AirDyne Main Chain With Half Link Replacement

My Airdyne’s chain, sprocket to idler, stretched beyond the limit of the chain tensioner. The chain was noisy, rattling and clinking. When checked, the stretch was 1.5 percent and 1 percent is considered worn out. It needed to be replaced. 

I checked the information online and it seemed like a simple procedure since I have had all of the parts but the chain off the bike before. Surprisingly, my AirDyne has a different chain end linkage than the online information shows. The difference caused the project (and exercising) to a dead halt while I figured out what I needed and to get it. 

The video from the folks that sell replacement parts showed an even link count chain with a master link to join the ends. Every bike I ever had used this system; motorcycles minibikes, go carts, and chain driven lawn mowers too.  I suspect the difference is an older (online) versus “newer” (mine) thing. “Newer” being relative since I bought mine used 30 years ago. 

However, it turns out that there are two methods to link the ends of a bicycle chain. The second is an odd link count chain that uses a half link to join the ends. My AirDyne has this system. There was no master link and the entire chain was permanently pinned. It took some research on this one to be comfortable with how it works. It is simple to do, once you know what to do and have the parts.

Identify if you have a master link or a half link setup before you start working on your AirDyne. If you have the half link system, you need to buy a replacement half link and a master link in addition to the chain and chain breaker. The chain and chain tool were about $20.00. The half link and master link were about $10.00 USD. The big box store was cheaper for the chain and tool. The “local” bike store would have been cheaper for the fittings.

This Ible only addresses the odd link count chain and half link system.

There are now completely half link chains that will fit both even and odd link count chain applications. Apparently, they came about because half link can negotiate a smaller sprocket without breaking. However, expect to pay a lot more for a half link chain. Cool, but not necessary.

Tools

Chain tool (breaker, pin remover, splitter, etc). The chain tool pictured can also join (press fit) half links.

Narrow tip pliers to make seating the master link clip easier

Parts

A standard single speed, 1/2 x 1/8 inch bicycle chain with at least 69 links

One half link

One master link

Chain lube

Note: There are online instructions on how to remove the parts to get to the chain.  There are instructions on how to fit a new even link count chain. However odd link is slightly different so read the directions below.

Make sure the axle nuts and tensioner nuts are loose and the axle is pushed back towards the crank sprocket.

Use the chain tool to remove one pin from the old chain.

Remove the old chain.

Wrap the new chain around both sprockets. The side of the chain with logo faces away from the bike.

Make sure it is clearly seated on all of the sprocket teeth on both sprockets and pull it tight.

Mark the pin that when removed will result in one empty spot on the sprocket.

Remove the chain and remove the marked pin.

Press in the half link.

Wrap the chain around both sprockets. There won’t be any spaces.

Use the master link to join the ends. Put the closed end of the clip facing the direction of the chain travel (forward). Use the pliers to seat the clip.

Put a drop of chain lube on the half link and master link. IThe chain is likely already lubed.