anyone have a 3 speed 3 piece crank solution

[xlander]

So I've put my kit in a mountain bike because cruisers don't feel like a safe ride. Trouble is the junk crank sets that come with most kids are tool pressed brass... And only one speed. Which means it's worthless if you ever need to help your helper motor.

Did anyone have a wide 3 piece set of arms. Maybe someone has the connections to get them made.

It should be relatively universal. Every multi speed system I've seen for nearly 20 years uses a five bolt pattern to hold the chain rings. So basically w just need a machinist to copy an existing set of arms. Then modify them to a wider stance. Via atm bend or extended atm base cast.

The best part is. If someone can reproduce this the kit would only need the arms. Because any other parts would already be in the bike.

The amount to extend would be about 4cm.

Note before you suggest pedal extensions. The damage crank asthma by pulling out the pedal threads. Also they are way over priced. Who wants to spend 40$ on parts that break your bike.



Thanks in advance to any solutions. Maybe someone knows how to suggest it to manic mechanic or Dan Grube?

 

[cannonball2]

Are you looking for something like this? They have various sizes. http://www.sickbikeparts.com/catalog/product_info.php?cPath=23&products_id=114

 

[frank66]

3 spd hub likely.
singlespeed cranks from ebay maybe.

 

[frank66]

scratch the 3 speed hub if you have a slim budget. maybe grubee cranks like the wide ones and add a centrificall clutch and pull starter for a ggg setup. give-gas-andgo.

 

[xlander]

Reply to first reply: No that wider crank bottom bracket won't work thanks though. The gears on the pitfalls would be way too far out. The chain would jump off with every attempt to pedal.

I don't want a single speed crank because the ones made for this application are need very poory. That single speed chain ring is roll press. Also I forgot to mention. I fight random hills, but am usually in the flats. So I don't want to change the drive gear. However to keep the motor out of bog. I pedal my butt off with the largest chain ring. Which also shows the uselessness of the wider single speed that comes with the kit. Pedaling wouldn't help with those because they are two low geared for pedaling to help.

So in short thanks but the low quality and lack of usefulness of the kit cranks is no bueno.

Third response: sounds great I tried to figure out how to make that but got no response on the forum from the only set up like that I have seen.

O wait no that went change my pedal problem. My pedals would still be slapping the bottom of the transmission cover.

 

[KCvale]

So in short thanks but the low quality and lack of usefulness of the kit cranks is no bueno.

O wait no that went change my pedal problem.
My pedals would still be slapping the bottom of the transmission cover.

Just re-orient your (I assume) 7G 4-stroke transfer case?

It's just a thick but soft aluminum base plate.
You can drill new mount holes in it to raise the back of transfer case up.

The top of crank arms can clear it that way on the left.

The right side is another matter but you should have enough there so long as the crank arm is below the pull starter.

Personally I find front sprocket gearing on an MB to be just plain silly, you have back sprocket gearing and an engine.

On a 2 stroke build, which have a clutch lever of course, I remove the front derailleur and it's control and just have the rider manually move the chain to a different front sprocket to fit their pedal needs, but that's 2-stroke.

On a 4-stroke direct drive there are indeed 2 real 'pedal help' ranges.
Nice and easy from a dead stop, but still be able to assist at high speeds....

Seems you should be able to do that with your rear cartridge sprocket sizes.

 

[frank66]

just buy a faster engine or cylinder. or a scooter. it sounds like the engine makes little power.

 

[xlander]

just buy a faster engine or cylinder. or a scooter. it sounds like the engine makes little power.

Yes unfortunately this is covered by a legal issue in my area I am at and one CC over max allowed.

Arizona house bill
HB2796
History

Current statute does not contain a definition for a motorized electric or gas powered bicycle or tricycle. Current statute defines a “moped” as a bicycle that is equipped with a helper motor if the vehicle has a maximum piston displacement of fifty cubic centimeters or less, a brake horsepower of one and one-half or less and a maximum speed of twenty-five miles per hour or less on a flat surface with less than a one per cent grade.



Federal regulations state the following:

1. For purposes of motor vehicle safety standards issued and enforced in the United States Code, a low-speed electric bicycle (as defined in section 38(b) of the Consumer Product Safety Act) shall not be considered a motor vehicle.



2. The term “low-speed electric bicycle” means a two- or three-wheeled vehicle with fully operable pedals and an electric motor of less than 750 watts (1 h.p.), whose maximum speed on a paved level surface, when powered solely by such a motor while ridden by an operator who weighs 170 pounds, is less than 20 mph.


Provisions

· Stipulates that a certificate of title or registration is not required for a motorized electric or gas powered bicycle or tricycle.

· Exempts a motorized electric or gas powered bicycle or tricycle from license tax.

· Exempts a motorized or gas powered bicycle or tricycle from laws relating to required equipment on motorcycles and motor-driven cycles.

· Exempts motorized electric or gas powered bicycles or tricycles from vehicle emissions inspections.

· Permits the operation of motorized electric or gas powered bicycles or tricycles without a driver license.

· Allows motorized electric or gas powered bicycles or tricycles to use the right-of-way designated for the exclusive use of bicycles.

· Exempts motorized electric or gas powered bicycles or tricycles from vehicle insurance and financial requirements.

· Defines “motorized electric or gas powered bicycle or tricycle” as a bicycle or tricycle that is equipped with a helper motor that has a maximum piston displacement of forty-eight cubic centimeters or less, that may also be self-propelled and that is operated at speeds of less than twenty miles per hour. (This means not over 19MPH. It also menas that we are all operating illegally, if taken to court by an educated police officer.) What isn't stated here. (20-25 Mph is classified as a moped, Mopeds aren't allowed to use bike lanes or allowed in speed zones above 35 MPH. This also requires registration and insurance I believe, as well as paying to have your bike vin'd by a motorcycle building shop, but not a motorcycle license. 25 MPH and up is classified as a motorcycle. This means getting Vin'd, licensed, registration and insurance. At the same time if it cannot achieve and maintain a speed above 35 I am pretty sure you are still moped restricted as to where you can ride.
All of these laws are adjustable by cities.
so I can't go bigger or faster unless I want to lose my real license,and have tons of tickets and fines

It has enough power I am just trying not to put it all on a little motor when I am going uphill. I am 230lbs. Sure I am tall and don't look heavy but, that plus my gear weight, bike, thick tires and tubes, and motor kit, makes an issue. I'm trying to make it last not beat it into submission.

So says the poor kid that the VA has forced to stay unemployed for just short of a full year. Yet doesn't want to pay a livable pension.


Thanks for your input though.

 

[xlander]

Post in work to try and show images instead of links. No luck I can't post images from google drive. Sorry about that. I tried multimple methods to get this site to show the image instead of the links.
Sorry due to limitations of the site playing well with google drive, and likely googles fault. You will have to open links because they wont display when I try to insert them as an image.

Yes this is a 7g build using the kit sold by gasbike. net

Alright so back to what I was asking. Does anyone here have the connections to make a product. It would be a first of its kind. So likely a decent profit turn.

Most of my next post replies and thoughts are detailed in words in the pictures themselves.

https://drive.google.com/file/d/0B79sg3Iez1J5RVhDclFnQXUxams/view?usp=sharing

Now this one you have to keep in mind I am putting around 200-600 miles a week on this bike the weeks I am using it. ...Yes it has held up so far no wear on the bushings that everyone claims are so bad. I oil them once a week or so.

https://drive.google.com/file/d/0B79sg3Iez1J5WndQc3Y5cHZRb1k/view?usp=sharing

https://drive.google.com/file/d/0B79sg3Iez1J5UFBUR0RGLUF6MjQ/view?usp=sharing
PS: KC since you are working on a more stable bolt on base/platform. If you are still getting down drifting because of vibration. You may want to look into the solution I have in this pick.[/COLOR]

This pick shows why I can't reposition the transmission into the upward position.
https://drive.google.com/file/d/0B79sg3Iez1J5Q1FxRThHTV9rY0E/view?usp=sharing

 

[xlander]

These next three images layout some thoughts on my problem and show the damage currently being caused.

Keep in mind the closer you can get your motors drive chain to match your pedals dive chain. The better off you will be. The further up the motors drive chain is from the axis of the pedal chain the more torque you lose to the wheel, as well as MORE TORQUE PULLING YOUR MOTOR MOUNTS DOWN. (Not a shouting sentence and emphasis.)

Again images wont post as images. Not sure why I guess something to do with google.
1 of 3
https://drive.google.com/file/d/0B79sg3Iez1J5cUdtYXRuZW8xVzA/view?usp=sharing

2 of 3
https://drive.google.com/file/d/0B79sg3Iez1J5cS1iVnYxTTRzbTQ/view?usp=sharing

3 of 3
https://drive.google.com/file/d/0B79sg3Iez1J5VWViYnBMLVFVWmc/view?usp=sharing


If anyone can recommend an image hoster that doesn't delete files over time, and is also free. Let me know. Maybe google just isn't any good as an image hoster.

End of replies with links for pictures.

 

[xlander]

I would say for a set of QUALITY Cranks arms that work with a typical 3 speed crank set. they would also need to have the pedal thread set at the adult bike size of 9/16 pedal thread. After all its illegal for kids under 16 to ride these. So full sized feet are need the other pedal thread would only work with kid sized pedals. (In other words I use the bottom bracket that is already in place on my bike and attach the arms only. Note that in the picture with my chain-ring side arm. The chain rings are bolted on. In other words the builder/designer would only have to make a wider arm using that bolt pattern. They wouldn't even have to include chain rings because that is already on your bike.

I would be willing to pay 50-100$. Anyone that wants to build a multispeed motorized bike decently would likely pay the same.

I realize that for a single unit production that sounds a bit low. This is why I mention knowing people that make custom parts. Like manic mechanic. They could make enough to make that cost reasonable over multiple customers. They could also make some single speed cranks that aren't built half assed like everything on the market current. (That I have found so far.)

I would have written manic mechanic

 

[xlander]

If your having trouble visualizing. Here is a basic design layout. Of course someone with better talent in this department would be able to improve.

https://drive.google.com/file/d/0B79sg3Iez1J5SGFmWXB4UnlmZkU/view?usp=sharing

In the picture I drew I forget to mention that the placement of the chain ring arms must flush in like the original arms. Only the arm gets extended out beyond what is normal... like the arms I have pictured in previous posts. Otherwise the misalignment of the chain from front to rear gears would pull the chain off the front.

If someone is able to reproduce the design it would be the last thing I need to do to my bike to "finish" the build.

If I ever get a good crank arm set up. I would pit my bike against any for long distance rides.

 

[KCvale]

If someone is able to reproduce the design it would be the last thing I need to do to my bike to "finish" the build.

In order to separate the front chain rings from the right pedal crank you need a way to independently attach the sprockets to the crank shaft.

SickBikeParts does for their 4-stroke shift with a wide sealed BB with a notch to attach a sprocket set.
Theirs is a freewheel which you don't need but the principle is the same.

A simple sleeve with sprocket mount holes with a keyway and set screw to keep in place on the custom wide shaft would work.

You do however severally underestimate what the machining a part costs if you don't have a diagram and the milling machine code ready to run are.

I do.
It's not the cost of the material or time it takes to mill a shaft, it's the machines program to do it that is the initial big cost.

If you are an engineer with CAD and an output in a machine code it's cheap, it's when you want someone else to do it that it gets expensive.

If I ever get a good crank arm set up, I would pit my bike against any for long distance rides

I will assume you mean any direct drive 49cc 4-stroke, you haven't rode a 3-speed 49 with the good mods yet ;-}

And as for AZ law...
48cc, but if you take the posted specs in Watts and do some math it's like 48.8cc or something but the point is no court in AZ has time to dink with how big your engine is BS.

 

[Scol]

I have the same problem. I am just after fitting my engine kit and have enought
room to leave the gears ( 3 rings ) at the peddles.

The peddle arms are aluminum and the peddles are steel so can't weld. I screwed 2 1/2 inches of wood onto the peddles just to see how it would feel and it works. So this weekend I'm going to change the wood for steel just for the moment.

I went to a machine shop and he can make up from a solid bar, extentions for the peddles to the arms. I'm not sure if there will be too much pressure and they will end up bending/braking but if I want to keep the gears at the front of the bike I think it's my only option.