Tonycycling

My bike is a 1989 Performance Vitesse, with a Biopace 52/42 front and 13-28 6 speed cassette.

While searching other threads, I found that the SRAM PC-830 was suggested and/or recommended. After buying it, I discovered that my original UG labeled chain is 1/8" while the one I just bought is 3/32". A 1/8" chain is available which is the SRAM PC-1 (made for single speeds).

Question: Should I go with the new chain PC-830 I already bought or just get a new 1/8" chain?
Is it strange that I got the 1/8" back then?

Thanks.

HillRider

Your 6-speed freewheel or casette, assuming it was "standard spaced" may tolerate a 1/8" chain but a 3/32" is the correct one. I wonder if the 1/8" chain was a replacement and the purchaser made a mistake. Typically, 1/8" chain is only used on single speed/fixed gear road and track bikes.

Panthers007

Yes indeed - the 3/32" chain is what it should have had all along. Forget about 1/8" - as stated they only do duty on fixed-gear and some BMX bikes.

operator

A 6-speed uses a 3/32 chain. 1/8 is wrong.

GRedner

I intentionally run a 1/8" chain on my 6-speed freewheel, because they work fine (if a tad noisy) and I bought a few by accident that I want to use up. But as for the OP, use the 3/32".

meb

The Cyclo Sturmey 2 and 3 cog freewheels that mounted to the Sturmey 3 hubs came with a special wide derailleur for to use the 1/8 chain. Are you saying standard 5 or 6 speed derailleurs will work with 1/8 chain and there was never a need for a wide derailleur to begin with?
Is there any snagging or shifting problems?

griftereck

you must have long chainstays. As the more sturdy 1/8" chain wont be bent by the deraileurs so easy. I couldnt get a 1/8" chain to work on my 6 speed bmx.

meb

Well I measured the width between the cage of an Shimano Alvio rder and find it just under 1/2 inch wide-so it looks the rder can handle 1/8 inch chain.

Gredner, what bike(s) have you been running 1/8 inch chain on 6 speed.

meb

Let's extend this concept further-has anyone got 1/8 chain to work on a 7 speed derailleur system?

I_bRAD

How wide is the chain? 1/8 refers to the inside width, then you have to consider the plate thickness and pin length. Add to that the fact that the top pulley "floats" on an alivio derailleur for SIS purposes and I wouldnt' be so sure it'll work.

GRedner

The bike is an '86 Centurion LeMans RS. The rear derailleur is original as far as I can tell: https://www.disraeligears.co.uk/Site/...(L525_SS).html That page says the derailleur is designed for 3/32", but it seems to work fine with 1/8". YMMV!

meb

As measured through the clear package, a 1/8 chain I haven't mounted yet appears to be about 3/8 wide at the pins. With the float I guess I could see some issues. My recollection is that the pre index shifters also had some float on that wheel, or is it more on the idexed shifters?

Tonycycling

Update: I installed the correct sized chain, 3/32". It sounds better overall. But now I'm having shifting problems.

The chain length was measured and calculated to be 54 links. Being the smart-ass that I am, I decided to 53 links. Why? Because of the advantages I read on epicidiot.com -
Disadvantages: (Read and heed these warnings)
You will not be able to use big cogs (rear wheel large granny gears) with the big ring (front fast gear).

• If you try to shift into the now illegal big ring combinations, you risk breaking your chain, derailleur, hanger, etc.
• If using the shorter derailleur cage, if you try to shift into the now illegal granny ring combinations, you risk dropping your chain due to the excess slack.
• Do this at your own risk!

Advantages:

• Crisper, faster, more reliable shifting.
• Can use a shorter rear derailleur cage.
• Less chance of over shifting (changing two gears when you only clicked one gear at the shifter).
• Less chain slap.
• Less chain weight.

I'm going to add the 1 link to see if that helps w/the shifting problem. I just may be the idiot here.

Jeff Wills

I would never, ever, ever, ever, EVER run a chain that's even one link too short. Breaking off a rear derailleur hanger are just too expensive to risk it. You can say that you're good enough to never shift into the big/big combination, but I've known expert riders/mechanics who have done this and suffered the consequences. Anybody can go brain dead during a hard effort.

What short of shifting problems are you having?

ogbigbird

yeah, never run a chain thats too short. id definatly add a few links. now as for these illegal gear combinations, are they kidding me?

Tonycycling

I have to agree that the disadvantages outweigh the advantages in the case.

The shifting problem I'm experiencing is, it goes one way but not so much the other way.