Combined mtr-mount & jack shaft

GoldenMotor.com

Russell

Well-Known Member
Apr 19, 2009
1,276
155
63
MA
I was looking for a simple jackshaft setup and this is it.
 
Last edited:

Russell

Well-Known Member
Apr 19, 2009
1,276
155
63
MA
The angles that the meet the bottom tube have the same shape as the tube. They are welded to the tube (zero movement). Guess that I could have used shaped u-bolts, but a few welds were easy.
The mtr-mnt has slots for chain strech adj.
 
Last edited:

NEAT TIMES

New Member
May 28, 2008
1,964
1
0
PENSACOLA, FL
Russell

Super Nice. How Do You Like The Gear`s/multi Speed`s, After Having The One Speed Ratio?? Your Spoiled Now, Hard To Go Back!!

I Tried To Find Pipe And Bearings That Fit And Would Not Need Lath Work! Had No Luck. If You Don`t Mind, How Did You "Git`r Done" ?? Are You Using 5/8" Shaft? Do You Have A Bearing Number And The Tube Spec`s?

Thanks For Sharing. .Ron .cvlt1
 

Russell

Well-Known Member
Apr 19, 2009
1,276
155
63
MA
Russell

Super Nice. How Do You Like The Gear`s/multi Speed`s, After Having The One Speed Ratio?? Your Spoiled Now, Hard To Go Back!!

I Tried To Find Pipe And Bearings That Fit And Would Not Need Lath Work! Had No Luck. If You Don`t Mind, How Did You "Git`r Done" ?? Are You Using 5/8" Shaft? Do You Have A Bearing Number And The Tube Spec`s?

Thanks For Sharing. .Ron .cvlt1
Neat times,
The five speed works great. The cluster is 14-28 tooth. In first gear 28T you are ready for Mt. Everest. In 5th gear your moving much faster than you should be. Really, all I use are the three mid 3 gears.

I have two other bikes (both 1 speeds). They have good motors and really seem to meet 90% of my riding needs. The 50cc needs a little help on hills but the c-clutch 66cc handles about anything.

I use a 3/4 shaft as that is what came with the $40 shaft/sprockets/bearings pkg. The bearings are 1 3/8 OD. The bearing tube is 1 1/4 black gas pipe. I had to try a few pieces of black pipe berore I got one that fit tight(guess the ID varies a few thousanths).

It really is a simple setup and only the pedaling load goes thru the freewheel.
 
Last edited:
Jul 22, 2008
656
0
16
Northglenn,Colorado
I'm trying to figure this out. You have the freewheel on the jackshaft? I don't see it on the crank. Can you still pedal backwards while moving?

(edit) Oh I see it now. The freewheel sprocket on the crank side does the freewheeling.
Now how did the smaller drive sprocket get in there?
And you got roller bearings spinning the shaft?
(edit) Just saw first pic.

This is real slick! Makes me wish I had a welder.
And it's GREAT that you don't need a freewheel crank.
BRAVO!
 
Last edited:

Russell

Well-Known Member
Apr 19, 2009
1,276
155
63
MA
I'm trying to figure this out. You have the freewheel on the jackshaft? I don't see it on the crank. Can you still pedal backwards while moving?

(edit) Oh I see it now. The freewheel sprocket on the crank side does the freewheeling.
Now how did the smaller drive sprocket get in there?
And you got roller bearings spinning the shaft?
(edit) Just saw first pic.

This is real slick! Makes me wish I had a welder.
And it's GREAT that you don't need a freewheel crank.
BRAVO!
Yes the freewheel on the motor side is welded and only used as a regular sprocket.
Pedal backwards, Hmm never occured to me to do that but yes I could.
I welded the motor side freewheel so it could be pedal started. The original concept for the motor side freewheel was to reduce drag with the motor not pulling.
 

Russell

Well-Known Member
Apr 19, 2009
1,276
155
63
MA
NT,
The inside sprocket is 10t. If you work the ratios, I think you'll like the results.

I am making two of these units now that use different sprockets but end up with a similar output.

Russell/james65
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
Good work on the J shaft(^) I like the way you did the drive pulleys on the right side. I am a fan of that approach.
 

Russell

Well-Known Member
Apr 19, 2009
1,276
155
63
MA
Jackshaft kit was
bmikarts.com
Part # 400950
#41 10 & 14Tooth sprockets
A 18 T would be better than a 14tooth but they do not offer it with the $29 kit.
 
Last edited:

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
Nice job Russel. Would this setup work equally well with a cruiser build or is it most appropriate for a chopper? I'm guessing that having enough room is an issue. Our options keep expanding.
SB
 

hepcat_13

New Member
May 19, 2010
26
0
0
New Orleans
I plan on putting it on a electra Ratrod. I stared at my bike long enough to work it out in my head. I think if you have access to a welder and fab skills you could use almost any bike with this set up.
 

panheadman

New Member
Feb 20, 2010
3
0
0
Billings, MT
Thanks Ron--haven't had any problems with the carb at all, although that was one of my worries when I built it. I've been thinking of putting on one of those racing carbs and if I do will build a straighter intake then. I have probably got between 500 and a thousand miles on it with only minor problems--getting the derailluer adjusted right, etc.usflg
 

WayneC

New Member
Aug 2, 2009
173
0
0
Clearwater, FL
So where does one get a 10T sprocket for the jack shaft to drive the small bike chain?
Source?


Never mind, I see Staton sells them in various tooth counts.
 
Last edited:

igarza

New Member
Sep 16, 2010
1
0
0
Illinois
Russel:
That is beautious. I was sitting at the kitchen table sketching up a jack shaft and trying to figure out how to make it, and here you have already done it.

Great job.
Ivo
 

DudeZXT

New Member
Jun 20, 2010
115
0
0
Lexington, KY
This is awesome! Would you mind sharing a part number list for getting all of these parts from McMaster? My job gets parts from them all the time...
 

Russell

Well-Known Member
Apr 19, 2009
1,276
155
63
MA
Although I had no problems with the bearings that came with the BMI kit, if I were to do it again I would use the sealed bearings and a 5/8" shaft from sickbikeparts.com(very reasonable).