FireBelly 4 Stroke "Hard Box" Transmission

GoldenMotor.com

tyrslider

New Member
Sep 26, 2008
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RainCity
Thanks for asking Forbisher.

The Current 1st Edition FireBelly Cycles "Hard Box" limited Edition Hau Sheng Honda Motor Bicycle Transmission weighs in at about 8.5lbs and just under 2" wide.

W/ plenty of opportunities for additional weight savings we've chosen to leave a little extra strength and integrity. Still anticipating a significant amount of weight savings, maybe 1 lb, can be made in the housing. Another .5 lb can be saved in rotating mass.

In escence a lot of hard work goes into these boxes and they are not inexpensive to produce. Inevitably more work cost's more $.

We will not even acknowledge the Hoot as competition. It might just as well weigh 1 lb. It's Cactus!

The Grubee box seems a little hit and miss; they seem to run well for some and not for others.

The Chinese motor kit manufacturers are not really FBC's competitors. In many ways they are the greatest contributers to our business.

FBC will continue to innovate and bring top tier components and products to the discerning customer who understands the price to value ratio and appreciates function and form. We strive to bring quality that is confidence inspiring.

Light weight was but one of many considerations in the design of this product

Forbisher "your" transmission is lighter than the FireBelly Cycles "Hard Box" All Metal Automatic Motor Bicycle Drive System. You must be very proud of your accomplishments; I know I am of mine. Good luck to you in your endeavors.

Thanks again, Evan FBC drn2
 
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abikerider

New Member
Jul 7, 2008
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Sacramento, CA
Hi, I've just finished my first MB build using the Firebelly transmission. Evan was very helpfull in supplying me with parts I needed to make a quality build. Here are some pictures. So far it works great. Still breaking it in and I'll be installing a speedo soon to start measuring mpg and speed.
Mike
 

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Finfan

New Member
Aug 29, 2008
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Tucson, AZ USA
How long before the Firebelly website is going to be on line? I would like to look at these things. Note: I am getting an "Under Development" page when I click the link. I assume everybody else does to.
 

tyrslider

New Member
Sep 26, 2008
958
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RainCity
Hey guys, Thanks for the interest!

We expected to have a smoother transition. We'll be up and going again shortly. We should have the Home page up tomorrow featuring some new items.

Here's a sneak peak at the New FireBelly Universal 4 stroke engine mount

A "Semi" Universal adaptation of the mount seen on the bike below is in the works
That bike also showcases some of the new products and the prototype exhaust tip.

We'll also be offering Delrin Tensioner wheels w/ high speed bearings,
Tensioner kits,
Sprockets and Adapters for Disc Brake Hubs,
Tuneable exhaust for 4 strokes
As always Heavy Duty Wheels and Chains.

We are also working on a couple of complete motorbicycle platforms

Everything We Bring to the Market Place We Bring Because We Feel That It Inspires Confidence and Adds to the Reliability and Enjoyment of the Sportransportivity That Is Motor Bicycling!

Feel free to PM, Email, Call us w/ any questions about motorbicycles, products/prices.

Evan
[email protected]
206 660 2387

dnut
 

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huckersteve

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May 20, 2008
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Seattle
www.gohuckyourself.com
Hi, I've just finished my first MB build using the Firebelly transmission. Evan was very helpfull in supplying me with parts I needed to make a quality build. Here are some pictures. So far it works great. Still breaking it in and I'll be installing a speedo soon to start measuring mpg and speed.
Mike
The bike looks great and so does the paint on that tank! Nice job!!
 

jared8783

New Member
May 13, 2009
216
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Elkhart, IN
Hey abikerider
Nice paintjob on the engine cover and gas tank.

I don't know much about painting.
How do you do it well.

And how did you go about painting the plastic.
 
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mabman

New Member
Oct 4, 2008
258
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In the wind
"About the only thing I wish was different is that that metal transmission gets pretty hot"

Just curious if you think the heat is caused by "I parked it in the sun too long" or a result of drive train friction?
 

abikerider

New Member
Jul 7, 2008
219
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Sacramento, CA
Hey abikerider
Nice paintjob on the engine cover and gas tank.

I don't know much about painting.
How do you do it well.

And how did you go about painting the plastic.
I'm not an expert on painting. I just used a scotchbrite pad to scuff the black paint till it was dull to provide good adhesion for the new paint. I used Duplicolor metalic burnt copper paint from Kragen and just followed the instructions on the paint can, making sure that I didn't put on too much paint at once and cause a run. I applied 3 coats of paint and then a Duplicolor clear topcoat. I let it dry in the sun to speed up the curing process. I did spill some gas on the tank and it did dissolve a little of the clear coat. Hopefully it will become more resistant to gas as it cures further with time. Maybee someone here knows of a good gas resistant clear coat?

For the plastic I used paint for car bumpers from Kragen which uses a special clear primer to insure good adhesion. Once again, I just followed the directions on the can. I really like how it turned out as it is the same color as the engine so the cover just blends right in.
 

abikerider

New Member
Jul 7, 2008
219
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Sacramento, CA
"About the only thing I wish was different is that that metal transmission gets pretty hot"

Just curious if you think the heat is caused by "I parked it in the sun too long" or a result of drive train friction?
Like I said, the heat is being generated by the engine and is being conducted through the metal from the hot engine. I believe there is very little heat generated by the transmission itself since it is so well lubricated. It will get hot even idling in the shade and will stay hot as long as the engine is hot. I wonder if using a proper gasket for the cover instead of just a smear of sealant might slow the conduction of heat. I might give it a try and see what happens.
 

abikerider

New Member
Jul 7, 2008
219
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Sacramento, CA
Ok, Evan and I have discovered the first glitch in the design. In the spirit of openness I will say that the small sprocket on the engine shaft inside the transmission is a small 10 tooth sprocket and does not seem to have enough metal around the collar of the sprocket to be strong enough. This sprocket failed on my transmission but Evan was very responsive to this and has come up with a very good solution of using a larger 12 tooth sprocket to make it stronger. He figured out which sprockets will work to keep the final output ratio about the same and is sending the necessary parts to me as quickly as possible. He has thanked me numerous times for my patience and input and in general I could not ask for a manufacturer more willing to make things right. The construction of this transmission seems rock solid other than this small glitch which will be fixed shortly.

I would also like the warn people that some of these Hua Sheng engines come with a 15mm output shaft. The one I got from gasbike.com has a 15mm ouput shaft and it is more difficult to get parts, like chain sprockets, that fit the 15mm shaft. This has made it more difficult for Evan and I and I would not buy another engine from gasbike.net for this reason alone. If you are going to buy an engine and use the firebelly transmission, make sure it has either a 1/2" or 5/8" shaft and not the odd 15mm shaft.
 

oldcliff

New Member
Feb 9, 2009
64
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Wilmington Ohio
Evan, I am very impressed with your setup. I have been trying to get my 2cycle engine going , (with a SBP jack shaft), and have had little success. The SPB unit is fine, but the engine just won't start. I am losing patience with the 2 stroke China engines. I am ready to bite the bullet and go 4 stroke.

I would like to know what engine you recommend using with your transmission setup. I would also like to know the cost of a complete unit using your exaust and engine mounting kits. If you would please email me this info. Or if you like I will contact you through your website.

Cliff (Retired Chief Engineer Cincinnati Milacron Turning Div.)
 
Hi Abikerider,

We made special spacers to make our drive sytem work on all the different 4 stroke crankshaft sizes. The difference is only .035" divided by 2, therefore the spacer only needs to be approx. .018" thick. We found using .020 shim stock works perfectly because the shafts are actually cut slightly undersize.

For the few considering using the Honda motor with the larger shaft, please consider the extra expense & work needed to make the throttle, governor, and low oil sensor work on a motorized bike.

Recent testing has also delivered some confusing data. In most cases the HS motor has supplied more power than the higher rated Honda motor. The Honda is rated at 2.5 HP, whereas the HS is only rated at 2.0 or 2.1 HP, yet the HS will out-perform in both take off power and top end during recent tests.

Have fun,
Quenton
EZ Motorbike Company
EZ MOTORBIKE COMPANY
 

Dan

Staff
May 25, 2008
12,765
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Moosylvania
For the few considering using the Honda motor with the larger shaft, please consider the extra expense & work needed to make the throttle, governor, and low oil sensor work on a motorized bike.

Recent testing has also delivered some confusing data. In most cases the HS motor has supplied more power than the higher rated Honda motor. The Honda is rated at 2.5 HP, whereas the HS is only rated at 2.0 or 2.1 HP, yet the HS will out-perform in both take off power and top end during recent tests.

Have fun,
Quenton
EZ Motorbike Company
EZ MOTORBIKE COMPANY
Howdy Quenton. Regarding testing. Was this inhouse at EZM or an out side source? (so as I could look it up) Just asking and thanks for your time. I love my Honda but am going HS next build and am curious.

Will post a thread on my exact findings between the 2. The low oil sensor, I have not found it to be a problem but a comfort.
 
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abikerider

New Member
Jul 7, 2008
219
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0
Sacramento, CA
Hi Abikerider,

We made special spacers to make our drive sytem work on all the different 4 stroke crankshaft sizes. The difference is only .035" divided by 2, therefore the spacer only needs to be approx. .018" thick. We found using .020 shim stock works perfectly because the shafts are actually cut slightly undersize.


Have fun,
Quenton
EZ Motorbike Company
EZ MOTORBIKE COMPANY
Hi Quenton, I realize that it can be shimmed but for me this is not ideal. I think a shimmed shaft is not as strong a connection as one that properly fits the sprocket in the first place. I believe bicycle-engines.com sells the Hua Sheng with a 5/8" output shaft. If I did it over, I'd buy it from them.

Also, that's interesting that the Hua Sheng copy seems to perform better than the Honda original. I know I am quite happy with my Hua Sheng engine.
 

tyrslider

New Member
Sep 26, 2008
958
2
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RainCity
Truthfully, if shimmed evenly, there should be no ill effects. Our problem is associated w/ the weakness of the 10 tooth sprocket caused by the groove being cut through the keyway.

I've used 2 different sprockets on my prototype and first production model and neither has broken. My prototype model had a 1/2" bore sprocket drilled out to 15mm and I hand filed the keyway; other than a very sore hand, no problems. The 5/8" sprockets I plugged and drilled out. 2 people have broken those.

The newer ratio employs a 12 tooth front sprocket that is much thicker and also improves clutch engagement. I've sped up the clutch shaft and altered the reduction to the transmission o/p shaft to keep o/a gear reduction virtually the same.

Everyone gets the improved gearing at no cost!

It seems the honda has a higher top engine speed, though.

Thanks Quenton for the input.
 
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To answer a few questions..........

I haven't completed the tests between the Honda & the HS, however after changing to the Honda motor my top end is down 4 MPH. I am using the exact same exhaust, gearing, bike, & carburetor. I have feedback from 4 different users of the Honda & HS motor, and all report the HS to be a faster motor.. Mike [VP of EZM] tested both and reports the Honda is slightly stronger, but he is testing both motors on different bikes.

One of our authorized dealers has made special pulleys & sprockets to fit the smaller shaft, however I am running [and over 30 motors in testing] the smaller shaft with shim stock and I have over 2300 miles on it. The last shipment of motors have the larger shaft, but didn't fit as tight as the motors we shimmed.

Our automatic clutch enguages at approx. 300 to 400 RPMs above idle, and has an un-expected side effect. The clutch [American made] actually works as a motor brake when the throttle is reduced and slows the bike down to aid in stopping quicker. I thought the clutch would "freewheel", but stays connected until approx 15 MPH. Another great side effect of the new clutch is the ability to gear higher [or lower depending on your outlook] and keep the motor from "singing" at higher RPMs. The clutch has allowed me to "cruise" and still be able to take off from a stop without aid of the pedals [slower take-off], whereas the same ratios on a manual require a lot of talent to take off smoothly.

Hope this information is helpful,

Quenton
EZ MOTORBIKE COMPANY
 

tyrslider

New Member
Sep 26, 2008
958
2
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RainCity
I think we both use a Max Torque centrifugal clutch, if I'm not mistaken. I concur what quenton said about the positive side affects of engine braking and such.

One of my customers reports a top speed on the flat of 36 mph w/ honda motor and 44 downhill. My HS is 34 on the flat and 36 downhill, which led me to believe maybe the Honda had higher rpm capabilities. I really have no hands on experience w/ the Honda though.