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7 speed DX Thumb shifters!!

inbred-jonathaninbred-jonathan Posts: 9
edited March 2009 in Workshop
Hi, am sure a 1000 people have asked this before but, can I use 7 speed thumbies with an 8 speed cassette? also is a scram x9 rear mech going to work with these or do I need to replace that as well?

Thanks jonathan

Posts

  • whyamiherewhyamihere Posts: 7,519
    1. You can use 7 speed shifters on an 8 speed cassette, but obviously you'll only have 7 gears.
    2. You will need to replace the X9 with a Shimano mech.
  • Cheers buddy, some one told me that my old dx 7s can be pushed past the final index effectivly giving you the 8th gear, ever tried this?
  • redveeredvee Posts: 11,921
    There was many a rumour about this working with 7sp thumbies many moons ago, mainly with XT thumbies not DX.
    I've added a signature to prove it is still possible.
  • whyamiherewhyamihere Posts: 7,519
    No, I've never tried that. It might work I suppose, but I can't see it, because when you're past the final indexing click the shifter can normally move a bit further (this is common with many shifters) but there's nothing to hold the cable in place, and the spring tension will pull it back. I suppose you could simply ride with your thumb on the shifter holding it in place if you really want to use the 8th gear, but I don't think it would work otherwise.
  • thanks guys, gives me a few options. have just fixed my x7 shifter (luck!) so may go for a scram front mech and keep the extra gears, pity as i was looking forward to breaking out the thumbies again!
  • My XT 7-speed thumbies did not index with my 8-speed Shimano cassette ... almost, but not quite!
    AT MY AGE, I SHOULD KNOW BETTER !!!
  • balthazarbalthazar Posts: 1,565
    My DX 7 speed shifters definitely had the 8th click. I used them with a Sachs freewheel (on Mavic hubs, built with - drum roll - twisted spokes...).
  • I also had "radical' spokes! I have to admit that they were super strong and the front is still going round and round, 12 years later, on a bike I made for my mum.
  • It can be done. I once ran DX thumbies with a 105 rear mech and an eight-speed 11-32 cassette! If you have any issues you can always run the thumbies in friction mode. Hey that's what we all did before indexing was invented...
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