Old 5 speed, convert to 7 speed

adwt2004
adwt2004 Posts: 93
edited January 2012 in Workshop
Hi,

I might be getting an old racer which is a 5 speed and has a rear drop out of 126mm. Can you this be changed to a 7 speed? I'm presuming it is a thread on freewheel cassette and plan on getting new wheels with a modern hub and cassette type.

Is this kind of thing possible?

Comments

  • ugo.santalucia
    ugo.santalucia Posts: 28,274
    You can go 7 speed, but only with an old freewheel, keeping the same hub. Are you sure it's 126 mm? 5 speed were usually 120 mm. Some frames even with 126 mm dropouts will not take 7 speed, but only 6.
    If you want a modern setup with freehub and cassette, then you need to cold set the rear dropouts to 130 mm, realign dropouts and mech hanger and then you can fit any drivetrain you like. This can only be done with steel frames, if it's alloy, forget about it...
    It's not difficult, but it takes some tools and a bit of experience (or a willing bike shop, doubt Halfords or Evans will do that for you). If you live in my neck of the woods, send me a PM and maybe I can help you
    left the forum March 2023
  • adwt2004
    adwt2004 Posts: 93
    My desire to change to a 7 speed is mainly because I'll need to change the cassette on the bike and possibly the wheels and I would go modern with the hubs etc (cassette fits on splines) and I wanted indexed shifting and I'm struggling to see anywhere where you can buy 5 speed downtube shifters now. Other than that, 5 speed would be fine.
  • ugo.santalucia
    ugo.santalucia Posts: 28,274
    Well, it's a bit more complicated than you think... and frankly not worth it... 7 speed is jurassic anyway and there is no indexed system for road bike on the market which takes 7 speed... even 8 is an oddity these days and 9 is getting decommissioned... I'd rather stick to an old system with an old bike... parts can be sourced without too much trouble on Ebay. A 5 speed freewheel will cost you around 25 pounds as new old stock...

    Ask Nigel at campyoldy for parts
    left the forum March 2023

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