What size cassette for SS R8000

brokenbanjo Posts: 20
edited April 2019 in Workshop
Evening campers, I’m doing the Fred in a couple of weeks and have a compact 50/34 x 28 setup. Just wondering what sized cassette I can actually use with the SS rear mech. Shimano say 30, but i’ve Seen that for 6800 some people could use 32. Also, will I see a massive difference in pedalling by changing cassettes? 28 is fine for all my other riding, but thinking of making life a touch easier for myself.



  • timothyw
    timothyw Posts: 2,482
    Did you sign up for the Fred Whitton because you wanted an easy ride then?

    Likelihood is that it'll be fine with a 32 cassette - if it isn't you can buy a 105 gs derailleur for about £30 and it'll work with your ultegra shifters and the larger cassette, although you might then be kicking yourself that you didn't get the 34 cassette.

    You can run the numbers through a gear calculator easy enough - you'll certainly notice the difference from a 32, 30 will be more subtle but still a 7.1% easier gear
  • svetty
    svetty Posts: 1,904
    32 should be fine - you might need to adjust the B-screw a touch. Just be careful cross-chaining in big-big if your chain length is marginal.
    FFS! Harden up and grow a pair :D
  • I did the FW on a 50/34 and a 11-32 cassette on a Dura Ace 9000 SS RD. It works, I took the B screw out and screwed it in so the head was against the hangar, but as mentioned above, avoid big-big cross chaining. I tried it two years before on a 50/34 with a 11-28 cassette, but the lower gearing just lets you save your legs enough for the tail end of the event.
  • Cheers fellas. I knew what I was getting in to, but having done all my training on a 28, was wondering about making the day easier for myself. So may just get a 30 and new chain. I got up Hardknott the other week with the 28, but that was only after 40miles, not 90!