Originally Posted by
Vexxer
I currently have a 105 11sp 11-28 cassette, with a Ultegra rear derailleur. Its what came on my Fuji. I would like to upgrade the cassette to a 11-32 Ultegra. What size derailleur and chain would I need with that?
Originally Posted by
dksix
I just went from 11-28 to 12-32 and my 105 5700 SS works find. It's only rated for 28 but a member here said that he had had them work up to 32 and suggested I try mine. I'm glad I did because with a few turns of the adjustment screw it shifts from top to bottom with no issues. I don't know that the 11 speed will work but if you have th cassette I'd say it's worth a try. I didn't have to replace my chain, it was long enough to work big to big but I replaced it with a 1 link longer.
I went from 11-28 to 12-30 on a 5700 short cage derailleur. Obviously, there's a tad more needed with a 32t but with the B screw all the way in, it allows for more distance between the upper jockey wheel and the cassette teeth.
Someone on another forum gave me some great advice when I was looking at going 32t:
"Your RD will work with a 30 but the 32t will be challenging. Even with full use of B screw the issue is the clearance between the top jockey wheel and the bottom of the large sprocket.
The diameter of a 28t sprocket is 113mm. The diameter of a 30t is 121mm - basically 2mm additional radius per tooth Measure what you have now and do the sums: is there 8mm spare space there ie to get a 32t in?
So, I guess the OP should measure the distance he has between the jockey wheel and cassette teeth and see if he has the required distance with the B screw all the way in. I have more than 8mm gap, so could probably get a 32t in there, I opted for a 30t in the end as I got a good deal on an Ultegra 12-30.
