Reddit mentions of KMC Z51/ Z8. 1 Bicycle Chain (6 & 7 & 8 Speed , 1/2 x 3/32-Inch) Packing may vary

You will need this: https://www.amazon.com/Shimano-Tourney-Mountain-Bicycle-Derailleur/dp/B00OJZQPDI

And this:
https://www.amazon.com/KMC-Bicycle-Chain-Speed-32-Inch/dp/B000AOA3PS

And some tools or a local bike shop to put it all together.

Also, clean your bike!

if you take it to a bike shop they should be able to replace the chainring and sprocket and put a chain on.

If you want to do it yourself you'll need to following:

https://www.amazon.com/Shimano-SG-3C40-Nexus-Sprocket-23T/dp/B007FOVIDW

https://www.amazon.com/KMC-Bicycle-Chain-Speed-32-Inch/dp/B000AOA3PS

For the chainring you should measure the BCD, directions here: https://wickwerks.com/bolt-circle-diameter-bcd/ This chainring works for 110BCD or 130BCD: https://www.amazon.com/Origin8-BMX-Singlespeed-Fixie-Chainring/dp/B003J7ZP9W

One small thing to note with respect to other replies is that your bike appears to have a freewheel and not a cassette. KMC Z51 is probably fine and is about as cheap as a chain can get.

With that sort of setup, many people just run them until it stops performing well and then replace the freewheel and chain together. You can replace both for the cost of a decent 8 or 9 speed chain. In any event, as someone has already said, it's probably best to ride it until the winter is over and changing it in the spring.

Hi ,

Im looking for a new 7 speed chain for my bike something cheap

Currently looking at this one

http://www.amazon.ca/gp/product/B000AOA3PS/ref=gno_cart_title_0?ie=UTF8&psc=1&smid=A3DWYIK6Y9EEQB

Had it previously on my bike it was alright but was wondering if there are more options in this price range? (Live in canada if on amazon the better!)

OK, I'm thinking we do this in stages.

Stage 1 which will allow you to get it riding now and will be perfectly capable of a 4-5mi round trip.

Cable Cutters ($20) stick to the better units but probably no need to go for Park Tool. BBB make a nice one, although I currently have an IceToolz cable cutter because I can't find my good ones.
For the brakes you will need a 4th hand cable stretcher like this Pedros ($17) unit which is a third the cost of a Park Tool unit.
Will also need cables, easiest way is to grab a DIY Jagwire ($24) kit which has both brake and shift cables.
These Vittoria Zaffiro tyres are a good compromise of value, durability and performance. I use these a lot and they're on my training bike. Will also need tubes, and being a commuter, flats are not your friend so these Schwalbe tubes are a good idea. ($60)
Arundel cork bar tape ($20)
A new chain for your bike is probably the only way forward, and this KMC is perfect ($6)
The brake pads on your calipers will now doubt be old, and also a 30yo pad compound, so not overly efficient. Would strongly recommend these Kool Stop Continental brake pads as a starting point before we get to Phase 2 ($10)

Grease for the Bottom Bracket and Headset (and wheel hubs) is also needed, but there's absolutely no need to buy bike-specific grease, so this Valvoline tub as an example would be ideal ($10) .
The chain needs to be lubed, and in dry conditions I like Finish Line dry lube. Others will have their own preferences, but this is a good starting point.

Also should think about replacing the saddle, but this is very subjective and not something that can be recommended in terms of which saddle to buy. Maybe scoot around Craigslist for your area and see what comes up..

In terms of learning the skills, the Park Tool video channel is surprisingly good although heavy on product placement and endorsement although this is to be expected. There are lots of alternatives to Park Tool tools though, including Pedro's, BBB and others. None of the skills associated with your era of bike are all that difficult, and refurbishing this to be usable in your context is completely feasible in your garage.

May also want to consider buying one of the entry-level bike toolkits like this tool kit as a starting point ($40) although this is just an example however is the same kit as others sell just rebranded.

So phase 1 (not including the tool kit) is about $160-ish and watching a bunch of videos.

sorry for the essay, but once I started it just sort of kept going. Phase 2 is removal of existing driveline, and upgrading to a Shimano 2x8sp indexed group with modern dual pivot calipers and modern alloy wheels. But we can cover that later.