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 Post subject: Race Face crank issue
PostPosted: Sun Jul 07, 2013 7:47 pm 
P.o.T.M. Winner / MacRetro Rider
P.o.T.M. Winner / MacRetro Rider
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Location: In the foothills of the foothills of The Cairngorm Massif :D
Evenin :D

Today I swapped rings from a 5 bolt Suntour crank arm to a Race Face Turbine. Unfortunately, whilst the outer and middle rings are fine, the granny sits too close to the middle ring due to profile of the crank, where the chainring bolts fit.
The Suntour crank has a flange profile which places the granny ring closer to BB, but the Race Face crank is different, although the bolt hole diameters are identical. Do I need some spacers or do I need different rings?


Last edited by Mr Panda on Sun Jul 07, 2013 8:15 pm, edited 1 time in total.

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PostPosted: Sun Jul 07, 2013 8:11 pm 
Old School Grand Master
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Location: Behind you with the duct tape pulled out.
Sure i have heard mention of spacers being used on rf cranks.


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PostPosted: Sun Jul 07, 2013 9:14 pm 
BoTM Winner / Gold Trader
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16mm bolts + 9mm spacers on Turbine LPs. IIRC the standard Turbines are the same.


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PostPosted: Sun Jul 07, 2013 9:26 pm 
retrobike rider
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Steel Granny ?

You need 1mm longer spacers for steel granny rings (might not be for all sizes) compared to the alu rings the Tubines will be designed for.

or you need to turn the granny around.
Original design was spacers into the holes (probably the suntor), later it switched around to recess the bolt (probably the turbines).

P.S. IB or LP ?


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PostPosted: Sun Jul 07, 2013 11:52 pm 
P.o.T.M. Winner / MacRetro Rider
P.o.T.M. Winner / MacRetro Rider
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Location: In the foothills of the foothills of The Cairngorm Massif :D
It's a stainless steel Specialized granny - came with the original Suntour stuff on my 1992 Cinder Cone and everything worked fine.

FMJ - yes it looks as if spacers and longer bolts of approx those dimensions would do the trick. I'm just not sure if there is a part missing on the RF's, or if I need to use a specific granny with them :|

I'll try get a photo up to explain better.


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PostPosted: Mon Jul 08, 2013 8:07 am 
retrobike rider
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Photo's will help. I actually think the spacers are 8.30mm
I didn't think you didn't have any spacers at all :oops:

I'm assuming it's it's a 110/74.


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PostPosted: Mon Jul 08, 2013 5:41 pm 
P.o.T.M. Winner / MacRetro Rider
P.o.T.M. Winner / MacRetro Rider
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Location: In the foothills of the foothills of The Cairngorm Massif :D
Piccys:

the cranks in question (sorry not sure which version of turbines)
Image

outer and middle rings look ok, but granny is squashed up against inner face of middle ring
Image

Image

granny bolts straight onto inner face of spider - I think this is where there should be spacer(s) or similar.......
Image

Suntour on the right has raised flanges on arms into which granny ring bolts go. RF doesn't.
Image

Image

Suntour.....All my other cranks appear to be similar in design to this
Image

Advice appreciated :D


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PostPosted: Mon Jul 08, 2013 6:19 pm 
BoTM Winner / Gold Trader
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You need the longer 16mm bolts and the 8.3mm spacers (the 9mm I originally posted was measured w verniers on an assembled crank, and was approximate). On Shmoo/ST cranks the granny is already spaced out correctly via the raised mounting bosses.


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PostPosted: Mon Jul 08, 2013 6:56 pm 
retrobike rider
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8.30mm is from their early instructions.
M900 XTR also used the loose spacer setup as did a few others.
No idea why Shimano used it for some, guess it saved on cold forging (they would add extra width ?)
For others it was do to the spider setup.


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PostPosted: Mon Jul 08, 2013 10:29 pm 
P.o.T.M. Winner / MacRetro Rider
P.o.T.M. Winner / MacRetro Rider
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Location: In the foothills of the foothills of The Cairngorm Massif :D
Excellent guys, thanks - as I suspected

Now, where to buy spacers and long bolts?

:xmas-big-grin:


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