Chain rubbing on outer ring when in the middle ring...Help!

[wookiee]

Hi

Having spent the best part of today trying to sort this out I am running out of ideas!!! Here is the set up...

- M573 LX chainset
- 107mm bottom bracket
- 7/8 speed Shimano IG chain
- 8 speed rear cassette
- Bike = 1995 Orange P7

The problem is the chain is hitting the little pins on the outer ring when its in the middle ring. I've checked that the BB is the right width and according to Sheldon Brown this is correct. The chain is brand new the rear cassette in good condtition. The chainset has worn teeth (and was catching the pins on the outer ring) Thought that new rings might help so fitted those and no good either the same catching problem.

To try to eliminate the chain being the problem so I fitted a 10 speed chain which is narrower and still it caught on the pins!! Its like the middle and outer ring are too close together should there be any spacers in there?

I am at my wits end!!! Anyone else had this problem? Is this to do with them being compact 94BCD rings?

HELP!!!

Doug

 

[wookiee]

Re: Chain rubbing on outer ring when in the middle ring...He

I have even tried to unscrew the drive side and screw in the non drive side of the BB by around 5mm to see if the extra on the drive side would stop the chain catching...but it didn't! :evil:

 

[Raging_Bulls]

Re: Chain rubbing on outer ring when in the middle ring...He

A picture says more than a thousand words.

 

[Woz]

Re: Chain rubbing on outer ring when in the middle ring...He

Sounds like you need some spacers on the outer ring, or just file off or knock out the pins and be done with it.

 

[The History Man]

Re: Chain rubbing on outer ring when in the middle ring...He

Had similar on a toad bike with new ring. Cut and drilled spacers Out of aluminium ducting. Simples.

 

[marc two tone]

Re: Chain rubbing on outer ring when in the middle ring...He

Is it the original middle ring? As some alloy aftermarket ones can be chunky.

I have the same chainset in the shed but too dark to get in and see how it's put together.
I reckon the middle needs shoving over towards the granny ring, rather than the outer getting pushed further out. Any ring spacers with shimano chainsets are usually at the back of the middle ring.

 

[wookiee]

Re: Chain rubbing on outer ring when in the middle ring...He

Thanks for the replies...

Marc - yes it was doing it with the original stock rings (that were worn and the middle slipping). The new ones are original Shimano rings 94 bcd etc so Hmmm...

THM - yeah spacers were looking like the only remaining thing to do, but don't want to move the middle ring too close to the granny...

Woz - Better to bring put spacers on the outer then? Don't really want to file the pins as they "help" with the shifting? lol

Bulls - I'll get a pic up

 

[mattr]

Re: Chain rubbing on outer ring when in the middle ring...He

What gear at the back?
Middle ring/Smallest sprocket can sometimes catch.
If it's more than that, you might have the ring on back to front, some have an offset.
Or, as mentioned, some spacers missing.

 

[wookiee]

Re: Chain rubbing on outer ring when in the middle ring...He

What gear at the back?
Middle ring/Smallest sprocket can sometimes catch.
If it's more than that, you might have the ring on back to front, some have an offset.
Or, as mentioned, some spacers missing.

In the bottom 3 at the back but to the point where it is lifting the chain off the teeth at the front...Ring is defo on the right way round....spacers looking like my option...

 

[wookiee]

Re: Chain rubbing on outer ring when in the middle ring...He

THM...your going to have to explain this one to me alu ducting? How thick was it? Would beer can washers be an option?