KC's new 4-stroke Jackshaft base

The 20/80's are 4:1, the 20/100's are 5:1, he will have a 20:90 in the future for 4.5:1 but another new addition coming is a 17/100 with a 5.88:1 reduction and a keyed output shaft long enough to reach the right hand side for direct 'jackshaft' shifting without the other shaft, sprocket and chain.

WAYAFRO said:

Haha I'd love to tell you but I only had .6 hrs on the tach/hr meter when I broke the gearbox and had to peddle home.

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Stage 3 right?

KC I'm wondering if you can tell me if this will mount to my engine, since the ebay seller didn't have much information up and I didn't think to ask?
http://www.ebay.com/itm/400721444538?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT

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Humm, curios..





I don't see how that could bolt to anything, the 4 motor mount holes have bolts and nuts through them to hold the clutch bell.

Perhaps the nuts and bolts are just for the pic to hold the bell in place and that bearing mounted plate just sandwiches between the case and engine, that would be cool if that were the case, a 7G with a better clutch.

That output sprocket also looks to be a freewheel, that could be a good thing depending on the quality.

Best I can do for ya with just those 2 pics bud.

WAYAFRO said:

Got the belt drive today.
Came just as the pictures showed, with bolts and nuts holding it together.

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According to Don Grube what you have is:

• Yes, we know about the Woodpecker T belt drive copy made by a factory called YongQi about 1 hr away from us.. Copy starts with a C and so does China.

And yes you were right it is a freewheel on the output.
I like how it has three holes to adjust the mounting angle.
I just hope it bolts up and I can get everything lined up with the jackshaft.

The clutch doesn't have a key. I hope the one in the stage 3 will be the same size???

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The clutch goes on the engine and NEEDS a key and be the size of the bell, the bell is another story.

It's too cold out to ride right now anyway...well at least something with a motor. (I peddled to the bus stop this morning) It was neg. something today.

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I can relate, 50F after sunrise and 77F this afternoon was just a degree or two short of totally awesome today...
Sorry man, just couldn't help myself ;-}

Which 142F do you have?
long keyed shaft with no clutch, or short shaft with clutch already on it?

Velodrome said:

2 Questions for ya KC.
How close is this to production ( can actually buy )

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Close enough that I just got the first long shaft production design 100T freewheel rear housing and started to mount it into the 4G base I have today.
Heck the bolts aren't even in tight yet but this is how it sits since I called it a day today.





The shaft is supported in the concentric inset by a pair of nice looking Japanese bearings so it will be about how exact the carrier bearing on the right can be, and that will take me as long it takes me my friend ;-}

and do you think the S.A. or Nexus 3 speed hubs could stand up the the MASSIVE power of the HS 49cc ??

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Massive Power (snicker), I haven't been able to break either of those internally geared hubs no matter how much power I have thrown at them.
That does not count the NuVinci hubs but they are not gears, they are CVT and we chewed up 4.

OK, I finally have a window of time to play with the KC's Krusiers 10G long shaft transfer case with the HS 142F tapered short shaft with clutch attached engine it is designed to fit.

The clutch bell is attached to the 10T primary shaft that rides on a pair of bearings.

A 5/8" long shaft HS142 might work if you could find a way to attach a clutch to it and saw off the extra shaft.

The secondary is a big concentric unit for easy belt tightening, with a pair of good Japanese bearings for shaft support, and the 100T pulley freewheels on the shaft so when you pedal you don't have to pull the whole belt and clutch assembly too.

Nice touch eh?
Beats that 7G system to dust.



I am not bound by base bolt holes, it's thick yet soft aluminum so I can orient the shaft wherever I want by drilling new holes so I did one just to see what looks like it might be a good angle.

The shaft is closer to the base and below the oil filler.
It's no good if you can't easily get to your oil filler.


The shaft length looks to be just right, even for really wide bottom brackets.



Keyed shaft and 9T sprocket with 2 set screws.
The threaded hole in the end will make a nice mount for a chain guard disc mounted to the end.
Anything that will keep a pant leg from getting caught in it, that is really REALLY no fun.
Heck, I can even see some sort of 'spinner' bolted on there ;-}

I am using the SickBikeParts BB assembly with a sealed bearing 3 piece crank cartridge, HD freewheel with coupler for the sprocket pair so any wide enough crank arms can fit it.

Primary sprocket is 48T, secondary back wheel drive sprocket is 30T.

Output shaft is 15mm so I will playing with this 15mm pillow that is on it's way first to at least let me visualize how I am going to make an adjustable carrier bearing support on the base.



All I know is has to be stronger than my first attempt a year ago.



That attempt did pave the way for my new custom made base that is actually easy to work with and does the job.

Trail and error if need be, but I have a pretty darn good plan for what I want, a single drop in 4-stroke unit with right side drive.

Gear ratios:

The centrifugal clutch kicks in ~3500 RPM.
Max torque is ~4800-5200 RPM.
Max power is at ~6800 RPM.

With this 7-speed derailleur 1st is a 21T sprocket, 7th is a 12T.

Final drive ratio to the back wheel sprockets is 24.44 x (30T / Teeth on back sprocket), a decimal number.

@4KRPM 1st will do 17.5MPH
@4KRPM 7th will do 31.5MPH

Ideal easy RPM

@5.2KRPM 1st will do 23.5MPH
@5.2KRPM 7th will do 41MPH

Open it up to MAX power sweet spot

@6.8KRPM 1st will do 34MPH
@6.8KRPM 7th will do 53MPH

Those are of course all math numbers that does not account for weight or wind resistance, but an ideal drive reduction to the primary rear drive sprocket.

That's it for now, I need some flat metal strong enough to hold the structure and retain it's lines, but easy enough to cut and bend with simple tools to make a mock up.

OK, reality time...

Just suffice it to say I scored on getting a bunch of great transfer case parts, some of which I helped design, on a pallet just for me from China to custom assemble some top quality units to fit your gearing needs and set the bar back up high where it should be for such an important part of a 4-stroke drive train.

Why the heck not right?

I have spent a couple of years trying everything I can to come up with what I know will work the best for the 142F and 144F engines on a bike.
The 144 is the 53cc version of the 142 but compatable.

I am going to start with 30 custom modified 4G bases with dual bearing support for each side of the T-belt transfer case, and then an array of different part options of it's internal and external reduction and size.

In short the drive train options and mounting base I have worked a long time to come up with for my own builds I will be offering for sale in a custom way.

I don't know the exact date the slow boat from China sails with Dons 20' cargo container, all I know is he will put a pallet of what I want on it to hitch a ride to the states and I'm going to give this new gig a try.

One thing you will never lack from what I sell is on-line tech support.
Heck my web site is already geared for that and I have time to help anyone looking to go 4-stroke by their actual bike.

Anyway, I think it's a needful thing for those that aren't worried about every penny and just want to build something reliable, kind of my like my full build customers.

Thoughts?

... other than cost, dates, etc... I just don't know that yet, I am just probing interest in the concept and their intention to actually buy one.

Thanks guys, it's a big step for me.