Combined mtr-mount & jack shaft

[Russell]

I was looking for a simple jackshaft setup and this is it.

 

[Patr1ck]

Thats pretty slick. Does the engine try to spin around the frame tube at all?

Pat

 

[Russell]

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.

 

[Patr1ck]

Thats pretty cool. Nice work.

Pat

 

[NEAT TIMES]

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 .

 

[Russell]

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 .

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.

 

[Large Filipino]

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!

 

[Russell]

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]

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]

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]

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.

 

[hepcat_13]

I'm digging the way you did this. I'm working out the parts now. I'll have mine built within the next 2 weeks.

 

[silverbear]

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]

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]

Nice work Russell--I built a similar one

 

[panheadman]

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.

 

[WayneC]

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.

 

[igarza]

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]

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]

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).