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Skiptooth sprocket question


Discussion at Motorized Bicycle Engine Kit Forum in the Board Trackers and Vintage Motorized Bicycles forum. I had the good fortune of finding a pre war skiptooth 26" Schwinn DX cruiser at the dump the ...
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Old 09-28-2009, 10:40 PM
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Default Skiptooth sprocket question

I had the good fortune of finding a pre war skiptooth 26" Schwinn DX cruiser at the dump the other day and as close as I can guess from reading up on it the year would be somewhere from 1940 to mid 40's. I'm been staring at it since figuring what to do with it since the frame and fork are really nice , the handlebar is in good condition and the seat just needs new leather and cleaning up. The DX was a budget model at the time, but still was a pretty cool bike. The tank is missing, fenders and chain guard as well. I sat an 80cc HT in the frame and it is tight, but I think with a slant head it will fit. I think I'd like to keep the bike pretty much original without going crazy with a real restoration and will be on the lookout for a chain guard, rear rack and tank if I can afford it. Here's where my question is regarding the pedal crank sprocket. It is a skip tooth and the wheels I intend to put on it are going to be modern heavy duty rims from bikeworldusa, 26 by 2.125. The sprocket is pretty cool and is called a "sweetheart" due to the heart shaped cutouts. Since it is a kind of signature thing with this model it would be nice to keep the sprocket even if I change the crank to something shorter to accommodate the engine clearance issues.Now, to the point... does anyone know if you can use a regular cruiser chain with a skip tooth sprocket and a wheel sprocket which is not skip tooth? I'm guessing not, but hoping you can. Or can I use a skip tooth chain if it will work with the wheel sprocket? Does anyone know? Since this will be a motorbicycle I don't anticipate a whole lot of pedaling, but it still has to be able to be pedaled.
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Old 09-28-2009, 10:47 PM
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Default Re: Skiptooth sprocket question

If its 1" pitch then 1/2" pitch chain will work without issues.

Width would be your only problem.

I an recall old fixed wheel track bikes having these chainwheels for weight saving reasons. The chain was normal as was the rear cog.
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Old 09-29-2009, 12:35 AM
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Default Re: Skiptooth sprocket question

I have asked about using the skip tooth chains at a local antique bicycle store.
What I learned was:
If you can get ahold of a rear sprocket that has an even number of teeth, you can file down every other tooth and keep the skip tooth chain if you want to.
Standard bicycle chain is 1/2 pitch. Skiptooth chains are also known as "inch pinch" chains.
Do the math.
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Old 09-29-2009, 12:39 AM
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Default Re: Skiptooth sprocket question

i know from experience that a regular 1/2" pitch chain will NOT work with a skip tooth (1" pitch) sprocket. two totally different animals. the skip tooth chain has two different links, alternating 1/2 link, then 1' link, repeating... a newer 1/2'' pitch chain will roll right off, jam up, or break.

i've been down this road before and i've tried just about everything imaginable.

here's some options for it that you're just gonna love...

the easiest thing to do, would be to buy a "newer" sweetheart sprocket with the conventional 1/2' pitch. you can get one here for 6.95. Pedals ~ Sprockets ~ Cranks

that way you can use a new chain, the new sprocket on your wheels, and everything would be nice and modern, and simple.
but who wants to take the easy way out?

so, the first thing you have to do is find a skip tooth, inch pitch chain. if there's one rusted to the bike already, you're in luck. soak it in oil for awhile.
if not, ebay always has them. they usually go for 50 bucks for an old stretched out one, to 100+ for NOS.

that's the easy part. it just takes money.

now, for the rear cog (sprocket).

i've done both of these on a bendix coaster brake, and they both worked.

the bendix cog has three nubs that slide into grooves in the hub, and then are held in by a snap ring.
you can find an old skiptooth cog with the same inner diameter to fit over the hub. find one with just a round hole, no nubs.
then, weld on three nubs to match the hub. install, and ride around.

this one's even more fun.

buy an extra rear cog to fit your bike, make sure it has an even number of teeth, then grind every other one off. make sure you quench it in water after each tooth, or whenever it gets really hot, so it doesn't warp.

the only problem with this method (besides the mess, the time, the P.I.T.A. factor,) is if your using an old chain, the new cog teeth might not get along with it, so you might have to do some extra grinding and filing of the teeth. but, inch pitch chains are remarkaby strong, and don't stretch anywhere near the amount as the newer 1/2'' ones do.

here's things that WON'T work.

-switching the guts from another hub into your new one (unless you find the "holy grail" hub that i never could.)

-inch pitch chain on 1/2" pitch sprocket, and vice versa.

-finding an old rear cog that matches the one on your new back wheel, and fits right on (another "philosopher's stone".)

i don't have the bikes i did this to, so sorry, i don't have pics.

but i do have a brand new 18 tooth (equal to a 36) WALD skiptooth front sprocket, inch pitch chain, and an 18 tooth bendix rear cog, which will soon be grinded down to a 9...

hope this helped.
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Old 09-29-2009, 06:52 AM
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Default Re: Skiptooth sprocket question

Thanks to all for your responses. Well, I'd say this doesn't look too promising. No, there was no chain with this bike. If I really wanted the sweetheart sprocket, as you say I could buy a new one with the proper number of teeth, or forget about it and use the sprocket from a post war Schwinn, which would at least be old, good quality and Schwinn. I do have one of those from a middleweight American. Nothing is ever simple, is it?
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Old 10-03-2009, 03:19 PM
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Default Re: Skiptooth sprocket question

I just took a look at the auction results from that sweetheart sprocket and crank on eBay. It ended at $68.58! Incredible... I'm listing mine tonight and with any luck may fetch a similar inflated price. Pretty good from a free bike. That would just about cover new heavy duty rims.
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Old 10-03-2009, 03:38 PM
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Default Re: Skiptooth sprocket question

Saw an Elgin on ebay (I think, it was late last night) that someone had actually turned a regular sprocket into a skiptooth. Would have looked more convincing except it was just a blank sprocket, it definitely wasn't an inch pinch chain.
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Old 10-03-2009, 05:11 PM
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Default Re: Skiptooth sprocket question

i'm almost positive schwinn made a sweetheart sprocket after the skiptooth, modern style. i'll keep my eye out for ya.

did you say you ordered the wheelset from bikepartsusa? i just got mine. weinmann alloy rims, 12 guage stainless spokes, and shimano hubs. they're pretty good, the silver anodizing isn't that great, it's kinda cloudy, and there's a splice where the rim's put together, and the spokes don't seem to be seated all the way, although they're tight.

for the price, they can't be beat. and i've ridden on them for the last day and a half, probably 70 miles worth, and they're smooth. we'll see how they hold up.

oh, back to the skiptooth. last week i checked out ebay around 3 in the morning, and there was an NOS diamond inch pitch chain, buy it now, for 25 bucks. needless to say, it's mine. i got it yesterday.
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Old 10-03-2009, 05:16 PM
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Default Re: Skiptooth sprocket question

Here ya go silverbear,



HEART SPROKT JS-S46 46T CHROME $8.99
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Old 10-03-2009, 06:17 PM
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Default Re: Skiptooth sprocket question

That's NOT a DX frame... it's a straight bar! (Panther, Hornet & such...)
On a DX, the middle bar has a slight upward curve to it.

It's a very nice find!!! Congrats. Keep the original paint!!!

It should be easy to find a skip tooth chain & rear sprocket for it.
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Last edited by Venice Motor Bikes : 10-03-2009 at 06:21 PM.
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