Seeking advice on rear wheel sprocket options

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woody6

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Oct 18, 2023
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Novice and long time lurker looking for advice.

Having restored a couple of cars, I was looking for a smaller project. I like the board track racers, but had also been impressed with a dark red 1913 Indian street bike that I had seen at the Barber Museum in Birmingham, AL. I thought it would be fun to build something reminiscent of that style, as a 'tribute', since I would take some liberties here and there.

I already had a engine sitting in the basement waiting for a project, when someone's abandoned board track racer showed up on ebay and garnered no bids. I made an offer and ended up the new owner.

The plan was to use the frame and square-sided tank, but emulate some of the Indian details. The engine would be a that predator hemi I had sitting in the basement. The bike would be burgundy with gold Indian decals, predator engine, monarch fork, white tires, with a freewheeling gear reduction on the pedal crank shaft. I also added a 3D clutch engaged by a lever to the left of the tank, and a few 'period' details will help with the vintage look. It won't fool anyone, but that wasn't the point.

It is built, but not yet painted, and I'm working out the drive details. As people here predicted, the predator has plenty of torque to break spokes, and that is what I did.

So what do you all recommend for a stout mating of a rear sprocket to a coaster brake hub? I want something sturdy, but this bike is solely for putting around the neighborhood.

--Woody
 

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woody6

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Oct 18, 2023
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Put the sprocket on a disc brake hub and run a rim brake to the rear.
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.
 

woody6

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Oct 18, 2023
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A Sportsman Flyer hub adapter will grab the hub a lot better than a standard one.
It's a 3-piece design that clamps more evenly around the hub body, & it's also wider where it meets the hub surface... I've used them on several 212cc bikes without any problems.
That's great, it sounds like the perfect/proven solution. Thanks, I'll see if I can get one on it's way.
 

curtisfox

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Dec 29, 2008
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A Sportsman Flyer hub adapter will grab the hub a lot better than a standard one.
It's a 3-piece design that clamps more evenly around the hub body, & it's also wider where it meets the hub surface... I've used them on several 212cc bikes without any problems.
I second this, one of the best. That bike is pro built by one of the builders on the forum, sure looks familiar. Another thing is look up fender mounting on the forum, and make sure you do some heavy remounting, could save you from serious injury.............Curt
 

woody6

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I second this, one of the best. That bike is pro built by one of the builders on the forum, sure looks familiar. Another thing is look up fender mounting on the forum, and make sure you do some heavy remounting, could save you from serious injury.............Curt
Much appreciated, I will search and revisit the fender mounting. I have been trying to make mounts that look like the vintage bike, but I had not considered them as potentially dangerous.

I asked the seller the source of the bike, but did not get an answer. So I would be glad to know where it came from. The frame looks well made, the tank is stainless, and the wheels are heavy duty with 12g spokes and the front drum brake. The tank has a faint lettering that says L M E Cycle. The frame came with an engine mount on it that was the several degrees off of the 15 degrees needed for vertical mounting, and also crooked side-to-side (which is probably why someone bailed on it). I've redone the engine mount, added the fork, fenders, hairpin seat, and created a left-side lever that engages the clutch. It's no where close to what real fabricators here on the forum are building, but I'm having fun and think it will look decently 'retro' once it has the red paint and decals. Here is my inspiration:

indian_guide.jpg
 

curtisfox

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I think it mainly where it bolts to the frame and fork that is most important, You are doing good it sounds like. Post a bunch of pictures as you go, old saying they are worth 1,00 words. just remember It's your bike so make sure you build it the way you want. Looking good so far...............Curt
 

woody6

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Oct 18, 2023
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I think it mainly where it bolts to the frame and fork that is most important, You are doing good it sounds like. Post a bunch of pictures as you go, old saying they are worth 1,00 words. just remember It's your bike so make sure you build it the way you want. Looking good so far...............Curt
Thanks! I agree on the photos, and I have gotten a ton of information, ideas, and wisdom from the forum. I'll post some pics of bits of the build that might help the next amateur builder like myself.
 

woody6

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I mentioned earlier that I started with someone else's abandoned project found on ebay. One of the things that appealed to me about this bike was that it already had some stout looking wheels, spokes, and this front drum brake. Also, while it isn't anything like the Indian's leaf spring, I knew I wanted a monarch fork for a vintage look.

Rather than having a brake lever to attach to the frame, this particular drum brake had a u-shaped slot to prevent the center hub from rotating. It seemed ideal to add a pin to the monarch's lever. I drew up a replica of the monarch wheel mount with an added bump to locate a pin, and ordered it cut with a few other metal parts. An allen head bolt provided the pin, and the wheel can be removed and installed like a normal bike, with only the usual axle nuts.
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sportscarpat

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Never liked the Monark fork action under braking. Take a look at the Sunlite Springer Deluxe fork design. On the Sunlite the front wheel attaches to the front fork leg, not a swing arm, and when using a drum hub you anchor the brake backing plate to the front fork blade as well. A far better design and worth the $200 investment. Hate to say it but Monark forks are just dangerous on a motorized bike.
 

woody6

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Oct 18, 2023
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Never liked the Monark fork action under braking. Take a look at the Sunlite Springer Deluxe fork design. On the Sunlite the front wheel attaches to the front fork leg, not a swing arm, and when using a drum hub you anchor the brake backing plate to the front fork blade as well. A far better design and worth the $200 investment. Hate to say it but Monark forks are just dangerous on a motorized bike.
Having not ridden or braked with the monarch fork, I will pay attention to the action and may well come to the same conclusion if the movement feels funny. I will also look at the Sunlite Springer, as I have been aware of the idea that heavy bike plus engine plus rider is a lot to ask of bicycle parts. So I've tried to go relatively heavy duty on the parts, and this bike is intended for a neighborhood cruiser with a top speed around 25mph, so it will hopefully be less stressed than some.

Pat, did you see my email about buying your rear sprocket mount recommended earlier in this thread?
 

sportscarpat

Bonneville Bomber the Salt Flat record breaker
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Thinking every Monark replica fork I have seen did not have a press on (larger) area for the crown race, either. Maybe that has been corrected on newer ones. If you can't press a race on it makes for a sloppy feeling fork. You may want to check yours. It's all about final adjustment on the various joints, too.
Looking at the build you acquired you will need to add a front mount and upper mount to the engine. The 200c engine has a lot of torque and will around on just a rear mount. Should be triangulated into the frame.
You mentioned a 3D manual clutch, too. They are pretty aggressive in engagement so the engine mounts become even more critical.
Sorry, not trying to pick apart your build but since you are in the early stages its easier to improve now. Lots of collective knowledge on this forum. We have all been through it before and know what works and what doesn't.
Did not see any emails.
 

woody6

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I will definitely examine the monarch races more closely when I take it apart. This is a new and purportedly 'heavy-duty' version, but what differences there are from the other ones I do not know.

I will add a forward engine mount, if I remember correctly, there is a boss on the engine that might work for that. As for the aggressive engagement, that was *exactly* what I found when I attempted a short driveway-test, which resulted in the bent and broken spokes. I was trying for a slow/smooth engagement and it didn't work that way. I had made my left-tank-side clutch lever with a long-ish throw thinking the long throw would help with smooth engagement. I'm not sure what I will do to address that, but the abrupt engagement is why I emailed you about your hub adapter.

No apologies necessary, I appreciate any and all criticisms and advice - never once thought I was the smartest one around. I'll give you a call about the hub adapter this afternoon.
 

woody6

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After many helpful tips from Pat, I am gradually admitting to myself that I need to move away from the 3D clutch.

I was really pleased with my lever operated clutch because it would both look and operate like an original. It really aids that vintage look. I've had the bike running on the stand and had operated the clutch with the back wheel off of the ground, and it felt good. Unfortunately, the engagement is really aggressive, and I broke two spokes and bent some more when I attempted a short driveway test. Pat's quality hub adapter should eliminate slippage at rhe wheel, but it can't smooth the clutch engagement.

I had somewhat anticipated the problem and I thought I could fine tune the engagement by adjusting the ratio of the lever. Unfortunately, the clutch engagement happens over a very short amount of cable travel.

I'm sure the on/off nature of the clutch is appreciated in racing karts, but it isn't so good for my project. The rapid engagement is a property of the metallic friction surfaces, and I did briefly wonder if I could modify the clutch plates with an organic material for a better feel. Unfortunately, the clutch disc that transfers the power is also the friction surface, so the only option would involve additional thickness of the plates. That would involve other changes, as well as the tradeoffs between engagement and longevity.

So I guess my clutch and custom lever are headed for the parts bin. Removal will clean up the bike, the Indian tank decal will be more visible on the left side, but it will seem a little less 'vintage' to me.

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woody6

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While you are at it Woody, please mount the front fender braces to the rear non moving fork legs.

Tom
Thanks for the suggestion, let me ponder that. I did read the threads about the front fender getting loose and causing accidents, something I definitely do not want. I'm not happy with the rear fender braces, but the front fender is solid/firmly positioned and will keep the fender at a constant distance from the tire.

I should say too that Pat told me why he doesn't like the Monarch fork, and as soon as he said it I could see the problem clearly. The braking force wants to rotate the wheel mount and unload the front suspension, a motion also assisted by the spring. He said this starts an unpleasant oscillation. I haven't experienced it yet, but when I do I will be looking for the Sunlight Springer Deluxe instead. That will require rebuilding the front fender mounts.
 
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Tom from Rubicon

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My Sunlite fork with Wald fender braces mounted to the sprung front fork (photo).
The trailing fork is arched high over the fender. Monark is just the opposite.
Got one in a box and no place to go. Additionally, the Monark is nowhere built as robustly as a Sunlite.
Pat will sell you one with all the unnecessary tabs gone.
I did it the hard way.

Tom
 

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