need some help

GoreWound · Apr 19, 2015

I've got a really fat rear tire, so right now the whole motor and gearbox is way too far to the right hand side just to line it up with the tire.

modifying the drive-shaft from the gearbox would allow me to get the whole engine more centered in the frame.

the motor is currently not mounted in the best way, so I would like to get the driveline lined up with the motor more centered before I finalize the mounting.

Trey · Apr 21, 2015

Gotcha.
Fit, grind, adjust etc, this is what we do.

KCvale · Apr 26, 2015

GoreWound said:
may as well ask this question here.
is it possible to move the sprocket on the output shaft of the transmission?

No, not on the 4G with 100T fixed pulley and freewheel sprocket.

The 15mm output shaft extends 17mm past the bearing before it drops down to the thinner 10.7mm shaft with keyway for the sprocket.

This is what the shaft and bearings inside the housing look like with the sprocket side treaded portion cut off.

And this it mounted.

I have designed 2 new shafts, the standard one is 15mm keyed all the way to the bearing for freewheel 100T pulleys and have a 9T and 10T output sprocket.

The new Grubee 10G's have this design change.

I'll have these for sale this summer along with a 110mm long shaft for direct jackshafting.

For now, all you can do is move the engine, or jackshaft it.

GoreWound · Apr 26, 2015

that shaft and sprocket are a substantially different design to the one I have.
my sprocket has centered teeth, and the shaft has a threaded end for a nut. the keysed section is not stepped down from the rest of the shaft, but the keyway is not cut all the way down it either.
right now what I am trying to do is use a spare sprocket I had from my two stroke engine and a new spacer for the shaft to move the teeth as far as I can (the offset on the 2-stroke sprocket allows me to move it over while still meshing with the keyway.) but for the to work I need a spacer bushing that is shorter than the one that came with it.

in the long run I am considering the 4g unit I have as temporary. I want to be using an X2 cvt for the final build (but that will require substantial re-engineering.)
ideally I do not want to use a jackshaft for simplicity's sake.

Trey · Apr 27, 2015

GoreWound said:
that shaft and sprocket are a substantially different design to the one I have.

Gore- Can you post a couple of close-up pics? I keep going back and forth thinking I understand what you have, but I guess I'm not sure.
I may be of no help anyway, but I've built a few 4-strokes, so maybe.

KCvale · Apr 27, 2015

GoreWound said:
that shaft and sprocket are a substantially different design to the one I have.
my sprocket has centered teeth, and the shaft has a threaded end for a nut. the keysed section is not stepped down from the rest of the shaft, but the keyway is not cut all the way down it either.

That is either the 80 or 100T freewheel pulley then, they have a fixed sprocket for the output.

You can cut that bushing down or just use washers on both sides of the sprocket to get it spaced right and then put the end bolt on.

Good luck using a X2 on that little 2HP HS 142 engine with a 26" wheeled bike.

Besides running backwards they want at least twice the HP the HS has just to function, and meant for turning 14" wheels.

GoreWound · Apr 27, 2015

I have seen those X-2 CVTs on a gx35 and it seemed to work...
also I named the X-2 because I know what it's called, there's another torque converter out there that might work... also my rear wheel is only 20"
pretty sure my 4g is an 80 tooth, it has the open-front cover piece on it.

here's some pics too
first two are the end of the shaft and the sprocket I'm trying to use, third and fourth are the machining fail I found on my transmission, not tightening that belt anytime soon.

KCvale · Apr 28, 2015

GoreWound said:
I have seen those X-2 CVTs on a gx35 and it seemed to work...
also I named the X-2 because I know what it's called, there's another torque converter out there that might work... also my rear wheel is only 20"
pretty sure my 4g is an 80 tooth, it has the open-front cover piece on it.

Yep, the 80T freewheel pulley, it's only 4:1 reduction, but you can position the sprocket as mentioned above with washers.

pics too
first two are the end of the shaft and the sprocket I'm trying to use, third and fourth are the machining fail I found on my transmission, not tightening that belt anytime soon.

Did you orient the offset cam assembly correctly?

Did you install it with the thin part pointing forward to make it easier to dink with the belt tension with the bolts?
Any other position of course won't align up right for adjustment.

What size back sprocket are you using?
A tooth or to smaller 4G sprocket will help, but just a bigger rear sprocket would be better.

GoreWound · Apr 28, 2015

i have a 48 tooth on my rear wheel, the output sprocket on the transfer case is a ten tooth.

the 4g I got was already assembled when it arrived, the thin side of the cam is facing forwards, but if you look close in the third and fourth picture in my last post you will see that the slot for the bolt is not machined correctly, the cam only gets about a couple of degrees of turn before that bolt locks up, so either i run with a loose belt, or without that bolt. (or find a machinist)

as far a tension on the chain goes I have a horizontal rear dropout that has been serving me niceley so far. I should take a picture of it, I have no tensioner on the drive chain right now.

inna coupla days I get some money on hand and some progress will hopefully be made.

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need some help

GoreWound

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Trey

$50 Cruiser

KCvale

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GoreWound

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Trey

$50 Cruiser

KCvale

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GoreWound

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