiser, Q-Matic, 2.125 tires and a 56 tooth sprocket.The HF with gov removed and flex pipe had plenty of grunt and could pull a house but would not go over 26-28 mph. My weight is around 160lbs. I put the HS motor on my bike because I felt if I could get a cruising speed of 30mph without the motor being peeked I would be very happy. The bike does 32-34MPH and if I lean down I can get another five miles a hour. It cruises at 30 and is at 6500rpm maybe a little more. I dont have a tach or a speedometer thats calibrated just a cateye speedo and a tach, hour counter you attatch to a plug wire. The HF went on a push trailer with a Maxtorque clutch and a 10 inch tire. It would run at 20mph up hill until you run out of fuel and cruise at 29mph again with a cateye on a streetbike.
 

glacknoid

New Member
Oct 22, 2008
184
0
0
robbinsdale MN
Ray: With all that house pulling power of the HF, in your experience, would you say by changeing the pully diameter on the drive shaft to a larger one than what works for the HS engine, you would maintain sufficient torque along with obtaining desireable speed of say upper 30's?
 
Hi glacknoid,

Not sure what you are asking, however the data sheets are from dyno runs. Regular gas [87], stock bore, stroke, wheels, & drive system.

Please note as I have stated before C.I. or CCs aren't as important as motor design. You can tell by the chart my 138 CC Whizzer out performed the B & S Animal, and several Cushmans with much, much, larger motors.

If you want distance numbers, consider this........ My Whizzer [138 CC flathead] traveled 40.3 MPH in 150 feet @8220 RPMs [drag race] and had problems keeping the front wheel on the ground. Ask Jay about it, because he rode it last summer. The same bike with ratio changes won first place again on the dyno [5 years in a row, wanna race?].

The bike attached to the "Roller Road" [calibrated MPH] easily set the record and was a stock 49 CC EZM kit using the Max Torque clutch [we were using belt drive, and Max Torque clutches long before anyone else thought about the idea].

Are you going to CA to race Mike?

Have fun,
 
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MotorbikeMike

Dealer
Dec 29, 2007
477
3
18
Sacramento
HI I just got back from the Gym, and visiting a neighbor who had broken her ankle. I am now seeing the action this thread is receiving, and will now attempt to answer any, and all questions.

Governor can be disconnected, my Honda was the type with stationary throttle, and I removed that assembly externally, and will approve that on any other engine, I consider it unsafe to use a fan-type governor on a MB anyway, and IF you over rev, and blow an engine, it is the owners responsibility.

Drive train: ANY single-speed setup, I certainly do not care what single ratio that you would like to use, I was offering the availability of the Q-matic, BUT you will notice I offered 3 sprocket choices. Use 26" wheels, as we want the results to be as "normal" and "equal" as possible.

IF you choose not to use the Q-matic, then ANY single-speed setup, no CVT, no shifting of any kind, a "Legal" Motor Bicycle.

I will give chances with me on my Honda Silent Power, and the HS Q-matic, currently a prototype model, but I will make every effort to get a production unit on it before the day of the Challenge.

The pic below is my '63 Murray, with the Honda, and Silent Power system, before a 100 mile ride.

Mike
 

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kallsop

Member
May 2, 2009
106
1
18
CT US
Here's my 10 cents of input. The Honda has a wider rev range. If both engine installations have fixed gearing, the Honda will be more enjoyable. With more torque and hp, and minimal weight difference after you add in the rider and bike weight, plus wind resistance, the HF will be quicker if it has the right gearing, but you might have to pedal it up to 15mph before it will pull. I think the HF really has to have a shifter of some kind, otherwise it's operating range is too narrow.
 

RusticoRay

New Member
Oct 3, 2009
170
0
0
6mi. from the Old North Bridge
Ray: With all that house pulling power of the HF, in your experience, would you say by changeing the pully diameter on the drive shaft to a larger one than what works for the HS engine, you would maintain sufficient torque along with obtaining desireable speed of say upper 30's?
Glacknoid, I went with what I had a 2" pulley on the drive shaft. I'm not good with whats on paper kind of a retard with paper formulars can I still use that term on myself. Fossil and KilroyCD could answer that they have put a variable speed pulley on their HF.
I have put a variable pulley on the HS and made many adjustments but no sizeable change in behavior. At least for me not worth the time I spent and the changing the belt for the 2.9" outer diameter.