Reddit reviews KMC Z-72 7-8sp chain (Silver/Gray)

Nice find! I even raced one of these for a bit. It seems like it's been sitting for a while. I would replace:

• Tires: Get the biggest tire that'll fit.
  
• Brake Pads: This bike looks like it's been sitting. The rubber in the pads is toast. Get some Kool Stops
  
• Chain: Never trust an old one. KMC makes solid stuff.
  

OK, so you've got a Shimano TX71 crank up front. That's pretty low-end, and I don't think the rings are replaceable, so if they're worn out you'll need a new crankset.

The rear set of gears is called a "cassette" (in your case, older bikes had freewheels). It's a 7 speed Sun Race 11-32.

The chain is chain...no big deal on that as long as it matches your cassette. 7 speed chain should be used with 7 speed cassettes. 8 speed chain is the exact same as 7. 7/8 are the same width, etc. 9 speed chain is narrower, weaker, and wears out faster, and it costs more than 7/8. 10 speed chain is again narrower, weaker, etc. And again for 11. Anything above 8 speeds is silly, especially on anything other than actual racing bikes. It's just more money and trouble, so please don't buy in to the marketing gimmick of 10/11 speed "upgrades", I promise you they won't actually make your ride better.

My opinion said, let's move on to replacing these worn out parts.

Let's start with the crank. You'll need some specialized tools to work on this, but they're not too expensive and a worthwhile investment. You'll need a square-taper crank puller, such as the Park CCP-22. That's needed to remove the cranks.

Next you'll need a tool to remove the bottom bracket (the bearings/spindle bit the cranks attach to. Yours is probably pretty worn out. The thing with BBs is they come in many lengths, such as 122mm, 118mm, etc. The length is determined by the crankset you use, not by your frame, so if you replace your crankset, chances are you'll need a different BB length. Also, many newer cranksets have built-in BBs, since, like I said, BB and cranks are pretty tied together. You'll need to get your old BB out, and you'll need a BB tool for that. Chances are your BB would be one compatible with the Shimano 20 tooth 'Isis' style: BBT-22. You can tell if this is the case by looking at your bike. Behind the crank you'll see a the outside edge of the bottom bracket, if it's got a bunch of small indentations like this, then it's an Isis style one.

Now you'll have the old crank and BB removed. Next you'll need to get a replacement. I'm not sure your budget, so I'll just go with some 'middle of the road' recommendations. This is what I have one some of my bikes: Race Face 22-32-44 Crankset and BB. This is a pretty good deal, since it's a fairly nice crankset AND it comes with its own BB, so you don't have to get that separate. The BB included is an outboard bearing style, which will be a bit different looking than your old one, and require another tool, as it's not compatible with the BBT-22. It requires an outboard bearing wrench like the BBT-29. Even after purchasing this extra tool, the Race Face crankset is an exceptional deal.

Alternatively, you can source out a square-taper style crankset replacement (like your old one), and if you luck out, your old BB will be in ok enough shape and be the right length. Chances are that's not the case, and you'll need to replace the BB too, and end up spending just as much as that RaceFace. The one minor issue with the Race Face one is it's slightly smaller than your stock one, and I don't know if your T30 is one of the ones with a cover over the chain, and if so, there may be a slight gap if you used a slightly smaller crank. If you don't have a chain cover, this wouldn't be an issue, and going from 48 to 44 would probably be an improvement, unless you often ride really really fast.

Next you'll need a rear cassette. Your stock cassette was an '11-32'. This means your smallest sprocket was 11 teeth and largest was 32. When combined with a 22/32/44 crankset, a cassette with 32t as the largest gear is a real 'stump puller'. The 22:32 ratio is probably MUCH lower than you'll ever use, unless you routinely climb mountains on your bike. I'd recommend something a bit 'tighter' such as 11-23 or 11-25. Unless you're REALLY fast and routinely in your largest gear in the front and smallest in the rear, going over 25MPH, I'd also suggest not getting a cassette with an 11t small gear. I'm pretty fit and very very rarely 'spin out' my fastest gear, which is 44:12 for me. 44:11 is a good bit faster a gear, but I'd guess you don't actually need that sort of gear. The choice is up to you, but I recommend these cassettes: 11-24 or 12-24 and 11-28 or 12-28. Dropping the range down from 11-32 to 12-24 means you'll shift your front gears a bit more often, and in return, you'll have a better spread of gearing options, with more usable gears and less duplicate gears. I highly doubt you use more than 44:12 and less than 22:24 ratios as it is, as those are pretty damn fast and pretty damn low gears.

You'll need a cassette tool to remove your old cassette and install the new one. FR-5 Cassette Tool, and you'll also need a chain whip: SR-1 Chain Whip.

As for the chain, any 7 or 8 speed chain will work. I recommend this one: KMC 72. Shimano chains are GARBAGE and wear out way faster than other brands. SRAM chains are ok. Wipperman are good and KMC is good.

All of these tools have videos on their use on Park's website, and are available on Amazon for reasonable prices. If you want to save a few bucks, there's some non-Park versions of said tools for cheaper. I have a Topeak brand chain whip, for instance, and it's every bit as good as Park's.

Let me know if you have any other questions. Hopefully this long post helps.

>Change out the old cassette with a new Shimano HG-50-7-- will this even work on a road bike? 12-28

That depends on your rear derailler, but it will probably work.

>I need a chain to go with that.. thinking Shimano CN-HG-70-CS

half the price and the reuseable master link is nice.

Take a look here for your cheap CXP 22 needs. The cxp22/2200 (in silver) is $109 with ~$17 shipping vs Bicyclewheels' $145 + $50 shipping.

If I were you, I'd just stop now and save your money for a better bike. The Schwinn Varsity weighs 42 lbs, or about 12-18lbs over what even a generic chromoly framed 80s road bike would weigh, and given that you can pick those up pretty cheaply on craigslist, I'd trade it in and go that route.

But assuming you're already sentimentally attached to this one, despite the fact that it weighs about two full gallon milk jugs more than a bike needs to, you're going to need to start with a 1 piece to 3 piece adapter, like this American to Euro BMX adapter.

Then add a generic road double crankset in your desired length and the appropriately sized bottom bracket, and a fresh chain cut to the right size.

Other than that, it's basically a question of taking the old parts off and putting the new parts on and transferring the pedals over.

Marlin 5 looks like a 7 speed. So pretty much any old chain will work fine.
https://www.amazon.com/KMC-X8-93-Bicycle-Chain-7-3mm/dp/B001MXQHPG/

*edit, this one is $2 cheaper.
https://www.amazon.com/KMC-Z-72-7-8sp-chain-Brown/dp/B001CN6QA2

It is a 3/32 7 speed KMC Chain.

You need an 8-speed chain. They're cheap--here's one for under $10--so buy one and be done.

Get a chain tool while you're at it, because you may need to remove a few links. Lay the new by the old to decide where to remove extra links.

In the future, store the bike indoors when you're at home, no matter how inconvenient it may be. Otherwise, everything made of steel will rust and turn to shit.

$32 for a chain is a bit high.

Amazon sells KMC 8 speed chains for $9 and free shipping.

You'll probably also find big chainrings a lot cheaper on Amazon.

Not sure which model Novara you have, but you can find 8 speed cassettes on Amazon for around $15 depending on which one you need.

Come to think of it, I buy just about everything replacement part wise off Amazon.

If the pins and internals of the chain are rusted, when the rust is removed there will be some slop. I do agree that if the whole drivetrain is worn, your better off just freeing the chain so you don't have to replace the cassette too. But if the cassette isn't worn, I'd just replace the chain.

Without getting into the LBS debate, I buy chains online. My old LBS charged $40 for an 8 speed chain. They're less than $10 online. I'm not gonna make my college student friends pay $30 extra to support the LBS. $10 speed chains have a similar markup as well. I find many shops don't carry the basic KMC chains which I prefer.

http://www.amazon.com/KMC-7-8sp-chain-Silver-Brown/dp/B001CN6QA2/ref=sr_1_1?s=sporting-goods&ie=UTF8&qid=1413374754&sr=1-1&keywords=8+speed+chain

http://www.amazon.com/KMC-10-Speed-116-Links-Bicycle-28-Inch/dp/B001AYOP9M/ref=sr_1_11?s=cycling&rps=1&ie=UTF8&qid=1413374848&sr=1-11&keywords=10+speed+chain