Question about Sear Spaceliner chain

[Suddenly it’s 1960!]

Hi,I was wondering if anyone here could tell me the factory correct chain size/length for the Sears men’s 26” spaceliner. Thanks.

 

[bloo]

Assuming that it has no derailleur (I believe they were all one speed, right?) then 1/8" chain, 1/2" pitch. Chains aren't sold to length anyway, so you'll have to cut it, easiest and best way is with a chain tool. Just get a chain long enough.

There's 2 ways to count links on a half inch chain. One way has one wide plus one narrow = 1 link. The other way has every link, wide or narrow, counted as a link. All chains I have seen recently have been advertised the second way.

If you don't have an old chain to measure, or there is some doubt, put the wheel in and lock it down pretty far forward in the rear forks or dropouts. Check that the wheel fits in the fender pretty nice, knowing that is it going to go back as the chain wears or stretches. Slightly too far forward is better than slightly too far back.

Now measure from the center of the axle to the center of the crank in inches. Multiply by 2 to account for the top and bottom run. Multiply by 2 one more time to convert from inches to half inches. Remember this number.

Count the teeth on the chainwheel and the teeth on the rear sprocket. Add them together. Divide by 2. This gets you the rest of the distance the chain has to cover in half inches. Add the number you get to the other number from the last step. This is the number of links. Add an extra link or two to allow both for the fact that this method ignores the angle of the chain, and for Murphy's law. Get a chain at least this long.

Wrap it on the bike and it should almost fit. Cut it taking into account that the wheel will move back a little when you tighten the chain, and you probably need the wheel fairly far forward in the slot. Don't forget to count the master link. Don't forget when you cut that you need the chain to have a thin link sticking out at both ends so the master link can attach.

 

[Suddenly it’s 1960!]

Thanks for all the info. Yes,the spaceliner is 100 per cent stock. Bendix hub single rear gear. I didn’t realize there was so much to know about chains. Just curious,why is it better for the rear wheel to be slightly more forward than to the rear? Is it because the slot in the dropout slopes upward as it goes back?
I don’t have tools to cut a chain. Guess it’s best for me to take the old chain to a bike shop.

 

[CURTIS L LINDGREN]

Axel sitting slightly forward in the slot allows for the chain to stretch during use. Glad you found a bike to work with.

 

[Archie Sturmer]

Also available are some 1/2”-pitch “half-links” which are sometimes useful, and ensure more even wear on chain rings and sprockets with an even number of teeth.
I believe that Murray may have used an even 46-tooth front chain ring sprocket, but not sure about the rear, (as I swapped mine out for a larger 24-tooth SA cog sprocket)?

An additional half-link would add one half inch to the length of a chain.

 

[Suddenly it’s 1960!]

Axel sitting slightly forward in the slot allows for the chain to stretch during use. Glad you found a bike to work with.

Thanks! I still haven’t found the early style Deluxe 26” men’s 2 speed spaceliner but was lucky enough to find two local 26” men’s “Forward Thrust” models,one chrome deluxe 2 speed model 46922 and one red painted model 46305. I alternate between riding the two. Amazingly both were all original and plastic tanks and lenses were in excellent condition. Sadly the person who owned the red painted one had thrown out the bulb holder/battery tray because it was rusted from someone leaving batteries in it for 50+ years.

I’m sure the chain on the red one is stretched because it’s looser in some positions and tighter in others,that is,the amount of chain deflection varies depending on sprocket position.

 

[Suddenly it’s 1960!]

Also available are some 1/2”-pitch “half-links” which are sometimes useful and ensure more even wear on chain rings and sprockets with an even number of teeth.
I believe that Murray may have used an even 46-tooth front chain ring sprocket, but not sure about the rear, (as I swapped mine out for a larger 24-tooth SA cog sprocket)?

An additional half-link would add one half inch to the length of a chain.

Thanks,I will count the teeth on the sprockets when I get home.

 

[CURTIS L LINDGREN]

Sadly the person who owned the red painted one had thrown out the bulb holder/battery tray because it was rusted from someone leaving batteries in it for 50+ years.

You might try @shawnatvintagespokes ( here on the Cabe )for the battery tray and light set up. Shawn and her husband Earl have fixed up many of these set ups . They may have one or know where to get one for you .