I currently have 5700 shifters/FD/RD along with a 4600 cassette (12/28), and would like to 6700 cassette (11/28). I was looking at the PB product page for the 6700 cassette, and it says "11-28T size requires use of the Shimano Ultegra RD-6700 Rear Derailleur or Shimano Dura-Ace RD-7900 Rear Derailleur." Anyone know if I can use my 5700 RD despite what the PB site says? I'm curious bc there is also a 5700 cassette in 11/28 that's available as well.

Should be ok.

Ignore PBK. It'll work just fine

/ thread

Yep. It'll work just fine.

Why, though? It's not going to shift noticeably better. I've got everything from 4600 to Dura Ace cassettes, and I don't notice any shifting difference between them.

Weight? Get a 105 cassette and scarf up an excess alloy Ultegra lockring to make up the 1.5g of weight difference between a 105 and and Ultegra cassette.

Do you really need the 11 instead of a 12? What cog do you give up? (I'm too lazy to look.)

If you need a replacement, just stick with 4600. I've got several that I use in races - an 11-25 is a great one to have for some races.

If you want to improve your rear shifting, find a Dura Ace 7800 RD cheap somewhere. Works great with 5700 shifters.

I'm currently running a 6700 cassette with a 5700 derailleur, no problems.

Thanks for the replies, all!

Well, I figured since I upgraded the stock wheelset to Reynolds Solitude, I might as well replace the cassette for something lighter.


Claimed weights:
4600-- 293g (12/28T)
5700-- 250g (12/25T)
6700-- 208g (11/23T)

I guess when spec-ing the gearing more similarly, we get that 1.5g difference instead of the big spread published above?

Yes, those weights are misleading because of the size differences. Stick with the Tiagra cassette and put your $ in nicer tires.

I have a 5700 RD and ran a 6700 11-28 all last season...zero issues. I picked up 12-30 on the cheap this winter and it even works fine.

On a side note...if you drop $80 on a 6700 cassette at this point, you're getting taken for a ride. Look around, with the 6800 in full steam those are on clearance all over the place.

$53 (11-28 or 12-30):
Shimano Ultegra 6700 10 Speed Road Cassette | Chain Reaction Cycles

May I suggest you look at the 12-30? I know I use 36-30 full granny for climbing more than I use 52-11 for full on balls to the wall speed runs (and I'm too mortal to run flat with 52-11)...

Just food for thought...

Yep. About the only difference I can see between Ultegra and 105 10-speed cassettes other than the color is the 105 uses a steel lockring while the Ultegra uses a lighter alloy one.

Okay, thanks!

search out a SRAM PG-1050 on e-bay.. ~$60, take your pick of gearing.

I have a 9-speed version (11-26) and it works nicely with my Shimano 105 (5500 era) stuff. No idea what the weight issues surrounding it all might be, of course, as I don't worry too much about minor weight differences, personally.

I have a 5700 rd and 6700 11/28 cassette and it works perfectly!

Well, no biggie about price; I have about $88 in Performance points, so it was "free." LOL I got the 6700 (11/28), and it works fine with the 5700 RD .