Thinking of converting a 4 stroke mount to an adjustable 2 stroke mount. Anyone ever try this?

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CycleRyder

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Jun 23, 2017
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I was thinking of fabricating my own adjustable 2 stroke mounting plate to save money because the adjustable CNC mounts are pretty pricy. The motor I'm getting is the Skyhawk GT5A 66cc. The front mount is I think 1.5 inches & the rear I think is 1 inch. The tools I got allow for cutting & drilling but thats about it. Cant really weld because I don't got a welder. Don't know the exact distance of both front & rear motor mount studs of the GT5A yet but I'd imagine it would be at those measurements or a little past those measurements.

Could the mounting studs be placed through the slots of a 4 stroke mounting plate? It seems like they could but looks can be deceiving as I have learned the hard way in the motorized bike hobby. I plan to cut the 4 stroke mounting plate in half & drill some holes for U bolts to attach it to the frame & rase the motor mount plates above the U bolts & U bolt plates with bolt collars & another metal plate under the slotted mounting plate halfs. If this is possible I'll post pics when the project is done. I'm getting the motor & parts to get it up & running in a few weeks & plan to get the U bolts & stuff from my local hardware store if they got the sizes I need.
 
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crassius

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I'd probably try some 3 inch wide 1/4 inch thick steel and bend it to look like this \___/ then put two holes in front and back to bolt motor to
 

CycleRyder

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I'd probably try some 3 inch wide 1/4 inch thick steel and bend it to look like this \___/ then put two holes in front and back to bolt motor to
Looks like a neat idea but wouldn't that place the motor at an odd angle? Looks like the carburetor wouldn't be leveled right. My idea is to keep the motor mounts at or close to where they are supposed to go on the frame while being adjustable from side to side.

I wanted to try using a 4 stroke mounting plate because I already have one from an old build & all I would have to do is cut in half & drill a few holes. Bending 1/4th inches of steel sounds like it would be pretty tough to do. I'm going to attempt to mod the 4 stroke mounting plate but if that don't work out I'll try your \__/ idea.
 

crassius

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all depends on how much of a bend you put in (here, I had to take whatever ascii would give me)
 

CycleRyder

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Got a pic of the frame the way is stands now?
No but its the standard beach cruiser frame style with the 1.5 down tube & the 1.0 seat tube. Best part is it's a steel frame so it should be able to handle any motor or mounting setup for thousands of miles.
 

CycleRyder

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Here's an easy way. Buy this and bolt it directly onto your 4-stroke mounting plate:

http://www.ebay.com/itm/80-cc-motor...134004?hash=item2112c9c5b4:g:l7IAAOSw-jhUH2PR

Slotted bolts for this mount's adjustments, of course.
That probably wont fit the front clamp of the Skyhawk GT5A motor. Looks like a simpler idea just probably wont fit my motor mounts because it looks like it was designed more for the generic 2 stroke motors with the front & rear mounts built for 1 inch seat & down tubes.

The Skyhawk GT5A I'm getting has the 1.0 seat tube 1.5 down tube mount setup from the looks of it & I wouldn't trust using rubber mounts to adapt it to that OCC chopper mount. When I install a motor I never use rubber in the mounting clamps. Causes the motor to vibrate more putting stress on the parts that can lead to serious engine failure.
 

CycleRyder

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Why not just cut the 4-stroke base off and install the 2-stroke normaly?
I plan on using wider tires to make metal bridge crossing safer & more comfortable. Also wider tires should handle rough roads around here a little better than thinner tires. Mounting the motor the standard way wont allow for proper chain clearance with a direct drive. I know a jackshaft kit could be a solution but I don't want or need a jackshaft kit because my bike doesn't have gears. I pan on using 3 maybe even 4 wide tires on my bike just haven't decided what tread pattern I want yet. Between flame or semi slick streets if I can find them.
 

KCvale

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Feb 28, 2010
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I know a jackshaft kit could be a solution but I don't want or need a jackshaft kit because my bike doesn't have gears.
Well.. you can always change out your back wheels hub for an internal shifter, and then jackshaft for 3" tires...



3.75" tires...



And though that is a 4 stroke engine, the principle is the same, if you can pedal it, that's where you want to add engine help, especially if you drive 4+" tires.



Fat tires, gears, and disc brakes rock.
 

CycleRyder

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Well.. you can always change out your back wheels hub for an internal shifter, and then jackshaft for 3" tires...



3.75" tires...



And though that is a 4 stroke engine, the principle is the same, if you can pedal it, that's where you want to add engine help, especially if you drive 4+" tires.



Fat tires, gears, and disc brakes rock.
Those are some nice builds. I have been thinking of getting an internal shifter wheel. Know where I'd be able to get a good one? Hoping to spend no more than $50 on a wheel. I was also looking at getting the sick bike parts 2 stroke shift kit which turns out costs less than I thought although it would require me to swap out my stock GT chain ring for the jack shaft chain ring but if it means wider tires I'm open to the jackshaft kit option. But the cheap near term solution I'll have to try offsetting the motor by an inch or so which is possible with a slotted platform on the front & back mounts of the motor & U bolts to hold it to the frame.
 

KCvale

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Feb 28, 2010
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Those are some nice builds.
I have been thinking of getting an internal shifter wheel.
Know where I'd be able to get a good one?
Hoping to spend no more than $50 on a wheel.
Here is a new matched set with 3-speed internal rear for $150

http://www.americasbikecompany.com/...MI2_65uuWf1QIVEbnACh2DaQZcEAQYASABEgKcGfD_BwE

That's the cheapest way to go new if your frame has V-brakes but crappy otherwise, it has a coaster brake that is rendered useless with the jackshaft, you can't pedal backwards.
Well you can, but it just freewheels, that is what allows your pedal chainring to spin at insane speeds and not beat your legs to death.

You can probably find a 3-speed bike on your local craigslist.org web site to get wheels from, I don't know, I custom build for customers and use noting but brand new parts which explains why my bikes look the way they do, the good new stuff costs good money, but for your own ride you can use anything ;-}
 
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CycleRyder

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Jun 23, 2017
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Here is a new matched set with 3-speed internal rear for $150

http://www.americasbikecompany.com/...MI2_65uuWf1QIVEbnACh2DaQZcEAQYASABEgKcGfD_BwE

That's the cheapest way to go new if your frame has V-brakes but crappy otherwise, it has a coaster brake that is rendered useless with the jackshaft, you can't pedal backwards.
Well you can, but it just freewheels, that is what allows your pedal chainring to spin at insane speeds and not beat your legs to death.

You can probably find a 3-speed bike on your local craigslist.org web site to get wheels from, I don't know, I custom build for customers and use noting but brand new parts which explains why my bikes look the way they do, the good new stuff costs good money, but for your own ride you can use anything ;-}
My cruiser uses a coaster brake so my rear brake would be rendered useless with that wheel. I might stop by my local bike shop & see what they got. They ususaly have pretty good quality bike hardware. Might try getting a shifter hub & build my own custom wheel around it that can also work for my coster brake or figure out how to mount V brakes to it if I cant use a coster brake with a shifter hub.
 

5-7HEAVEN

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Aug 2, 2008
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That probably wont fit the front clamp of the Skyhawk GT5A motor. Looks like a simpler idea just probably wont fit my motor mounts because it looks like it was designed more for the generic 2 stroke motors with the front & rear mounts built for 1 inch seat & down tubes.

The Skyhawk GT5A I'm getting has the 1.0 seat tube 1.5 down tube mount setup from the looks of it & I wouldn't trust using rubber mounts to adapt it to that OCC chopper mount. When I install a motor I never use rubber in the mounting clamps. Causes the motor to vibrate more putting stress on the parts that can lead to serious engine failure.
The operative word is "probably" until you contact the vendor for pertinent information.

I guess a metal sleeve wouldn't work for you.
 

5-7HEAVEN

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Aug 2, 2008
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My cruiser uses a coaster brake so my rear brake would be rendered useless with that wheel. I might stop by my local bike shop & see what they got. They ususaly have pretty good quality bike hardware. Might try getting a shifter hub & build my own custom wheel around it that can also work for my coster brake or figure out how to mount V brakes to it if I cant use a coster brake with a shifter hub.
They make IGH with coaster brakes.
 

curtisfox

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Dec 29, 2008
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I have a Sun cruiser bike, has 3 speed hub with coaster brake. It is a nexus hub, i have been pedaling it for 10 years and still works good.......................Curt
 

KCvale

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Feb 28, 2010
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I have a Sun cruiser bike, has 3 speed hub with coaster brake. It is a nexus hub, i have been pedaling it for 10 years and still works good.......................Curt
Yes, most IGH have a coaster brake, the disc brake option costs more, the thing is, with a jackshaft pedaling backward does not move the chain so a coaster brake is useless.
 

curtisfox

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Dec 29, 2008
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That bis right, the IGH is not the best for gears anyway. You have to back off the gas to shift, and are easy to destroy if not taken care of, or done right. His best bet would be cantilever brakes or V brake with multi speed hub ........................Curt