Bicycle Mechanics - Chain length for a single speed (46/19)

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NWrighteous
11-20-09, 02:41 PM
Hi, all -

I've been rebuilding and repairing a garbage-picked Huffy English 3-speed. Project bike. The rear hub is a Shimano, not the classic SA. It's been baptism by fire - learning how to do it as I go.

Right now, I'm working on the chain. My problem is trying to figure out the length chain I need. There wasn't a chain when I found the bike. I have a few spare 1/8" single speed chains (for, like, a BMX bike) that I've decided to use for this 3-speed. But each is about one-half link (or, I guess, one link) too short to fit on my 46/19 chainrings on this 3-speed. I have a master link, too, and some spare 1/8" link sections lying around.

I'm not sure if I should add a whole link to the chain I'm using, go out and buy a new chain, or slide the rear wheel forward in the dropouts to compensate for the half-link short. Will extra slack with a whole additional link be a huge problem? I'm not well-versed working on single-speed bikes, and don't want to bastardize a chain that may break one day by adding links to it.

Not exactly sure what other information you need to shed some light on this, so let me know if I can post more info about what I'm working with. Thanks in advance.

Yellowbeard
11-20-09, 02:49 PM
The chain's not supposed to be long enough for the wheel to sit all the way rearward. Ideally, for a bike like this, you'd want the longest chain that fits that requirement. You tension the chain after it's already on the sprockets by moving the wheel rearward in the dropouts, so just get a chain on there that lets you install the wheel.

As long as the wheel isn't right at the front of the dropouts, your "half-link short" chain should be ideal.
NWrighteous
11-20-09, 03:18 PM
The chain's not supposed to be long enough for the wheel to sit all the way rearward. Ideally, for a bike like this, you'd want the longest chain that fits that requirement. You tension the chain after it's already on the sprockets by moving the wheel rearward in the dropouts, so just get a chain on there that lets you install the wheel.

As long as the wheel isn't right at the front of the dropouts, your "half-link short" chain should be ideal.

Right on, thanks for the tip. I'll give it a whirl.

jacksbike
11-20-09, 06:12 PM
Bear in mind also that as you pedal on a single speed or three speed, there will be normal loose and tight spots for the chain. You do not want the chain to have a very tight spot in which it feels hard to continue to push the pedals. A BMX bike chain is a lot shorter than an adult bike chain. The rear wheel should be located about 1/2 way in between the rear dropout.