New granny on STX - spacers?

[rbike]

Got a 20 teeth granny and want to put it on a STX crankset. However new granny is flat and granny on the STX is bent (pressed bent). Pictures attached. What screws and spacers do I need, to fix granny in place? Anyone done that already? Would this work or it would breake down?
A shortcut to a solution would be just OK.

 

[hamster]

Hmm, you are out of luck. For one year Shimano (the kings of planned obsolescence) made STX chainsets with 95mm PCD instead of 94mm. At the same time they fixed the granny ring to the inner.

It's really irritating. Replacement rings are as rare as chicken teeth and the inner as far as I know cannot be separated from the middle - IIRC it's welded or riveted.

 

[taffy]

Nearly Hamster
Alivio was a one piece riveted job

STX had the inner bolt on using the middle ring as a spacer - so it held the middle ring. then the outer ring was bolted to the middle. Effectively the granny ring does all the holding.

You couod used spacers but as the holes are the wrong pitch it wouldnt work
PACE made an adapter to go on which mean you could just put normal rings on - they pop up from time to time.

But its nailed right above - planned obsolescence and incompatibility form the word go!

 

[hamster]

Thanks for clearing that one up, Taffy. It's years ago that I came across one, concluded it was too weird to keep and got shot of it asap!

 

[taffy]

Thanks for clearing that one up, Taffy. It's years ago that I came across one, concluded it was too weird to keep and got shot of it asap!

I only know as i had the Pace adapter myself and listed it on ebay so had to find out myself! ><

 

[rbike]

Thanks for the answers.

I could drill 5 new holes, since there is enough place. If only 1mm is in question, then chainring offers enough edge to do it. It is also quite heavy, so I think is made of steel - so another hole would not damage it.
Then I would only need spacers. I could cut out of an alu or steel tube...anyone done that?

 

[hamster]

To be honest, you can probably get a used LX crank for around £10-20. I'd quit and fit that instead and not throw good money after bad.

I've even got an M563 175mm right hand crank and a 42T ring you are welcome to for the postage.

 

[rbike]

pm'd you, hamster