Scooter/bike hybrid

Joined
Jan 25, 2008
Messages
180
Hey guys,
I'm finally getting started on my motorized bike project.

Bicycle:
a GT Aggressor (I'm sooo aggressive... :???: )

Motor: I'm using a Tanaka PF-4000 that I totally redid,
making about double the power of stock.
(pipe, lowered cylinder, porting, modding and stuffing of cases, bigger carb,
no rev limiter mod) Est about 4 HP.
I'll post picts of the mods if anyone wants to do them.
It's pretty easy to do.
Drive components: I'm using the rear end of a Boxer FS-1 motorized scooter
(spindle drive, with gas tank mounted on the opposite side
as the clutch assembly)

This is almost going to be a bolt on job to my bike.
I just have to mount the rear assembly to the seat post
(I have the remnants of one of those "trail a bikes"
so the linkage is almost made)

The original spindle on the scooter was a .850
and it pulled hard with it. I just took some skateboard wheels, and drilled them out to fit on the old spindle.
I'm going to use set screws in the beginning , and epoxy them on to the shaft once I'm satisfied with their size and gripping ability.


I'm pretty psyched about the project, I figure it will be ready to run by the end of the week.

My only real question is how large of a spindle I should do.
The wheels right now are about 1.6 inches.
I can shave them down easily with a grinder,
so I'll try it like it is first.

What size spindles do most of you folks use?

I had a feeling that around 1.25+ would be fine... but I'll
try the large size first.
I'm looking for speeds about 35ish

Here's a shot of the rear without motor or gas tank....
 

Attachments



L

Large Filipino

Guest
If the spindle seems too large (no power too fast) then you can always enlarge the drive gear...is that gonna be belt drive?
I can't wait to see this thing.
 
U

uncle_punk13

Guest
With my tecumseh 49 cc Island Hopper, 1.5"-2.00" inch diameter drive roller I hit about 25-30. When I had a 1.0" driver I was hitting close to 35 but had very little torque for the hills around these parts, that's why I put the old skateboard wheel on, easier on the tires and the larger diameter gave me better torque... I'd think that with your engine mods and such you may find that where you're at right now with your drive roller is about where you want to be. I dig what you're doing with this set-up so please keep us posted with the details and pic.s
Rif
 
A

Alaskavan

Guest
I agree with Rif. I've been using a 1.5" roller, and 2.3 hp moves it along pretty well. You should be right in the ballpark.
 
Joined
Jan 25, 2008
Messages
180
I'm confused...
From some of your posts it sounds like ya'll are saying that a smaller
drive roller (scrubber) makes you go faster?

That doesn't make sense to me.
In my world of gopeds, the larger the roller, the faster the top speed, but less acceleration.
Isn't that right?

With my tecumseh 49 cc Island Hopper, 1.5"-2.00" inch diameter drive roller I hit about 25-30. When I had a 1.0" driver I was hitting close to 35
If the spindle seems too large (no power too fast) then you can always enlarge the drive gear...is that gonna be belt drive?
 
D

Dockspa1

Guest
It's just like your two sprockets on you single speed bicycle. Bigger back, more torque smaller front, more torque. Smaller Back , more speed, bigger front more speed.
Did I say that right? Ya, I think so.
 
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