Suitable derailleur for my upgraded old touring bike?

Michael Falk
Michael Falk Posts: 169
edited February 2010 in Tour & expedition
My old 21 sp, steel touring bike is being upgraded to a 27 sp. I've been told my old (but still running well) Suntour derailleur will not cope, especially with the small 12 or 11 tooth cog. Seeing it's on special, I'm considering buying SRAM X.9 OE Rear Derailleur 2009 long cage; should it run OK? In the past I used 7 sp 13-32 (with 46-34-24, perfect touring gears for me). Should the SRAM have no problems with 12-32 or, even better, 12-34? I'm using downtube friction shifting which I think should not be a problem, or is it?

There's no way I can find screw on freehubs with a wide range of gears now & I like this bike. So, I'm now having to go 27 speed with it. I would've put this in a mechanics forum but they don't appear to have a "touring" approach.

Comments

  • RedJohn
    RedJohn Posts: 272
    I'd've thought you could track down screw on freewheels.
    I've got a 7-sp one somewhere that I bought for a conversion that didn't happen. Not touring ratios but still obtainable. I think I got it through ebay.

    But if you're using downtube friction shifters, any mech should do. Including the one you have right now, I'd've thought - why would it not work?
  • RedJohn
    RedJohn Posts: 272
    http://www.sjscycles.co.uk/category-Fre ... eed-79.htm
  • andymiller
    andymiller Posts: 2,856
    I can't remember the details. but IIRC the SRAM X series derailleurs all work with a shorter cable pull than Shimano shifters. But as you say you're using friction shifters so I'd have thought you'd be OK. On the other hand, I've been impressed with the quality of the Shimano Shadow rear mechs.
    Italy Cycling Guide
  • Michael Falk
    Michael Falk Posts: 169
    Thanks for the replies.

    The examples at SJSC are the screw on freewheels I can get. A 28 large cog is a gear too low. Also, I've used such a 14-28 freewheel for commuting. Very poor quality, its life was very short. The mega-range freewheel I do not like either. The jump between 1st & 2nd gears is, I think, ridiculous. Shimano only made them for their lowest levels of components.

    I thought that friction shifting would not be a problem, I just wanted to seek other peoples' opinions to make sure.
    That my old Suntour derailleur will not cope is something that I was told by a mechanic. He said changing to the small cog might be a difficulty. I also had the problem before on another bike. I put on a 14-32 cluster (replacing the 13-30) & the old ('92) XT derailleur couldn't cope very well with the large cog. I bought a new XT & it copes very well.
  • blackhands
    blackhands Posts: 950
    One of the problems with using 7 speed screw-on blocks is the position of the bearings in the hub. Fitting a 7 speed block puts the hub bearing well inside so tha there is more strain on the axle than it was originally designed for. Axle failure is common and I have had problems even with Campagnolo record hubs. It was because of this problem that cassette hubs were developed - putting the bearings nearer to the outside.

    For a touring bike it is essential for it to be reliable so I would advise either 9 speed conventional hubs or 9 speed 135 oln ATB hubs such as Shimano XT.

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