Mountain Bike Reviews Forum banner

1 - 7 of 7 Posts

·
Cyclist
Joined
·
493 Posts
Discussion Starter #1
Howdy fine folks,

On yesterday's ride, I broke my SRAAM PC-1 chain. I figure I rode it for 8-9 months. It's the first 1/8 chain I've run and I was pretty pleased with it since I broke 8/9 speed chains almost monthly before that.

My question to you: Is 8 months, maybe 300-400 miles good wear for this chain?

I put another SRAAM PC-1 on it last night (my spare). I'm going to replace my spare. Any reccomendations?

Anyone using KMC? Drop buster? Gold? KMC K710 with those funky side plates?

Thanks for your answers.
 

·
Medium?
Joined
·
6,724 Posts
Good question

er, at least topical for me.

I got a pc7x about 15 months ago. I'd guess it has about 2000 miles on it. 8^) About three months ago, it started breaking links and rollers, so I was replacing them one at a time. The other day I was prepping for a ride, and I noticed two adjacent rollers missing, and I was on my last couple of spare links, so I went to the LBS to replace it.

I decided on a KMX Zchain, which is a pretty standard 1/8" bmx chain, for $10.

What's pretty funny is that the old chain was stretched 1/2 link over its length.

Of course then I had to replace my chainring and my [sniff, sob] eno freewheel. I'm going to call tomorrow to see what it will cost to service and press a new cog onto it.

Afterwards I rode a loop at Demo Forest on a 36:18 gear. There was one hill that I didn't clean, that I sometimes do, but I toughed out the rest of it. It was more fun on the flat parts, and less fun on the climbs. I was probably a little faster overall, but I made up for that with more resting.

My next drivetrain will be 34:18 or 36:19, as opposed to my previous 34:19.
 

·
Registered
Joined
·
1,163 Posts
I tried the KMC chains but they wore very quickly ("stretch"), I got a PC-7x and have been running for a couple years (Thousands of miles).
 

·
Registered
Joined
·
83 Posts
Does a 1/8" chain fit with a bash guard? I am thinking of putting a PC-7x but am worried about hitting the guard on my Truvativ SS crank
 

·
Retro Grouch
Joined
·
2,091 Posts
My take on chains..

striker said:
Howdy fine folks,

On yesterday's ride, I broke my SRAAM PC-1 chain. I figure I rode it for 8-9 months. It's the first 1/8 chain I've run and I was pretty pleased with it since I broke 8/9 speed chains almost monthly before that.

My question to you: Is 8 months, maybe 300-400 miles good wear for this chain?

I put another SRAAM PC-1 on it last night (my spare). I'm going to replace my spare. Any reccomendations?

Anyone using KMC? Drop buster? Gold? KMC K710 with those funky side plates?

Thanks for your answers.
Submitted for your approval...

Traditionally single speeders used 1/8 inch BMX chains, since most single speed (SS) bikes are just 26“ wheel BMX bikes anyway. Other reasons include the fact that SS track bikes and old BMX bikes had 1/8 inch cogs and chainrings and since 1/8 inch chains looked bigger than 3/32 chains they must be stronger. Also 3/32 (7-8-9 speed) multi-speed rated (MSR) chains are designed to derail, something you don’t want to happen on a SS bike. A second look however shows there had been a lot more R&D money thrown at MSR 3/32 chains by Shimano and SRAM, so most 3/32 chains meet or exceed the tensile or “pull” strength of 1/8 inch chains. Since most single speed components available today come in 3/32, it seems logical to use 3/32 chains. On the other hand, while some claim that 1/8 inch chains on 3/32 gears cause more noise and wear than 3/32 chains, the jury is still out on this matter as many more use prefer this set-up. In the real world, it would seem the use of 1/8 inch chains work fine on 3/32 components and some, such as the SRAM PC-7 and KMC Kool chains are stronger.

One issue that comes up from time to time is the use of ½ links. The use of a ½ link allows you to vary the chain length by ½ inch intervals, rather than one inch with a standard link. This comes in handy when you are trying to convert a bicycle with vertical dropouts. 1/2 links are very plentiful in 1/8 inch and very rare in 3/32 inch (try spicercycles.com).

So do you need a single speed (non MSR) over a MSR chain? No, not really. Is there any advantage to a 1/8 inch chain? Yes, there can be if you have chainline and/or derailing problems a SS chain can help; and as I said before some are stronger. However if you are using a tensioner such a Surly Singleator a 1/8 chain may not work.

The tensile strength of a SRAM PC-7 is about 2500 ft lbs and only come in 1/8 inch (and pimp gold); all other MSR SRAM chains (including the PC-58) are around 2023 ft lbs. The KMC Kool chains rate at 2860 ft lbs and come in both 3/32 and 1/8inch. The KMC Z chains (with an H in the model number) also come in both sizes (i.e. the 3/32 Z610H; my choice of chain), rate at 2640 ft lbs and are a bit lighter than the Kool chains. KMC ranks most if their MSR chains at 2314 ft LBS; I have not seen any published data for Shimano chains.

So what chain should you buy? There is a plethora of 1/8 inch chains out there; one of the favorites is the SRAM PC-7. KMC also makes a line of 1/8 inch (or 3/16 inch if you dare) and 3/32 SS chains. They come in various weights and strengths so you pay your money and make your choice. As far as MSR 3/32 chains go SRAM PC-58 seem to be popular with the anti-Shimano crowd as are the KMC chains. Shimano wise any of the better 7/8 speed HG or IG chains will work; The 9 speed and especially the new 10 speed chains may not work with some BMX cogs and SS chainrings.

As a final caveat there is the question of longevity aka “streaching”. Regardless of what you hear, all chains get longer with use (I’d call that stretching). There are so many factors that go into this “lengthening”, that it’s futile to try and rank one chain over another. Just try and keep your chain clean and lubricated and when it has stretches 1/8” over a foot, replace it.

Also checkout http://www.63xc.com/gregg/gregchai.htm for some good chain spew.

1G1G, Brad
 

·
Registered
Joined
·
478 Posts
I can't wait 7/64" drivetrains become standard!

Excellent summary!

However, to further muddy the water, we should also point out the perspectives of two single speed icons which have equally enlightened ideas on this very subject.

Sheldon Brown (Owns more single speeds than most.) --
http://www.sheldonbrown.com/fixed.html#chain

Wakeman Massie (Surly, need I say more?) --
http://www.63xc.com/wakem/wakedriv.htm

Of course, who doesn't love a debate which has no right answer despite all the engineering, rationale, and philosophy we can throw at it?

dd..'''
 
1 - 7 of 7 Posts
Top