atp

My road bike’s gear shifting’s getting lazy, so I decided to change my old 8 speed KMC Z chain to Sram 8 speed chain (PC-68). My bike’s got veloce triple group set. After changing the chain, I got so many problems:
1. Front derailleur can’t shift the chain to the smallest chain ring, after taking a close look; it seems that the seat tube blocked the derailleur’s movement, stopping it shifting inwards. Now I don't what to do, because before changing the chain, I could definitely shift to the smallest chain ring!
2. Rear derailleur: when I shift to the smallest gear, the upper roller almost have contact with largest sprocket, so the chain’s squeezed in the middle, and making some strange noises.

So, any ideas guys? Any info. would be appreciated. Or shall I try to get another KMC chain?


Cheers!
Z

atp

Also, The sram chain's got power link, they were easy to install, but now I can't separate them anymore!!help!

roadfix

The chain has absolutely nothing to do with the symptoms you described above, for the most part. Are you sure you have enough links in your new chain?

atp

Yes, I put the chain on the largest chain ring and the largest sprocket made sure it was long enough.

Al1943

Lazy shifting is usually a sign of excess friction in the cables or dirty shifters, probably has nothing to do with the chain. You should replace the chain when a 24 pin length measures 12 1/16th inches or sooner if possible.

Al

atp

the Z chain was obviously wore out, but I just don't know why I can't shift to the smallest chain ring. Actually I changed cables before I changed the chain, the cables went through cable housing smoothly, so I assumed that the chain and the cassette were the cause of the lazy shifting. So I ordered the new chain, and installed it, and then I got all these problem...

Al1943

Go to the Park Tool website, find the instructions for derailleur adjustments, start at the beginning, go through all of the steps in sequence, and don't leave any steps out.

swifty

First of all, screw in you B-tension screw a bit so that your pulley does not interfere with your largest cog anymore.

Secondly, it might be that the cassette is too worn to work with a new chain. Did you check the amount of wear on the old chain? if wear was between 0.75% and 1%, a cassette swap is probably needed.

atp

Sorted! the front deraileur wasn't paralled with the chain. Cheers, guys!

OLDYELLR

there are special tools to do this, but if you don't want to just throw money at the problem and wait for delivery of the tool, it can be solved with simple hand tools and a bit of ingenuity. You could use a pair of needlenose pliers ground to fit around the chain rollers to squeeze the ling together. If you don't want to do that, use a pair of needlenose visegrips or chanellocks to squeeze the link diagonally.

simplify

I found a really easy way to do this, but it's hard to describe--I'll try to get a picture to illustrate. Basically, you pinch the plates together, and try to move the pins toward each other, until a tiny gap shows behind the pin that's in the elongated plate hole. Insert the blade of a very small screwdriver into that tiny gap behind the pin, twist the screwdriver, and it'll give that pin a shove forward which opens the link immediately with no problem. It's only an issue the first few times you remove the chain. Once you've had the powerlink open a few times, it's really easy and can be done just by hand with no tools and no problem. And in the case of the 9-speed powerlink, they've always been easy right from the start.

Surferbruce

undoing the sram link is always easier with the chain slack. pop it off the chainrings and keep the adjoining links at an angle while you slide the pins of the quiklink towards each other.

erader

removing the link is even simpler with the $12 pliers made by park specifically for the task.

ed rader

simplify

Yes, do take the chain down off the chainring so it's slack, forgot to mention that. And the real beauty of using the tiny screwdriver method is that you can always have a tiny screwdriver with you on the road to help with opening the link that way, whereas a pair of pliers would be very problematic to fit into your seat bag. Not to mention a lot more expensive.

Surferbruce

if i need a tool for a quiklink, whats the point?

simplify

Exactly. And as I said before, you only need the assistance of a tool like the tiny screwdriver for the first few times you open the link. After like 5 times opening it, you won't need any tool. It just slides apart with finger tension. The 9-speed links have always been easy to open without tools, it's just the 8-speed links that are difficult for the first few times. That's been my experience, anyway.

pmseattle

I have never needed any tool to open a SRAM link. I always squeeze the plates on either side of the removable link together with my fingers and the link slides apart.