Seeking advice on rear wheel sprocket options

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Sidewinder Jerry

Sidewinder Jerry

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woody6 said:
That's a neat idea I need to consider. I was hoping to keep the coaster brake, and ideally I didn't want any handlebar levers, but had to relent and add one for the front hub brake. The originals didn't have a front brake, but no front brake seems perhaps too realistic.

I guess my preferred option would some way to solidly add a second sprocket to a coaster brake hub. I have one of the aluminum, 2 piece hub adapters that clamps on to the hub, but it can slip.
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It's always best to place safety over looks and/or originality, if you plan to be on the public roadways. I once had a 64' step-side Chevy pickup truck. Originality is cool but that gas tank came out from behind the seat and went under the truck. Seat belts also were put in as well.
 
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woody6

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I thought I would post an update, as I really appreciate all the input and suggestions everyone provided.

I have added Pat's hub adapter, and I reluctantly removed the 3D clutch (which I liked for many reasons including pedal starting on the road or on the stand). I also added a beefy front motor mount, a stainless muffler, a brass brake lever and white tires for a vintage look, and remade my rear fender mounts so that they are much sturdier. I am testing with an inexpensive centrifugal clutch, and today got the mikuni-clone carburetor tuned and adjusted for better off-idle throttle response. I am amazed at how torquey the predator engine is. Earlier I had some minor slipage of the hub adapter (which Pat makes clear is NOT recommended for a 212cc engine), but further tightening of the bolts seems to have alleviated that. I didn't see a torque spec with the adapter, so I was probably overcautious when tightening it the first time.

indian_trib.jpg


I have zero plans to hot-rod the engine, as I plan to use this thing like a moped around the neighborhood, probably 25mph max. But if I do have hub adapter issues, I have a punt position. I have purchased a moped hub and would like to build up another wheel using it, and 10g spokes. I'm trying to find a source for a beefy steel 26x1.75 steel rim that has a drop center like an automotive wheel (or a raised spoke area, if you prefer). I have a pic below, does anyone know where to source such a wheel?

steel_rim_and_moped_hub.jpg


The next step will probably be to blow it all apart. I have a friend who was a crack auto-body guy in his younger days, and he's offered to help me do the whole thing up in Indian Red. I have some gold Indian tank logos, and may do some gold pinstriping. I'll keep everyone posted.
 
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woody6

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Curt, Many thanks, that may be the closest that I have seen. It is nice that they show a cross-section of the wheel at that link. The wheels I have are a bit more square-shouldered and the sides are flatter, but that may be as close as I get without knowing the source of the originals.

Question: Is the acceptable to drill the spoke holes for a larger nipple for the 10g moped spokes? I measured the 12g and 10g nipples and the difference seems to be minimal. I want to think enlarging the spoke hole such a small amount would be a non-issue.
 
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Wevil Kenevil

Wevil Kenevil

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woody6 said:
That's a neat idea I need to consider. I was hoping to keep the coaster brake, and ideally I didn't want any handlebar levers, but had to relent and add one for the front hub brake. The originals didn't have a front brake, but no front brake seems perhaps too realistic.

I guess my preferred option would some way to solidly add a second sprocket to a coaster brake hub. I have one of the aluminum, 2 piece hub adapters that clamps on to the hub, but it can slip.
Click to expand...
Be careful brother, a standard coaster brake WILL BUCK YOU OFF YOUR BIKE QUICKER than you can imagine. This is a very real danger.

And lose the two piece brake adapter, it will fold on you just as sure as spit. "Bikebury" carries a single piece billet brake adapter that is much safer but still sketchy as an etch a Sketch. I would opt for forks that have the bracket already on them.


But who needs brakes life is overrated anyways... Jkjk.
 
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woody6

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Wevil Kenevil said:
Be careful brother, a standard coaster brake WILL BUCK YOU OFF YOUR BIKE QUICKER than you can imagine. This is a very real danger.

And lose the two piece brake adapter, it will fold on you just as sure as spit. "Bikebury" carries a single piece billet brake adapter that is much safer but still sketchy as an etch a Sketch. I would opt for forks that have the bracket already on them.


But who needs brakes life is overrated anyways... Jkjk.
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I appreciate any and all advice, so bear with me here. How will a coaster brake on the back of a bike buck me off? I'd be more worried that it would let me run into something! Then again, every coaster brake bike I rode as a kid would let me lock up and skid the rear wheel.

As for the two piece brake adapter, are you referring to the larger springer lever on the front fork, that I had CNC cut and added the hardened bolt to locate the front drum? It is about 1/5 of an inch thick, I don't think it is going to fold without the aid of a torch and big hammer.

Don't get me wrong. I do want this thing to be reasonably safe, and I've gained a ton of appreciation for what the folks on this forum are building.
 
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Wevil Kenevil

Wevil Kenevil

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It's something to do with the forward momentum and trying to engage the coaster break it catches and throws the pedal forward quicker than you can pull your foot off the pedal. Seriously...

The coaster brake operates on a worm gear type thread and with the forward torsion of the motor the way that the coaster brake engages it climbs the worm gear causing the crank to abruptly lurch upward causing the rider to lose control.


It almost caused me to wreck I hope you never experience this. Has anybody else experienced this either? I've seen it do it on two different bikes.
 
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Wevil Kenevil

Wevil Kenevil

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woody6 said:
I appreciate any and all advice, so bear with me here. How will a coaster brake on the back of a bike buck me off? I'd be more worried that it would let me run into something! Then again, every coaster brake bike I rode as a kid would let me lock up and skid the rear wheel.

As for the two piece brake adapter, are you referring to the larger springer lever on the front fork, that I had CNC cut and added the hardened bolt to locate the front drum? It is about 1/5 of an inch thick, I don't think it is going to fold without the aid of a torch and big hammer.

Don't get me wrong. I do want this thing to be reasonably safe, and I've gained a ton of appreciation for what the folks on this forum are building.
Click to expand...
And anything you need to know ask the OG's on this forum they are happy to help and they are as wise as they are kind.

I haven't had a problem yet that they could not help me with or steer me in the right direction...especially sidewinder Jerry with his ability to calculate speed by rim size and back sprocket... I suck at math so this kind of amazes me.

(And sorry I thought you were talking about the cheap two-piece wrap around brake adapter. )
 
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Venice Motor Bikes

Venice Motor Bikes

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Wevil Kenevil said:
Norm is a definitive source of knowledge, I trust him but not so much the brake.
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What you're saying about the coaster brake kicking the pedals forward is very true, (if you don't add the extra grease).
Those hubs come from the factories with the absolute minimum of grease inside them.

I prefer coaster brakes over rear discs or drums... & I really like how they make the rear of the bike look simple & less cluttered.

I've used them on several of my 212cc builds & never had a problem.


Here's a couple of my favorite 212 bikes...
Venice Ruff Cycles Chopper Build | Motorized Bicycle Engine Kit Forum (motorbicycling.com)
Another 212cc Predator bike from VeniceMotorBikes | Motorized Bicycle Engine Kit Forum (motorbicycling.com)
 
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Wevil Kenevil

Wevil Kenevil

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woody6

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Wevil Kenevil said:

At the 13:36 time marker.

I realize that it's just a putt bike that you have but still it is something to take into consideration because it happens quicker than you can imagine.
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Very interesting, and no doubt an unpleasant surprise when it happens. At the very least I need to apply the extra grease to the coaster brake, but also this might be just one more reason to work on getting the moped hub in the rear wheel (it uses a more conventional drum).

I appreciate everyone's input, I'm having a blast tinkering, testing, and learning.
 
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