Tribrid Project

[Clotho]

Back in 2004 when I built my first motorized bike I played around with the idea of a tribrid for awhile using an electric hub motor and batteries along with the Chinese 2 stroke. (picture 1) I eventually abandoned the experiment and removed the electric parts from the bike because I felt that it didn’t add enough to make it worthwhile. At the time I thought that a generator might work to extend the range but all the ones I looked at were much too big and heavy.

Recently Michigan Mike (thanks Mike!) posted this video in a thread: Hybrid trike. This got me thinking about my tribrid project again. The generator used on the trike is much smaller than the ones I had looked at before. As a result I pulled out the electric hub motor and started work on it again. (picture 2, just a parts mockup at this point) I decided to document this project so I started a blog at Tribridbike.com. I have been writing about my other builds as well so that people can see where I am coming from and what I have done before. I invite you to check it out.

I am rather excited by the possibility of a series coupled tribrid bike. It would make so many thing possible. Unlimited range is one of the most obvious benefits but there are many many more. You could ride away from your home silently and engage the generator when you reach the thoroughfare making your neighbors happy. You can incorporate a sound system using your Ipod. Heck it has a generator. You can pack up your instrument and amp and go play music in the countryside. Or you can use it with your RV and have transportation and a generator with you when you are camping. Ride it to your jobsite and plug your power tools into it while you work!

If you have any other ideas how a bike like this could be used I would love to hear about them.

 

[zero240sx]

I have ordered a 66cc kit from bikeberry and i have an ezip i was wanting to put it on becouse the e-zip has little speed and torque for the hills here in kentucky....so my idea is to have the 2 motors and the wheel all on one chain. i want to use the same freewheel sprocket thats connected to the wheel but i want to make the electric motor sprocket bigger and the 2-stroke motor sprocket smaller to balance the speed of both to be even or really close.
If i leave the electric sprocket the same then it will be able to get me started without peddaling abd get the 2-stroke to start but after 19mph the 2-stroke will have to pull the electric motor and slow it down and maybe even charge it and over charge it.
If i leave the 2-stroke sprocket the same it will accelerate real slow and have too much top speed.
So what I'm trying to say is if i can balance the sprockets to run both motors at 35mph then they can work together until the electric motor starts to die and maybe the gas motor can help charge it back up who knows....not me...until it gets here i guess.
at first im just going to put it all on with the same cogs i guess then go from there.

 

[Cabinfever1977]

the electric motor and the gas motor use diffrent size sprockets and chains.
they will need separate sprockets attached to the wheel together.
the eletric motor will get you up to 15mph for around 5miles,good for starting engine or when you want less noise.you will not be able to run both at the same time as the gas will keep the bike faster then the elctric can keep up with and the elctric would just be spinning but not adding any extra speed or power to bike.you will be able to go uo to 28-30mph with the gas engine,more if you get a smaller rear spocket.

the electric and gas together on the bike will be atleast 100lbs. hope you dont get a flat because you wont be able to walk the bike with a flat.
on my cruiser bike with a flat the tire acually falls right off the rim and makes it hard to walk home to fix flat.

the gas engine wont charge your electric back up much,unless you have a generator on your bike.

 

[Clotho]

Cabin is right. Even with matched sprockets they torque curves for the two motors are completely different so they will only match up in one spot anyways. If you have regenerative braking on your I-Zip then it may be possible to charge the battery while running the 2 stroke. I'm not sure how efficiently this works however.

Some people have found benefit from this setup. One gentleman uses the electric to start the 2stroke. If run on electric or peddling the bike is basically silent so it can be used on bike paths etc.

The downside is the weight. Having the 2 systems on board makes it heavy. My bike will be heavy as well at first but I think I can get the weight down with some work.

 

[Cabinfever1977]

with the eletric it adds around 30lbs to the bike just to use it to start the bike.
i just use my pullstart and no extra weight. the only way i would do both is if i put the gasmotor on a electric bike.how about someone make a electric motor that bolts to where the pullstart bolts too and we could use a small battery and a key switch to start it.

 

[zero240sx]

hey cabin fever that is a great i dea for the electric start... i have the bike on the road now and the electric helps me up to 17 and it helps up hills real well... i have a cut off switch right in front of the seat that cuts the motor off directly. with the 20t sprocket i get 27 on flat... i only have about 35-40 miles on it so far... 250 miles before the gas motor. its awsome... i would probably do it again with the same bike with a lithium ion 30v or 36v.... but im real excited about putting a kit on a normal bike... alot less technical.

 

[squeakmighty]

nice job man!

 

[weekend-fun]

Hi!
I am thinkin about building a tribird too
I got the plans from atomiczombie.com
Also, I attached a pic of another tribird for sale for 50 on c-list
Hope this helps if any want to build one!