Anyone Running Power THRU the Bottom Bracket?

[CrazyDan]

Came across these photos while looking for parts. It would seem there's at least one other bike running a Y setup.

Unfortunately, I have no idea who built this; it was in a "customer photos" section on this page.
View attachment 97768
View attachment 97769

It does look a fair bit cleaner than the SBP setup, although not as easily adaptable.

That suicide shifter to the rear internally geared hub is the icing on the cake.
I'm not too sure how deraileurs will work changing the chain angle, so you might have to keep it the same for a derailleur to work on the right side, or just go with an internally geared hub. Another thing I've seen is using an IGH as the jackshaft, then you can use a single speed or geared rear hub for even more gears, 2 mph max to 50mph .
I have 3 working nexus 3 speed hubs now...

 

[CrazyDan]

Or build our own left hand lower drive...

The Left side of the pedal crank set...

Then too a reversed internal left hand rear gear set...
Of course we would need to rely on our machine shop person to build this for us... Ha
View attachment 97771


Part of the trick is too use a 140,,, 160,,, or 200mm fat tire bike frame...

Use a narrower hub so we can add a left hand side engine drive sproket,,, or add a thinner right hand side cassette too gain more room for the engine drive side...

No Jack-shaft kit needed,,, the engine is easy to swap out since there is no Jack-shaft brakets in the way """if"" we need too swap out engines,,, and the pedal bike chain and gears remain untouched...

We will put a wider crank set stem on,,, a large floating bearing so the 2 sprokets turn by engine power on Left side...
1 sproket the driven,,, the other will be the drive that will feed power to rear hub...

Yes,,, thinking out side the box,,, at least there wont be no Jack-shaft kit ...
And we get to run the heavy duty drive chain

Still designing Don

When the rear tire is going around,,, both chains to sprokets will be spinning,,, let clutch out and Zoom Zoom...

We will find out if our machinest can add a nutral in the rear internal gear hub...
That way we can pedal the bike with no engine drive chain drag...

The drawing is a 2+ 2 gear set for the engine power side...

We've been working on this for years, do a search on left side shifting on this and the other forum. If you can figure out how to make it happen and into production, I'm sure you might get a few extra boyfriends .
Edit: The best we figured was to mirror the right side components but with thicker plates on the hangers or derailleurs. Someone might make a left side cassette that mounts to the 6 bolt disc mount. The derailleur would be a mirror image to a normal one. Enjoy .
Edit 2: another thing you can do is have 2 output sprockets and 2 on the rear wheel, one set for offroad and the other for streets. You will need to match tooth counts between the pairs. Let's say you have a 13 and 9t output cluster, now you can have a 40 and 44t wheel cluster. Just pull over and swap the chain from one run to the other, no links needed or removed. That would give that chain run a 3.08:1 reduction on the 13:40 and 4.89:1 with the 9:44. That on top of a previous reduction, whether internal like the 2 stroke kit motors, or with 4 strokes the belt reduction kits (unless you count staton's crazy 16.7:1 geared reduction drive that reverses rotation (turn the engine facing the carb forward), then you can pretend the motor was meant for rhd.)

 

[FurryOnTheInside]

I'm shocked at my lack of progress since last year although I've an excuse of sorts.
My back suddenly went tonight too. Its agony.

You'll have to read the thread on the development of the Shift Kit to see the "previous art" .
All the work that was done on the alternatives like a heavy duty LHS derailleur and other ideas. No point in trying to reinvent or more importantly it is more alternatives you can see and read exactly what happened and how and why it was decided to do it differently.
For example I bought especially and then tested a nice Shimano Saint short cage derailleur to destruction on the LHS, putting the bump start stress through it's locked ratcheting system, and snapping off the derailler's cage in the process. I did it for myself, then posted my sucessful test of its inadequate strength so nobody else needs to repeat the same exact destructive test.. or no one who bothers to read my posts anyway. It needed to be done to find out, but only once. The idea is sound but parts need to be at least 2x larger and stiffer and stronger. If these parts existed then they may be a way to a LHS bump start (fixed) multi-ratio drive system that can be changed almost on-the-fly but has limited range.


The universality of the Shift Kit by SBP is as close as we will get to a totally universal kit that does shift and has a good range of ratios. Its drawback is the Z arrangement for the chains and 2down-1up ratios that waste some power. Im not entirely sure if it is possible to get the ratios between pedal and engine to allow human helping/exercise. Most say that if you have decent compression, then to start the engine you need a small enough ratio that means no you cannot pedal along with it. So in winter you will be cold or you'll just ghost pedal. To me pedalling is a natural response to the forward movement its just natural to move my legs even if I'm not really putting any effort into it. I don't have to worry about getting cold now im too late in life, lol.


The Y arrangement is going to require a little more work to fit and has less universality for the common bicycle frames available which are smaller and shorter for quick handling and low weight. Longer cruiser frames will be easier or less limited on sprocket maximum sizes.
Also the issue about the derailleur angle now its driven from a JS sprocket, higher up the mid frame: I believe that the B screw adjustment will fix most of the issue.
A wide (or mountain bike 2 speed) idler pulley might be necessary on some frames (with V or trumpet stay areangement when viewed from above as opposed to cruisers with their U shape) to lift the chain over the middle of the chain stay while not affecting lateral freedom of movement.
A skid instead of a pulley might even be possible if its seen as a consumable for racing??

 

[5-7HEAVEN]

FOTI, my back's acting up too. I strained it 30 years as a telephone lineman, then reinjured it 10 years later on the same job.
Due to the pandemic, I'm chained to my work desk. It's aggravating my old injuries.

Ben-Gay is my new friend!
It seems to work, and I love its smell, lol.

 

[5-7HEAVEN]

Eureka!!

I problem-solve in my sleep, seaching for solutions.

I'm gonna try this method of running power thru the bottom bracket.

It doesn't matter if it delays my build.

For me, it's all about planning and building things my way, then riding.

Thank you, stimulus checks!


As the bank robber told Police Inspector Callahan in "Dirty Harry".....

"I gots to know!"

 

[5-7HEAVEN]

Since there's no connection between the pedal arms, there's no synchronizing them. Once bottoming out, pedals have to be lifted into position with the top of each foot.

That's not good.
The project was almost scrapped.

The idea of leaving them on as props, to ALMOST look like an mb with pedals....
that crossed my mind.

I thought of installing foot straps on the foot pedals, known commercially as Power Grips.

Then!!!


How about installing stiff return springs on each pedal arm?!
And pedal stops, of course.


Tabs could be welded on each pedal arm, below where it attaches to the BB shaft,
The springs attach to welded tabs near the front of the motor mount.
The return springs/pedals are similar to brake and clutch pedals on pre-1955 cars.

Floor board pedals, with pedal stops.

Both bike pedals will now pivot independently at the bottom bracket. They will be limited to a 45-degree forward operating range, much like the old water boats at the amusement parks.

Each arm can work independently or together, and create forward motion.

THAT would look odd, pushing both pedals at the same time, lol.

Orrr, this method would allow a one-legged handicapped person to operate a bicycle more efficiently!

Seriously.

If this invention bores me, it's a simple matter to change the pedal arms and relocate the chainring pulley and jackshaft pulley.

Thoughts?

 

[5-7HEAVEN]

Back to planning.....

If pedals were eliminated, the engine would happily send power thru the shaft, from left side to right side of the bike.

However, if pedals were simply bolted onto the BB shaft, they would literally beat our legs to a pulp, once the engine fired up!

One stumbling block of having working pedals is separating the engine's rotation from the pedals' rotations.

In my previous posts, I mentioned having the engine's 83t chainring on the left side of the bike, and the 24t driving chainring on the right side.
It doesn't matter if the cogs are welded or bolted to the BB shaft, with or without freewheels.

Now I have found everything to make this invention work, even the rare freewheel and adaptor with left-hand threads(LHT):

http://www.staton-inc.com/store/index.php?p=product&id=2146

https://www.ebay.com/itm/Bike-Bicyc...848884?hash=item3d70586f34:g:KRcAAOSwUUZbcoh7

These are necessary to prevent the pedal arms from unscrewing the freewheel and falling off the bike.

One side uses LHT equipment; other side needs RHT stuff.

 

[5-7HEAVEN]

I believe everything's planned out.

Now comes the working pedals!

There are 2 reasons for having a BB shaft that's keyed from end to end.
BB cartridges have a 1" groove on the right side, and nowhere else.
One reason is to have a solid connections for pulleys on both sides.... THE KEYWAYS!

So the one piece BB cartridge is replaced with the old-fashioned 3-piece bottom bracket, having a shaft, cups and ball bearings..
An 8" keyed shaft will be the BB shaft.

The second reason for having a fully-grooved shaft is to have solid connections for the freewheel adaptors at each end of the BB shaft.
These are the keys and keyways.

Freewheels allow movement of two separate gears in one direction, like the rear wheel hub and hub sprocket.
Try to picture the BB shaft as the rear wheel hub and the pedal arm as the hub sprocket.

Each freewheel is screwed onto its adaptor.
They are then secured on the outer ends of the BB shaft.

Now comes a bit of fabrication and welding:

A plate of .25" steel is cut into a 3.5" circle. It's then drilled to match the freewheels' 4 or 5 mounting holes.

The plate is bolted onto the freewheel, on the outer edge of the shaft.
The pedal arms are then welded to the center of the plate.

So the end that normally bolts onto the BB shaft is welded onto the steel plate.

The pedals no longer bolt onto the BB shaft.
They freewheel, while the engine spins the BB shaft.

Due to freewheel action, the working pedals can now spin the BB shaft.
This is with or without the engine running.

 

[5-7HEAVEN]

Or build our own left hand lower drive...

The Left side of the pedal crank set...

Then too a reversed internal left hand rear gear set...
Of course we would need to rely on our machine shop person to build this for us... Ha
View attachment 97771


Part of the trick is too use a 140,,, 160,,, or 200mm fat tire bike frame...

Use a narrower hub so we can add a left hand side engine drive sproket,,, or add a thinner right hand side cassette too gain more room for the engine drive side...

No Jack-shaft kit needed,,, the engine is easy to swap out since there is no Jack-shaft brakets in the way """if"" we need too swap out engines,,, and the pedal bike chain and gears remain untouched...

We will put a wider crank set stem on,,, a large floating bearing so the 2 sprokets turn by engine power on Left side...
1 sproket the driven,,, the other will be the drive that will feed power to rear hub...

Yes,,, thinking out side the box,,, at least there wont be no Jack-shaft kit ...
And we get to run the heavy duty drive chain

Still designing Don

When the rear tire is going around,,, both chains to sprokets will be spinning,,, let clutch out and Zoom Zoom...

We will find out if our machinest can add a nutral in the rear internal gear hub...
That way we can pedal the bike with no engine drive chain drag...

The drawing is a 2+ 2 gear set for the engine power side...

Actually, Dan, my previous bike was very similar to what anyone can build for left-side drive.

However, power was on the right side, to utilize the common right-hand threaded(RHT) freewheel.
The engine's power take off(PTO) shaft faced to the right side of the bike. Its counterclockwise movement was changed to clockwise, by using a pocketbike's 5:1 gearbox.
The gearbox's sprocket was then chained to a freewheeling chainring sprocket, then power to the rear hub.

The key to it all was the SBP pedal arm. It's machined to accept a RHT freewheel.
The driven chainring sprocket was screwed onto the SBP pedal arm.

Now came the the magic!

The 24t driving chainring sprocket "floated" around the BB shaft. It was not connected directly to the BB shaft.
The 24t was connected the the freewheel on the SBP pedal arm!

The 72t chainring sprocket was connected to the freewheel on the SBP arm thru 5 long studs.

Then with 5 1" spacers attached, the 24t was connected.

It worked like a charm for almost 10 years, until I de-commissioned the bike.

Sooo, this idea of left-side drive could be brought to reality, with ONE special $20 item and ONE simple machine job.....

Machine the left-side pedal arm to accept the left hand threaded(LHT) freewheel!

That's 1.375 x 24 left-hand thread.

In the end, one could have a 10t clutch with a 36t chainring, then a 24t driver with a 48t rear sprocket.

Final drive would be 7.2:1, if desired.

That's all that's needed to make this work!

 

[5-7HEAVEN]

The reason I want to do it is there is less hp lost getting rid of 2 sprockets, a shaft and a chain from the engine to the rear wheel, but retaining the pedals. I accelerate much faster and can maintain a higher speed up a hill with my pedals, Don't want to lose them. Even with a 212 on a shift kit you will notice a slight power increase when you pedal, similar to a small nitrous shot. Also, as I said, pedals are a must for the socal races.

Two reasons I'm blazing this trail:

Reason #1: I'm consolidating ALL! gears and pulleys to the LEFT & FRONT of this bicycle.
NO MOVING PARTS!! past the clutch.

Reason #2: no motorized belts or sprockets on the right side of the bike.

A regular chain guard could be installed.