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  1. #1
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    My downtube to STI conversion plan (Am I nutso? You be the judge!)

    I've spent the last few weeks reading everything I could on the web about downtube to STI conversions. There's a lot out there, and I've learned that you always have to be aware of WHEN something was written since things change over time in the real world but writing on the web is usually frozen in time. It all seems to come down to how bad you want to do it and how much money you want to spend.

    Anyway, the bike is an early 90s steelie road bike with with full 105 groupset (7 speed cassette freehub) and 130 rear spacing. Front and rear derailleurs are indexed. I spend almost all my time on the hoods and this is a 100% commuting bike, so the ergonomics are worth it and I'm not bothered by the some of the drawbacks that the odd racer posts here and there. I am however unwilling to spend more than a couple of hundred bucks, since I'm not in LOVE with the bike and could just as easily sell it and buy something newer.

    Anyway, as I've researched and watched the potential cost and complexity rise, I've made a few mental trade-offs and compromises. I'd like to do the conversion, but I also want it to be cheap and I want to do the work myself. I wonder if you more experienced bike techs might take a look at my thinking and poke holes in it?

    [I knew beforehand that I didn't want some of the other solutions like barcons or the Kelley TakeOff: I'm definitely an on-the-hoods guy, so those options don't offer much more than what I have with downtube shifters already.]

    OPTION 1: A full Shimano conversion with new 105 parts, but I nixed this pretty quick since I would need to buy the levers (costlier than older NOS stuff) and also change the freehub, get the wheel redished etc. Way too expensive and I couldn't do the work all by myself.

    OPTION 2: A Shimergo (Shimano + Camagnolo Ergo) setup, which offers the benefit of Campy's internal cable routing. I didn't mind mixing and matching components between both vendors, but things get complicated quickly with differences in gear ratios, cable pull lengths etc. I also would need a new derailleur and chain, and could never figure out if there were other possible drivetrain changes. I realized it was getting expensive and that I probably couldn't do the work myself. So I nixed that idea, and sadly reconciled myself to the likelihood of a new set of wires messing with the clean lines of my lovely quill stem and vintage handlebars. Oh well.

    OPTION 3: Put on some 8-speed Shimano SORA brifters. From what I can tell, this would be 100% compatible with my early 90s 105 mech and would let me keep my freehub and wheel because I can use the limit screw on the rear derailleur to make it like there's no 8th gear. I won't love the pokey new cables, but what can you do... Makes sense?

    OPTION 4: The last current best option is to put on some 7-speed Shimano RSX brifters. It looks like they will work fine with my 7 speed set-up and there's no need for a new wheel. Also no need to fine tune the rear limit screw to fake out the 8th gear built into the shifter. I've looked into the technical side and I feel pretty comfortable making the swap myself since I've built up a frame before and I went ok.

    So the RSX option is the one I am looking to go with. The brifters are a bit tricky to track down but they are out there and still way cheaper than a new 105 or Campy set. Am I missing something obvious here?

    Thanks for reading and helping out. I'll post before and after pics once it's done. I've been inspired to do this by discovering this forum and reading through the Mechanics and C&V threads for a couple of months.

  2. #2
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    Option 3. Sora are easy to find, way cheaper than 105 and up and since you ride the hoods all the time they should function fine. The alternate cable routing trick and limit adjustment should work just fine then upgrade to 8 speed freehub at your leisure.

  3. #3
    Senior Member BCRider's Avatar
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    I've used 8 speed shifters on 7 speed cassetes and while it can be tuned up to work it's not the ideal setup. But if you want to go that way then when tuning it set it so it drops to the smaller cogs reliably and live with having to slightly overshift the lever when pulling to the bigger cogs. You'll only need to do this slight overshifting for the last couple of bigger cogs where the very slight 7 to 8 speed difference shows up. Or if you're lucky it may not even show up. It's a very close thing.

    Other than that it sounds like you're firmly after only brifters as an option. Given that I think your idea of shopping for a good price on a basic set or finding an older RSX set is a good plan compared to what would be a more costly front and rear combo upgrade. But some patience for this will likely be required since as you mention that stuff doesn't show up ever day.
    Model airplanes are cool too!.....

  4. #4
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    Sounds like you have it under control... there's a pair of rough but serviceable RSX shifters on EBAY right now, and Sora 8-speed come up every now and again. The Sora 8-speed won't work quite as well, tho., since the cable pull will be slightly too low for the cassette- it will need to adjusted carefully and often.

  5. #5
    Senior Member canyoneagle's Avatar
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    If you really spend all the time on your hoods, why not go with a handlebar that offers this position (bullhorns, others) and install a bar-end shifter. Cheaper, simpler.
    Currently one bike: Singular Gryphon do-it all bike with Nuvinci N360
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  6. #6
    Senior Member sonatageek's Avatar
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    I picked up a set of NOS 7 speed Sora STI from an ebay store (part of a bricks and mortar bike shop) for about $80 shipped a few months back. They had multiples listed, so that could be worth a search. I can't check ebay from here to see if they are still selling them.

  7. #7
    coprolite fietsbob's Avatar
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    :
    Last edited by fietsbob; 08-12-10 at 03:06 PM.

  8. #8
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    New microshift 9 or 10 speed brifters can be had new for 100-130 bucks, the money you save vs 105 brifters will pay for the new wheel you will need

  9. #9
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    Quote Originally Posted by fietsbob View Post
    Kelly takeoffs will let you put friction downtube levers up by your thumbs, when on the brake hoods , that is simpler and skips all the fussy synchronization required to makes STI stuff klick in.
    +1. This post saved me a lot of typing. I'm an on-the-hoods guy too and the Kelly Take-Offs allow me to ride that way just like brifters do.

  10. #10
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    Thanks folks! Keep any feedback coming. Regarding barcons and the Kelley TakeOff, I've looked into those but they're just not what I'm looking for. My favorite riding position is on the hoods on standard (non-ergo) old-school handlebars. Dunno why, but I just like it.

  11. #11
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    It depends on how attached you are to that bike. If your rear spacing is 130, why not pick up a wheel, cassette, and right hand brifter that will work and work well? Its a lot easier to get parts to work that ARE compatible, than to try to mix brands, years, or cog limits. Keep checking ebay.

  12. #12
    DRF aka Thrifty Bill wrk101's Avatar
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    Double check your spacing. It is surprising to me that it is 130. Of course, since it is a steel bike, you can pretty easily squeeze a 130 rear wheel on it without much bother.

    I would be hunting RSX stuff. There are two ways to get it. One way is the ebay option which you are pursuing. Note that others are looking for that seven speed stuff too, so it will be competitive. Or two (my preferred option), pick up a RSX equipped bike, and swap components. I have found multiple RSX STI bikes on the used market, at reasonable prices. Put DT shifters on your donor, resell it and get more of your money back, and then put the RSX STI on your bike.

    You may even end up picking up a better bike. I recently picked up a nice 1995 Fui Roubaix, all 105 eight speed STI. I wasn't looking for one, but I could not pass it up.

    The other advantage of the RSX over the SORA is that it is all rebuildable, at a reasonable cost.

    You can also still find right hand seven speed SORA STI brand new at chain reaction cycles. They don't have the matching left side, but you could use the eight speed version of the left side, and be ready to go. At $42 for the seven speed STI, I have been thinking of ordering a few just for future projects. Seven speed conversions are pretty popular.

    http://www.chainreactioncycles.com/M...?ModelID=45708

  13. #13
    Gear Combo Guru Chris_W's Avatar
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    Another option: Get a 9-speed cassette, 9-speed chain, and some 9-speed STIs (new Tiagras, or old 105 or Ultegras). 8 of the 9 cogs should fit on your 7-speed hub and use the limit screws to block off the ninth position in the STI. I would actually put the extra position at the high end, so the shifter can go into that position but in fact the cable just goes slack and the derailleur doesn't move. If you ever decide to change the hub, or at least the freehub body then you can put the 9th cog on their and you're all set.

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