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PostPosted: Sun Mar 31, 2013 7:54 pm 
retrobike rider / Gold Trader
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What you need to do is get a good quality bolted SRAM cassette and rebuild it with 7 speed spacers


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PostPosted: Sun Mar 31, 2013 8:13 pm 
retrobike rider
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cce wrote:
Spacing will be wrong if you do that.


7 & 8 speed work together don't they?


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PostPosted: Sun Mar 31, 2013 8:28 pm 
retrobike rider / Gold Trader
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Rampage wrote:
cce wrote:
Spacing will be wrong if you do that.


7 & 8 speed work together don't they?



Only by utilising the float in the top jockey wheel. If you cut one sprocket off an 8 speed cassette it'll be slightly narrower than a 7.


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PostPosted: Sun Mar 31, 2013 8:30 pm 
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Shelton brown website has a big section on custom sizing cassettes.


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PostPosted: Sun Mar 31, 2013 10:05 pm 
King of the Skip Monkeys
King of the Skip Monkeys
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And 7spd is 5mm with 8spd 4.8mm - what's 0.2mm between friends?


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PostPosted: Mon Apr 01, 2013 1:06 pm 
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legrandefromage wrote:
And 7spd is 5mm with 8spd 4.8mm - what's 0.2mm between friends?


1.4mm across the block. . . Quite a bit in terms of indexing


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PostPosted: Mon Apr 01, 2013 4:05 pm 
King of the Skip Monkeys
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gtRTSdh wrote:
legrandefromage wrote:
And 7spd is 5mm with 8spd 4.8mm - what's 0.2mm between friends?


1.4mm across the block. . . Quite a bit in terms of indexing


not according to my 8spd/ thumbie combination its not - now rounding about year 5 in its current guise


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PostPosted: Tue Apr 02, 2013 8:45 am 
retrobike rider
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legrandefromage wrote:
gtRTSdh wrote:
legrandefromage wrote:
And 7spd is 5mm with 8spd 4.8mm - what's 0.2mm between friends?


1.4mm across the block. . . Quite a bit in terms of indexing


not according to my 8spd/ thumbie combination its not - now rounding about year 5 in its current guise


1.2mm across the block, you don't count the first cog, only 6 shifts. Thumbies work fine because once you've used the float you also have the inaccurate indexing that help out.
How do ratchet, RF/RF+ based indexing fair, I never did try. Still just run an 8 SPD shifter, the stops will lock it out.


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PostPosted: Tue Apr 02, 2013 10:02 am 
retrobike rider / Gold Trader
retrobike rider / Gold Trader

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I ran 8s road sti on a 7s block for a while. You could get every great but a couple were noisy.


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PostPosted: Tue Apr 02, 2013 10:19 am 
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12 - 28 XTR M900 (Q? type) take out the 13 tooth cog and voila a 7 speed lightweight 12 - 28 cassette with usavel ratios. Admittedly only if your using non compact rings (same for an M950 11 - 30 remove the 11t and you ahve the older 13 - 30 "G" 7 speed cassette ratios.

getting an 11 - 28 XT M737 and removing the 28 would be neigh on impossible as the 24 & 28 T share the same alloy tab they are pinned into. (so it would be remove the 11t cog as per xtr)

after that its SRP Tioga and Goltec TI cassettes or mix and match SRAM as suggested.


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