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View Full Version : problems with chain length?



TobyKenobe
09-07-2008, 06:24 PM
Hello
This is my first post, hello to everyone! I just completed a pretty poor version of the spinbike. i think i used the wrong sized forks so only the tall people can reach the pedals, plus i had to re wled the t bar and moved it so now the trike is too short and will only spin not go in a straight line at all. Still i have enjoyed this project and ohpeto build some more. great book by the way.

Anyway i am having problems getting the chain length correct- to have the chain length correct i would need to join 2 wide pieces together, not a wide to a narrow if you get what i;m saying?! Can you buy a link that has a outside peice on one pin then a inside tpye for the other pin. that doesnt sound vary clear but without a drawing maybe i cant explain...

Toby

greenevegiebeast
09-07-2008, 06:39 PM
toby what are you putting a chain on you might be able to usea slightly longer chain and use a chain tensioner.:D

TheKid
09-07-2008, 09:04 PM
You can simply add the one link so you have it correctly matched, with 2 side plates (Wide) to a link with the plates connected on one side (Narrow). To get the right length initially, run the chain around the rear sprocket in a way that one end of the chain is on the middle of the front sprocket on top, goes back and around the rear sprocket, returns to the bottom of the front sprocket, and goes around the front sprocket until it overlaps the other end of the chain by one link. Make sure one end has the plates with a pin, (Wide)and the other just has the center link. (Narrow)

AtomicZombie
09-07-2008, 11:00 PM
What you are defining is called a "half link". The problem is that they do not make these for bike chains.

Make the chain as short as you can and then slip the front wheel down a bit in the dropout to pick up the slack.

Brad

TheKid
09-08-2008, 01:23 AM
I forgot all about the half links, but Brad's method is faster and cheaper.
If the occasion arises that half links are absolutely necessary, you can get them here:

http://www.ebikestop.com/kmc_12_link_for_18chains-CH4102.php

http://www.ebikestop.com/kmc_12_link_for_332chains-CH4104.php

savarin
09-08-2008, 04:27 AM
What you are defining is called a "half link". The problem is that they do not make these for bike chains.

Brad
You can now:p
http://www.sheldonbrown.com/harris/chains.html
and for wide chains
http://www.sheldonbrown.com/harris/chains-wide.html

AtomicZombie
09-08-2008, 08:11 AM
Hey, great to know the option is there. I needed a cycle chain half-link when I was doing this robot project once.

Brad

SirJoey
09-10-2008, 07:15 PM
Also available here: http://www.danscomp.com/463011.php

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif