Cassette compatibility

[Cataboo]

I'm running an SRAM 11-28 on my old ultegra 10 speed rear derailleur no problems.

[nscrbug]

Hmmm...interesting. But I think this compatibility issue is limited to the Ultegra 6700 11-28t cassette. I'm sure if I bought an 11-28t 6600, there would be no issues. But I figured, with the 6700 offered at a such a great price ($59 at Nashbar)...I would just go with that. So I guess my specific question is...is anyone running a 6700 11-28t cassette with a 6600 RD?

[redrhodie]

Hmmm...interesting. But I think this compatibility issue is limited to the Ultegra 6700 11-28t cassette. I'm sure if I bought an 11-28t 6600, there would be no issues. But I figured, with the 6700 offered at a such a great price ($59 at Nashbar)...I would just go with that. So I guess my specific question is...is anyone running a 6700 11-28t cassette with a 6600 RD?

I just got the 11-28T 6700 cassette a couple of weeks ago, and I'm using it with an Ultegra long cage derailleur from 2007 (not sure if it's 6600, though--can't find a model # on it, but it's definitely not a 6700). It works just fine. I've done a few hilly rides, and haven't had to have it adjusted yet.

[nscrbug]

I just got the 11-28T 6700 cassette a couple of weeks ago, and I'm using it with an Ultegra long cage derailleur from 2007 (not sure if it's 6600, though--can't find a model # on it, but it's definitely not a 6700). It works just fine. I've done a few hilly rides, and haven't had to have it adjusted yet.

Well...this is good news to hear! And I just realized that in my last post, I stated that I could just buy an 11-28t 6600 cassette - ummm, no such animal exists, so my apologies for incorrectly stating that. Looks like I will have to investigate this matter a bit further.

I'm fairly certain that I need a different RD in order to get this to work...because based on what I've been told by 2 different LBS's, my stock Ultegra SL 6600 rear derailleur does not have enough range to accommodate a 28 tooth (or even a 27 tooth) cog...I was told that I am "maxed out" on my RD with my current 12-25 cassette. And since I definitely need a new cassette (mine is worn - new chain is skipping)...I need to figure out what to do ASAP.

[DebW]

Is your crankset double or triple, and how many teeth in each ring? A RD has a maximum cassette cog it can handle as well as a maximum tooth difference (add differences in cassette large-small and chainring large-small). Tooth difference defines the amount of chain that the RD can wrap up.

[nscrbug]

Is your crankset double or triple, and how many teeth in each ring? A RD has a maximum cassette cog it can handle as well as a maximum tooth difference (add differences in cassette large-small and chainring large-small). Tooth difference defines the amount of chain that the RD can wrap up.

It's a compact 50/34. Yes, I was basically told the same thing by a LBS...that my current 6600 SL RD is maxed out with my current 12-25 cassette...so it would not be able to accommodate a 27t or 28t cog. However...when I do the formula you provided above, I get a maximum difference of 29...so now I'm confused...

[aicabsolut]

The Ultegra RD will probably work. A Dura-Ace 7800 RD will not work well with the 11-28 spread, but for some reason the 105 and ultegra ss RD are a bit more friendly to larger gear spreads with a compact. However, your chain might be a bit short now...

[lo123]

It's a compact 50/34. Yes, I was basically told the same thing by a LBS...that my current 6600 SL RD is maxed out with my current 12-25 cassette...so it would not be able to accommodate a 27t or 28t cog. However...when I do the formula you provided above, I get a maximum difference of 29...so now I'm confused...

My LBS said it'll work and that's Ultegra 6600 SL with compact crankset. And it does work. Actually, LBS owner, a female(!), has the same setup on her Madone 6.2

Like I said, it does need more frequent tuning, but I'm learning how to do that myself and hubby does it for me now, so I don't have to go to the LBS.