Sixthreezero Cruiser Bike W/Massive Mid-Frame Space!

5-7HEAVEN

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Aug 2, 2008
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https://sixthreezero.com/collection...ero-in-the-barrel-21-speed-beach-cruiser-bike


Well, I spent my stimulus check! I just received my new Sixthreezero 21-speed cruiser bike through Amazon yesterday. Shipping was quick and cheap($15.00) It has cantilever brakes front and rear. With the exception of disc brakes and suspension fork, it has everything I searched for. It has a 14t-28t 7-speed Shimano cassette and derailleur, which should work fine to channel the engines' power.
The midframe is FIVE INCHES! wider from head tube to seat tube than the new Diamondback cruiser frame I was going to use. I'm trying to mount two pocket bike engines at an angle so they look like a "V-twin" engine. This bike is 4 inches wider at the Diamondback's mounting plate position, so I should be able to able to fit the "V-Twin" or tandem-mounted Tanaka 47R engines. Fully functional pedaling too.

It took years of searching to find a bike like this. My single-engine Diamondback mountain bike has me tiptoeing at a standstill. This bike is almost 5" lower to the ground, so I can stand flatfooted at a stop.

It's important for short-legged senior citizens like me to have solid footing.
 

Citi-sporter

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Jun 16, 2014
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North Bend, Or,
https://sixthreezero.com/collection...ero-in-the-barrel-21-speed-beach-cruiser-bike


Well, I spent my stimulus check! I just received my new Sixthreezero 21-speed cruiser bike through Amazon yesterday. Shipping was quick and cheap($15.00) It has cantilever brakes front and rear. With the exception of disc brakes and suspension fork, it has everything I searched for. It has a 14t-28t 7-speed Shimano cassette and derailleur, which should work fine to channel the engines' power.
The midframe is FIVE INCHES! wider from head tube to seat tube than the new Diamondback cruiser frame I was going to use. I'm trying to mount two pocket bike engines at an angle so they look like a "V-twin" engine. This bike is 4 inches wider at the Diamondback's mounting plate position, so I should be able to able to fit the "V-Twin" or tandem-mounted Tanaka 47R engines. Fully functional pedaling too.

It took years of searching to find a bike like this. My single-engine Diamondback mountain bike has me tiptoeing at a standstill. This bike is almost 5" lower to the ground, so I can stand flatfooted at a stop.

It's important for short-legged senior citizens like me to have solid footing.
I know this thread is over a half year old but I've been looking at SixThreeZero bikes and their long frames do seem ameniable to mid mount engines of larger size. The top tube's diameter also says to me it could become a fuel tank, if I trusted my TIG welding skills. Sadly I have far too many project bikes.
 
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5-7HEAVEN

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Yes, I guess the top tube could be used as a fuel tank. 32oz. might fit in there.

I’m still working on this 212cc engine installation, even though it’s an old thread.

I didn’t go for a simple rear wheel hookup.

I’m going to use a shift kit, with no jack shaft.

Engine power is being sent directly from the clutch to the bottom bracket.....

and the pedals will still work!

It’s extremely complicated.
 
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Citi-sporter

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Xtreme Power still sells their Lifan 79 cc engine through Amazon for about $120. 2.5 HP is all the power I'd trust into a bicycle drive train, and even then I'd be very careful about start-offs and powering up hills. I been thinking about the series 30 CVT in conjunction with the little sub 100 cc 4 strokes.
 
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5-7HEAVEN

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My engine is Extreme Power Lifan 212cc.

Yes I intend to drive with caution.

It’s not about using power to go 50mph.
It’s about traveling on the flats and the hills effortlessly.

Like motorcycles and cars. They can exceed 100mph, but you don’t have to.
 
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Citi-sporter

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Oh! OK I see what you're doing, you're basically using your own human interface governor keeping the 212cc engine low speed/low power? That would keep the stress lower. I have a Volvo 850 turbo it's auto transmission locks up at 47~50 mph and on the flat, if you keep it right at 48 to 53 it will get nearly 40 mpg. This car is capable of way over 100 mph.
 

5-7HEAVEN

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Oh! OK I see what you're doing, you're basically using your own human interface governor keeping the 212cc engine low speed/low power? That would keep the stress lower. I have a Volvo 850 turbo it's auto transmission locks up at 47~50 mph and on the flat, if you keep it right at 48 to 53 it will get nearly 40 mpg. This car is capable of way over 100 mph.
Exactly!

Even though my car can go 100mph, I've never been over 75mph.

Extra power is for short bursts, while still below the speed limit.

I fully appreciate the extra torque on steep hills.
 
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EZL

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May 13, 2016
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Chenoa, Illinois, USA
Yes, I guess the top tube could be used as a fuel tank. 32oz. might fit in there.

I’m still working on this 212cc engine installation, even though it’s an old thread.

I didn’t go for a simple rear wheel hookup.

I’m going to use a shift kit, with no jack shaft.

Engine power is being sent directly from the clutch to the bottom bracket.....

and the pedals will still work!

It’s extremely complicated.
I've had thee Sixthreezero extended wheel base model with the 212cc engine and the CVT on it for over 2 years with no problems with the frame.
Forget about using the in-barrel cassette on a ManicMechanic hub coupler, the small bearings on the hub won't take the power. I had to go to
magwheels with sealed bearings in them and after that never had any problems. I did not mount the ending vertical since I didn't trust the
torque the engine would develop on the seat post. I have enough room to put a electric starter on the engine and a charging system. I would
not even think of a full power start from 0-50 mph on this engine the torque is way too much for a bike and the bike will lift the front wheel
on a moving run with 3/4 throttle where you have to lean forward to keep from hooking up too much. You put a 212cc on the bike and you
want to baby it since it can get away from you. Don't put this engine on a bike unless you have experience with motorcycles. The 212cc is
good for cruising and even pulling trailers.
 
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EZL

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May 13, 2016
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Chenoa, Illinois, USA
That Lifan probably has a transmission that is geared? I know the Lifan 125cc has a transmission and that would be a good setup on a bike
as long as you have the room for the engine.
 

5-7HEAVEN

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No, this Lifan is the 212cc clone.

I intend to treat it with great respect.

EZL, did you weld the motor mount or brace the frame?
 
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EZL

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Chenoa, Illinois, USA
No, this Lifan is the 212cc clone.

I intend to treat it with great respect.

EZL, did you weld the motor mount or brace the frame?
Not yet, I ran out of oxygen for the brazing torch and I mean to weld a plate into the frame. The 212cc engines like to break things
but they are good for road use. I'm running a real Japanese VM22 Mikuni carb on mine with the governor removed along with the
low-oil sensor removed. The factory carburetor on the 212cc engines are junk compared to the Mikuni. I did try the Stage 1
setup on the factory carb and used it for one season then switched to the Mikuni and the performance/reliability is far better.
The CVT is the kit one and the only problem I've had with it is the webbed belt will tend to stretch and loosen up over time.
I need to order a few more belts and I suspect they do wear and stretch due to pulling a trailer. I doubt if there's a hill that the
bike can't accelerate up even pulling a trailer. I'm sure you will be satisfied with the 212cc engine on the bike.

You can get an extended engine mounting plate channel for the SixThreeZero extended frame bike that can use the GasBike
aluminum CNC mount for your bike from: MBRebel.com

Note, I believe she is the only one that has it available for this bike and it costs with shipping about $30.00. I would recommend
hogging out the slots a little on the channel so that the hardware can be used on the mount. I have not had any problems with
the mount using the CNC mounting hardware. The CNC mount and engine plate will also work with the 79cc Predator engine.
 

5-7HEAVEN

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Thanks for the input, EZL.

What’s your gear ratio?

I’m not using CVT.

I have a 23t timing clutch, belted to a 150-tooth pulley on the bottom bracket.

Instead of the standard left rear wheel sprocket, I’m running engine power through the bottom bracket to the right side.

And keeping the pedals working.

Like a shift kit to the 34-14 cassette.

Thanks for the tip on the weak rear hub.

I might use mag wheels I
 
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EZL

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May 13, 2016
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Chenoa, Illinois, USA
Thanks for the input, EZL.

What’s your gear ratio?

I’m not using CVT.

I have a 23t timing clutch, belted to a 150-tooth pulley on the bottom bracket.

Instead of the standard left rear wheel sprocket, I’m running engine power through the bottom bracket to the right side.

And keeping the pedals working.

Like a shift kit to the 34-14 cassette.

Thanks for the tip on the weak rear hub.

I might use mag wheels I
I would run Mag wheels since the rims use sealed bearings and can take the torque. The rear sprocket on mine is a 34-tooth
and the CVT is a game changer since the torque range is pretty uniform across the rpm band. The acceleration is wicked and
can throw you off the bike if you aren't watching the throttle. The CVT is not a standard CVT like what is used on the minibikes
since it's output shaft is extended and really should be a 3/4" instead of a 5/8" shaft. The CVT is a little small for my engine
since the addition of the Mikuni carb on the engine and low restriction muffler. I tried a 20-tooth sprocket on the bike and the
engine slipped the belt driving the CVT so the engines puts out a lot of torque. I'd like to try a Lifan 125cc with the manual
transmission since it would be quieter and gives a person a better selection of gearing. The SixThreeZero has overkill space
for the 212cc and I'd like to see how much space would be required for the 125cc Lifan? One gripe with the CVT is it takes a
lot of room so the pedal shaft has to be long and the arms heated to get more offset. Pedaling the bike is a workout and the
only real way would be to remove a masterlink on the drive chain, remove it to pedal the bike since the CVT would add some
drag to it. The bike is not meant to be pedaled like a motorcycle! I still would like to try the Lifan engine on the bike but $$$
stop me until I can save up enough for one. The CVT is also somewhat noisy since the front drive clutch and a pin will rattle
much like the clutches on the 49cc 4-stroke systems. You will not be able to quiet the engine's exhaust since it is fairly loud
even with the stock muffler on the engine. One plus with the CVT is that the bike really coasts good when the cogs in the rear
drive release at a certain rpm. I noticed using a 36-tooth sprocket the CVT does not coast as much and I'd bet a lower ratio
would even be worse. A 36-tooth just gives too much torque to the rear wheel and could get away from you if you aren't
watching how much throttle is used. A 30-tooth might be the best for cruising...
 
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5-7HEAVEN

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Thanks for your input.

I’m praying that my 212 engine doesn’t destroy my driveline.

I think my gearing will be fine.
First gear will be 9.24:1.
If that’s too low, Second gear is 6.52:1.
Sixth gear to be 4.35:1.

Easy does it.