New rear mech

bikeit65

I am looking for a Shimano Ultegra 9 speed long rear mech, anyone here know where i could get one, tried Google and a few local bike shops, no joy :?

dru

do you need to get a 9 speed specific one - won't a 10 speed one work - isn't it more to do with how many moves the STI can produce on the mech itself?

freezing77

Bikeit65 wrote:

I am looking for a Shimano Ultegra 9 speed long rear mech, anyone here know where i could get one, tried Google and a few local bike shops, no joy :?

To paraphrase the late great Sheldon Brown, mechs are dumb, shifters are intelligent.
Derailleurs do what the shifters tell them to, they don't know if they are 9 or 10 speed

bikeit65

Dru im not too sure, if a 10 speed one will work that will make it a lot easier, too be honest im not sure if the rear mech is done only going on the advise of a guy at a LBS.

yaya

There are some 6600 rear mechs on eBay. I had one on an old-ish bike running 9 speed. I believe the 6700 works the same way

bikeit65

I now know i need a long cage mech, there only seems to be medium or short cages.

jameses

Unless you're running a mtb cassette with a triple, a medium cage mech should be fine.

bikeit65

JamesEs i am not doubting you but are you sure it will be suitable as the mechanic at the LBS said that only a long cage will do.

jameses

Rear road derailleurs generally only come in SS (short cage) or GS (medium cage), but GS is sometimes referred to as long cage. There are actual long cage mtb mechs, which you would only need if you're running a mtb-style setup - triple chainset and wide range cassette at the back.
You can work out if your setup will work if you have a look at the tech docs for a rear derailleur, like this:
http://techdocs.shimano.com/media/techd ... 702204.PDF
The GS has a maximum capacity of 39T, the capacity being: (no. of teeth on largest chainring - no. on smallest chainring)+(no. of teeth on largest sprocket - no. on smallest sprocket)

So even with a 52/39/30 chainset and 11-28 cassette, you have (52-30)+(28-11)= 39; you're still okay with a GS mech.

Hope that helps!

bikeit65

JamesEs thats great, my set up is triple at the front 52/42/32 the rear is 9 speed 12/25. so do you think the GS mech would do.

jameses

That will work fine - I'm running almost the same setup (52/42/30 and 12-23) with a gs mech with no problems 8)