Tapping French to Italian on my baby

Discussion in 'Cycling Equipment' started by rednaxela, Jun 25, 2007.

  1. rednaxela

    rednaxela New Member

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    Bottom line up front (a couple para's down): I need a recommendation for someone to retap my steel frame with French threads to Italian in the DC metro area.

    The rest is largely maudlin rambling. Or flavor. Your choice.

    I bought a steel frame road bike from the little Italian shop just down the street from post in 1993. Lovely bike, fun to ride up the foothills of the Alps when I was in way better shape than I am now. The shop was "Fabris Bruno" in Vicenza. Appears to have closed down in 2003. He probably outsourced to one of the major manufacturers (Campagnolo is a Vicentino company, Bianchi isn't too far away, but I have no idea who actually built the frames.)

    Fast forward 13 years, I get a job that allows me to ride the 14 miles to work two to four times a week. LBS#1 says "Buy a new bike," but the only thing I ride that feels remotely like my old bike costs 2 grand. Um, No. LBS#2 gets me up and running. I start logging about 100 miles a week. Now I've got the bug, figure it will be edifying to upgrade the bike sua sponte. Do a little research, and figure it would be fun to upgrade my 105/Tiagra/Suntour misto groupo to, say, Ultegra. Check Sheldon Brown's bible, measure the drops, and $300 later I have a nice used group with everything but a bottom bracket.

    Finally get a little time to pull the cranks and the bb, only to discover that it's French threads with a 5N spindle.

    Internet research round number one reveals that Shimano does not manufacture BB-6500 in French thread. Oops.

    Internet research round number two indicates that nobody - not Phil Wood, not nobody - manufactures a French thread BB that's compatible with an Ultegra crankset.

    Internet research round three reveals Leonard Zinn column indicating I can get a French threaded BB retapped to Italian threads (which would accomodate a BB-6500): http://www.velonews.com/tech/report/articles/11164.0.html

    SO:

    Anyone have a LBS in the DC Metro area they'd trust to do this job on their essentially unique Italian steel frame? That they love? And don't really want to replace?

    PS. If you think there's a French threaded bottom bracket compatible with the Ultegra crankset I have in hand, I'd love to hear about it.

    Thanks to all.

    Nick
     
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  2. artemidorus

    artemidorus New Member

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    Come on, all! For once, there's a good technical question here rather than some bleat about having no idea how to patch a flat tube. I've got no idea, this is way beyond my level.
     
  3. sideshow_bob

    sideshow_bob New Member

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    the problem is it's limited in geographic location

    i'm sure there are fabricators or independent frame builders in the continental us who can do it, but in the DC metro area? personally i'd be not looking at LBS this type of thing is not what most of them have the capability to do. for example the one guy in sydney i know i'd talk to, isn't a bike shop he does bike specific metal fabrication in a few different materials.

    i think he might want to consider looking further afield, but then it raises the question does the shipping and cost (which i wouldn't assume to be cheap) make this a worthwhile exercise.

    good luck is all i can offer to the op, hope you can get it done.

    --brett
     
  4. Powerful Pete

    Powerful Pete New Member

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    I think you have to go to a frame builder to field a question like that, and I have no idea if you can find a frame builder in the DC area. Google some of the more well known American frame builders and see what they tell you.

    N.B. I doubt it makes sense financially, but then again, riding is not about making financial sense.
     
  5. alfeng

    alfeng Well-Known Member

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    Are you committed to the Octalink BB for your French bike?

    How much are you willing to spend (NO, I don't have one to sell you)?

    Here's the KLUGE for updating any French frame with a contemporary BB -- it might seem a little dodgy to some, but I am fairly certain that all you need are TWO of the older (non-cartridge) Dura Ace Octalink bottom brackets with English threading ... because, as you know, both the French & English BB shell are 68mm in width.

    Way-back-when, when I was upgrading my Gitane, I had installed a SUGINO English BB's adjustable cup + Campagnolo French FIXED cup into the frame ...

    Because the English threaded adjustable cup is slightly smaller than the French threaded shell, the English cup not only seems to fit, it does (WRAP SOME TEFLON PLUMBER'S TAPE AROUND THE THREADS) ... well, it does, well enough, IMO (obviously, Sheldon Brown -- and, probably others -- disagrees).

    I did NOT perceive any problems at the time (yes, ignorance may have been bliss!).

    So, you really just need the TWO adjustable cups (non-driveside) with English threading (plus the rest of the BB assembly, of course!) from the original, non-cartridge Dura Ace Octalink BB ... et voila, you have a de facto French Octalink BB.

    Conspicuous consumption? Well, the BB is rarely visually conspicuous, but it is tantamount to "conspicuous consumption" since you need to acquire a second non-driveside cup and the easiest way is to simply buy a second BB.

    With the ALLOY Dura Ace cups, any inconsistency in the thread pitch will be "fixed" (!?!) by the steel threads of the BB shell AND the Teflon "plumber's tape.

    Yes! This also means that TWO non-driveside, English threaded, external bottom bracket "cups" can be used to install a Hollowtech II, Mega-Exo, or Campagnolo crank on a vintage French threaded bike. The GXP is problematic unless the cartridge bearing from the driveside can be fit inside the non-driveside cup (OR, you can use a non-driveside Campy on the driveside, I suppose).

    The caveat is that somewhere down-the-road, when someone else tries to remove the driveside BB cup, s/he will find it to be impossible because t/s/he/y will presume it has a left-hand thread instead of the right-hand thead!

    BTW. Even though you already have the crank you want to install, it may be EASIER to get an extra, English threaded non-driveside EXTERNAL BB cup & install a contemporary, two-piece crankset -- heck, if you can get two EXTERNAL non-drive side cups, separately, then you just need the plastic sleeve to complete the BB.

    FWIW. This is something I had been giving serious consideration to doing with one-of-two French threaded frames that I still have, but for the time being, I simply installed a square-taper UN-71 cartridge in one of the frames ...
     
  6. rednaxela

    rednaxela New Member

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    Thanks, Alfeng. I hear what you're saying, and I bet it would work fine, but I'm not comfortable cross threading to "fix" the problem.

    Discovered that Phil Wood makes french cups for his bottom brackets. So now it's a cost v. risk analysis of (a) retapping to use a standard shimano bb with my existing cranks against (b) installing a Phil Wood square spindle and getting a new set of cranks.

    Obviously less risk with (b), but I'm not sure how much it would cost to retap. Will update for giggles as I go.

    Nick
     
  7. alfeng

    alfeng Well-Known Member

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    Well, WHY pay the premium for a Phil Wood BB unless you are going on a round-the-world tour? Even then, while it MIGHT have made sense 20+ years ago to have a maintenance-free BB, I just don't see a Phil Wood BB as being better than a high-end Shimano cartridge BB, now -- the reputation for SOME Phil Wood products exceeds reality, IMO.

    On my French frame into which I installed one of my "extra" SHIMANO UN-71 cartridges (the better Shimano cartridges are, as you might expect, smoother than the less expensive ones, particularly than their OEM-grade cartridges) which was going unused [BTW. some of the Shimano cartridge bottom brackets have "removable" cups ON BOTH SIDES, particularly the ones with Italian cups], I used the ORIGINAL (non-SUGINO/non-CAMPAGNOLO) bottom bracket cups.

    The Shimano cartridge had 2mm of "float"/play which I thought was "too bad" for me ... you know, I hoping for the "perfect" & effortless retrofit without any additional effort on my part.

    Fortunately, the "float" corresponded closely to the necessary asymmetry if the cartridge was "shimmed" ... the shim was easily accomodated by bending an "extra" 2mm (14g) spoke into a crude wire donut which was approximately the size of the diameter of the cartridge & "placed" onto-the-end of the cartridge before inserting it into the BB shell (the shim is self-centering because the cup is concave). If your particular cups are Campagnolo or Sugino (yes, I actually have BOTH, but I didn't bother to check the fit of the SHIMANO cartridge in their respective cups because why bother "wasting" them if the unpolished races of the original cups would suffice to hold the cartridge?) then the inner dimension of the cups may be different, and so getting the offset may take a little more tweaking -- that's actually a good thing even though it means an extra step, or two, in fitting.

    So, to repeat, if you're going to continue to use a square taper spindle AND you aren't going around the world on a cycling tour, then I don't see the point in putting a Phil Wood BB in your frame simply to replicate what you have.

    BTW. Before I sold my Gitane, I put the original BB back on the bike ... again, no problem with the threads. Neither the French shell nor the English cup was affected by the experience.

    BRITISH THREADS == 34.8 x 1.06
    FRENCH THREADS == 35.0 x 1.00

    We're NOT talking about NASA tolerances here ... if anything, the slight TPI variance is what makes a raw (sans Teflon tape), smaller British threaded cup seem to fit so "perfectly" inside a French shell!

    IF you are giving serious consideration to having your frame re-threaded (!) at what I presume will be a cost in the range of $30-to-$50 (is it going to be less?), then you have nothing to lose by inserting an English threaded adjustable cup on EITHER side. You may be pleasantly surprised at how well it actually fits (I didn't use Teflon tape way-back-when ... it's just what I would probably try to do, now).

    ALSO, not all English-or-French BB shells can be safely retapped to the Italian Bb thread size. Cheaper frames, possibly yes, because the BB shell is undoubtedly less refined (i.e., more robust, thicker). Nicer frames, probably not. Without dragging your frame to a shop, put a tape measure on the shell ... think about how thin the remaining shell will be if you wallow out the inner diameter by a millimeter (i.e., a half-millimeter reduction of the shell's thickness) -- it would probably leave the shell only a little more than 1mm (or, less!?!) thick where the threads are!

    While rethreading a non-Italian BB shell to an Italian threading may have been done ONCE (if ever ... I do remember reading about this being done decades ago as a "fix" for a frame whose threads had been damaged which might have been the source for the continuing re-telling, but I'm almost inclined to believe that it was an "urban legend" OR that the frame did not survive many seasons of serious riding UNLESS a bolstering collar was eventually brazed around the both sides/ends of the BB shell). OR, it might have been done on ONE BIKE for ONE RACE ... in retrospect, I can't imagine that it was a viable, long-term fix for the "problem" you are addressing.

    Obviously, your best bet is to find a local framebuilder who will be able to assess your frame & "desire" for you ... possibly, do the work, too. Aren't Richard Sachs & Harry Hovnanian on the East Coast? I don't think they have Italian threads on their bikes, but they can probably recommend someone near you.

    FWIW. I also ended up retrofitting a Shimano cartridge into a proprietary 71mm wide Raleigh BB shell ... a little more "effort" ... although it didn't have to be!

    If you are opting for a Campagnolo taper, the cheaper AC-H cartridge BBs (e.g. Mirage) have removable cups from the cartridge and MAY fit into the cups you already have. I don't know the diameter of the the particular Campagnolo cartridge. Different cups -- again, to state what may be obvious -- have different in "interior" sizes. If the cartridge (whatever brand) floats inside the cups, think of that as a good thing since it will allow you to dial-in the alignment.
     
  8. John M

    John M New Member

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    Another option if you go the square taper route that is cheaper than the Phil Wood is to use a replacement BB designed for use in frames that have stripped BB shell threads. Both YST and stronglight make such a product. The YST is pretty cheap an maybe you want something nicer. The Stronglight is akin to the old MAVIC BBs that required chamfering of the BB shell. Also it is hard to find, but can be ordered from the UK online.
     
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