New Rear Mech, 9 speed.

Planet X

In the market for a new above.
Looking at SRAM X5, Deore M591 etc.
9 speed, 11-32, Audax bike.
Any other recommendations? Shimano.
Cheers.

smacl

What's up front, AFAIK derailleur capacity is based on maximum tooth difference between front and rear, so if its a triple up front and you're running 11/32 back you need a lot of capacity (e.g. Deore). Compact up front, and AFAIK any medium cage will work.

Planet X

Yeah.....triple.

Must check tooth diff then.

Planet X

So.......it's the difference in teeth between the front chainrings, 48-38-28 which is 20,
and
the difference between the smallest rear cog (11) and largest (32) which is 21..........combined.
41.

This correct?

Planet X

For eg then,

SRAM X7, long cage has a 45 tooth capacity, which seems to fit the bill.
The medium cage of above has a 37 tooth capacity which is out.
Correct?

smacl

Planet X wrote: »

For eg then,

SRAM X7, long cage has a 45 tooth capacity, which seems to fit the bill.
The medium cage of above has a 37 tooth capacity which is out.
Correct?

Looks right, see related question here; http://bicycles.stackexchange.com/questions/7264/how-to-calculate-the-capacity-of-a-rear-derailleur. Road triple I have is campag / FSA mix 52/39/30 front, 30/13 rear, long cage Veloce DR, which works well enough.

Eamonnator

Ensure that your shifters are compatible with Sram X7.
ASAIK some of those Sram rear mechs pull a different length of cable than Shimano ones

CramCycle

As Eamonnator says, what shifters are you using at the moment?

Alek

triple up front and you're running 11/32

I'm running 30/40/50 triple and 11-34 with the longer Sora road derailleur (3500) and no problems...

Planet X

CramCycle wrote: »

As Eamonnator says, what shifters are you using at the moment?

Eh........cheapo Sora I think. Came with bike.
But, most likely I'll be switching to Down Tube shifters on this bike aswell. DA down tube shifters.

I'll probably plumb for XT long cage M771 (I think it is?)

paul a newman

i have a boxed XTR rear mech if you're interested, never used, for E50. Cost a lot more when I bought it new 8 yrs ago

Eamonnator

Dura Ace 9 speed down tube shifters will work fine with an XT long cage M771 rear mech

Planet X

paul a newman wrote: »

i have a boxed XTR rear mech if you're interested, never used, for E50. Cost a lot more when I bought it new 8 yrs ago

What???? Is it 8 years old then???

Eamonnator

Planet X wrote: »

What???? Is it 8 years old then???

Recognise a bargain, when you see it.

Planet X

paul a newman wrote: »

i have a boxed XTR rear mech if you're interested, never used, for E50. Cost a lot more when I bought it new 8 yrs ago

Any pics. or links then Paul?

paul a newman

its in a box in the shed, prob dig it out tomorrow, originally bought it for audax build up with dura ace bar end shifters, but went with an Ultegra set up instead, like I say, It's been in its box for a while now but never been used, will post pics tomorrow

paul a newman

model rd-m900, max cog 32T, its for 8 speed, but I think it works with 9 speed.
i have it boxed, but it has been used, if you're still interested, I'll stick some pictures up later