New Shimano Rear Derailleur help

ventana · 2 Weeks Ago

Hey, does anyone know what they changed between the newest shimano ultegra rear derailleur 6700 and the 2008 and earlier model the 6600?? They claim that to use the new shimano wider range cassette, 11-28, that you must upgrade to their newer rear derailleur.

I am planning to upgrade my interloc racing design 12-28 to an 11-28 and run that on my shimano compact crank set. I plan to use the old shimano derailleur I already have. Anyone know what is up with this new 'compatability' requirement from shimano.

Any help or feedback is greatly appreciated.
thanks

**Dave Hickey** · 2 Weeks Ago

I've run 28t cassettes on 6600 RD with no problem....

Shimano is famous for telling you that something won't work without the newest model.

In reality, it's usually not the case...

ventana · 2 Weeks Ago

yea, thanks for that. Indeed, I hear ya, and hope this is the case... I believe it is the case, just wondering if others had a bit more info.

Also, have you ran as low as an 11 tooth? Shimano only makes a 12-28 but IRD makes an 11-28 and that is the one I plan to get.

yea, like the latest new ultegra chain 6700 from Shimano is direction sensitive!!
Pretty ridiculous. And the verbage they put in the specs to tell you the right direction have been converted from Japanese so poorly that it is hard to understand. I just wonder how many folks will put the chain on 'backwards' and never realize it... regardless of the fact that it probably does not matter.

thanks for your input

brblue · 2 Weeks Ago

Actually, it makes some sense to have the left side of the chain links (their inner part) shaped to optimize upshifts, while the right side of the links (their outer part) is more strong and less / differently ramped.. or something.

I think you'll be fine though using a 6600 RD and a 28 T large sprocket

If you're going with a 11-28 cassette though, make sure your chain is long enough, so the RD doesn't touch the large sprocket in small ring / large sprocket combination..
(with a compact crank for instance and large range cassette, there'll be a chance to overshorten the chain, if the small-small method is used..)
Though I think that must be cared for, with any type of short cage derailler...

DaveT · 2 Weeks Ago

I've run an IRD 11-30 cassette with both a 7800 and 6700 standard rear derailleur. In each cases shifting was very good. No *need* to convert to a 6700 derailleur just to run a 28 tooth cassette. Pay attention to the chain length and B screw tension and you'll be O.K.

ventana · 2 Weeks Ago

The 11-28 cassette showed up last night and is installed and seems to shift fine while on the bike stand. The 6600 rear derailleur seems to be doing just fine. Was not able to take it outside and ride which is the true test because it was dark and raining. I will post the results once I have ridden. Thanks for everyones input.