Cassette Advice please

mr_eddy Posts: 830
edited July 2015 in Workshop
I am planning on doing a mini long weekend tour of the Peak District on my vintage Dawes Windsor. I have converted it to a single chainring up front as the 52t ring was bent so its just using a 42t up front. I have left the front mech in place as a impromptu chain keeping device to avoid chain drops.

This obviously only leaves me with a 1 x 6 setup which is fine for most situations but I am thinking that the 14-28t cassette is not going to give a low enough gear for some of the big hills in the Peaks, My question is if I switch to a Shimano MF-TZ20 14-34t do I need to get a new rear mech or a new chain ? The 14-34t has normal gear gaps but then the last gear jumps up to 34t. The full ratio of the 14-34t is 14/16/18/21/24/34

I am just concerned that the very old (but perfectly functioning rear mech) might struggle making the big jump from 24-34t ? The chain is fairly new and only covered 300 miles so I know that is good and it was setup for a double up front (originally a 12 speed bike) so I am thinking it should be long enough.

Hopefully someone can confirm that the 14-34t will be fine and I can crack on with getting the pannier's ready for next weekend.

Advice please ?


  • nicklouse
    nicklouse Posts: 50,675
    ok first things first.

    it is not a cassette it is a freewheel.

    when you went to 42 on the front did you change the chain length? if yes then you will need a new chain.

    as to the rear mech it depends on what it is.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mr_eddy
    mr_eddy Posts: 830
    Thanks for response although I should point out that the wheels are new and as such they do use cassette's and not screw on freewheels. The 42t chainset is the same as the original double 42/52 so I did not change the chain length