Upgrading Simano sora gearing

Advocar Posts: 5
edited June 2008 in Road beginners
:D Hi I am new to biking and have Avanti Monza bike Shimano Sore components.
Front 50/39. Rear 8 cassette 12/25. I ilve up a hill and currently able to bike up in lowest gear for approx 350m. Total 2Km but steeper section as well. I have improved but still a long way to go. Dont use clipons as yet as need to walk to recover. My lowest gearing has 1.56 ratio. Have borrowed a triple geared 27 speed with 48/38/28 12/34. Lowest has 0.82 ratio and can push #3 at 1.4 for longer time. I have STI 8 shifters and double on the front/crankset. Front set cannot accept 3rd 30T ring, no inner mountings. If I was to change to say a Sihamno 105 series 9 cassette CS-HG70 11/34 or a 10 cassette, with 105 STI changers and narrow chain could I still use my existing 50/39 crankset. The 34T would give me a 1.15 ratio with 34T and 1.22 at 32T.
I would like to be able to sit down for some of the hillclimb.


  • acorn_user
    acorn_user Posts: 1,137
    You could do what you wanted with a new 8 speed cassette. If your largest rear cog is above 27-30t or so, you probably ought to buy an mtb rear mech. Shimano Deore and Alivio models would do the job well.
  • ddraver
    ddraver Posts: 26,391
    Do it quick cos Shimano have just raised their prices with immediate effect!!!

    oil price and stuff...
    We're in danger of confusing passion with incompetence
    - @ddraver
  • Advocar
    Advocar Posts: 5
    Thanks to both of you. Will have to get orgainised ASAP :roll: