Old Simplex derailleur not playing nice with my crank

Discussion in 'Cycling Equipment' started by cloudhead, Jan 10, 2011.

  1. cloudhead

    cloudhead New Member

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    Hello, any friction experts out there?

    I am restoring a touring bike from 1985 (Trek 720) and am having some issues with the derailleur and crank. The derailleur is a Simplex Pro LJ touring model, with a Velo Orange Grand Cru 50.4BCD (basically a TA reproduction).

    When at the highest gear, the derailleur cage hits the crank arm. It appears to be vertically-angled as well as bowed, and I am curious if that is normal for this derailleur, or if some expert adjustments are in call. The bottom of the cage protrudes out significantly more than the front.

    If i limit the high adjustment any more in front, i get grinding when I am at the highest gear. I love both these components and hope to make them work, but if it just isn't going to work, I am more interested in hanging on to the crank than the derailleur if it comes down to that. The original crank on this bike was a Sugino triple. Now it is a double. I don't know if that makes a difference.

    Thanks for any advice,

    Court

    Link to crankset:

    http://store.velo-orange.com/index.php/components/cranksets/cranks/grand-cru-50-4bcd-crankset.html

    [​IMG]

    [​IMG]
     
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  2. ReneHerse

    ReneHerse New Member

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    Seems that the cage of your front derailleur is bent. I've exactly the same model and both cage plates are 100% parallel (outer width 15mm). The gap between crank arm and chainring of my original TA 5vis is only 7mm and nothing rubs.

    Dirk
     
  3. cloudhead

    cloudhead New Member

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    I was hoping to read a reply like yours. I'll get the pliers out. Thanks. Beautiful bike, by the way.


    -Court
     
  4. alfeng

    alfeng Well-Known Member

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    FWIW. Wthout knowing all of the particulars, I would suggest that your current/(recent?) problem may be caused-or-exacerbated by using a chain which is too narrow for the cage plates ...
     
  5. cloudhead

    cloudhead New Member

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    I found out what the problem is... The final versions of the Simplex triple was made for newer cranks with a larger Qfactor, and not for older TA cranks. I located an older NOS Simplex derailleur with a much lower and parallel cage, and look forward to its arrival.

    -Court
     
  6. alfeng

    alfeng Well-Known Member

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    You are going to have to humor me and tell me:

    WHAT (specifically) CHAIN ARE YOU USING?

     
  7. cloudhead

    cloudhead New Member

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    Shimano, SI-0450H (the 6/7/8-speed version), with a Shimano 7sp freewheel.
     
  8. alfeng

    alfeng Well-Known Member

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    FWIW. Since the Gran Cru crankset's driveside arm is 3mm further outboard (that's a considerable amount, BTW) then even If your recently acquired, "old(er)"/(pictured above) Simplex front derailleur was designed for a 5-or-6 speed drivetrain you should probably not be the experiencing rubbing/(contact) which you described.

    • Using a WIDER, 5-speed chain would probably resolved the problem, but then there would be a problem with the Freewheel ...

    • You may-or-may not recall seeing Campagnolo Strada cranksets which have a "rub" mark on the chain side of the driveside crank arm ... this was undoubtedly due to the wide cage plates on the Nuovo Record front derailleur + use of a narrower chain (e.g., SEDIS narrow -- the 8-speed Shimano chain appears to be a direct clone of the SEDIS chain)

    BTW. Why are you outfitting your 80s vintage frame with what are essentially 60s vintage (at least, in style) components?

    Why have you chosen a Simplex front derailleur(s)?

    PRESUMING, for the moment, that you have chosen the Grand Cru crankset for Rosebud-reasons (nothing wrong with that, BTW!), I think you should have possibly consdered either a Simplex or Campagnolo push-rod front derailleur ... viability depends (to some extent) on the seat tube angle ...

    • with a frame which has a 72º seat tube angle, for example, a derailleur will be able to accommodate a smaller front chainring without the chain dragging acrosss the spacer at the rear of the cage

    As it is, if 'I' were faced with your situation of opting for a vintage appearance, then I would take whichever front derailleur you eventually choose and ADD (as in, solder) an additional plate onto the inside face of the front derailleur's inner cage ...

    You will need to MECHANICALLY remove the chrome plating on any surfaces which will be soldered together ... you could either cannibalize the inner plate from another front derailleur OR some brass "stock" that you would buy from a hobby store ...

    I suppose that you could "glue" the extra inner plate onto the front derailleur, but glues can fail ...

    • If I were going to use epoxy (e.g., JB WELD) OR something like GOOP then the inner plate that I would add would have tabs which I could bend over the edge of the primary plate.
     
  9. alfeng

    alfeng Well-Known Member

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    BTW. Amending the distance between the front derailleur's plates to accommodate a narrower chain does NOT address the issue that there is something wrong with the particular front derailleur's plates not being parallel to one another AND not being parallel to the bike's central plane!

    So, FWIW, I think you should (if you haven't already done so) requested an credit-or-refund from whomever (presumably, Velo Orange) on the particular Simplex front derailleur (which I presume you bought as NOS) which you pictured on your bike.
     
  10. cloudhead

    cloudhead New Member

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    I have owned this bike since it was new, and most of the powertrain on this bike is original, except the crank, a Sugino triple, who's condition had seen better days. I also replaced the original gear cluster & hub which was a Maillard Helicomatic to a Shimano 7sp freewheel & Phil Wood hub.

    I thought I'd give the VO crank a shot since I always liked the TA cranks on my fathers old Raleighs. Something about the narrow stance, which also helps since I've had 11 knee surgeries--whatever it is, my knees hurt a lot less with this crank. However who knows if it will be "the one". I may go back to the Sugino... I like to tinker, especially on this bike. And yes, I don't mind a little "bling" on a touring bike.

    Thanks for the tips to check out. I'll see what other chain options are available, and I also have an older Simplex triple on it's way, which has a much more parallel cage and longer drop. If it doesn't work, im sure I can re-ebay it.
     
  11. alfeng

    alfeng Well-Known Member

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    ERRATA. I should have stated that the front derailleur plates should be perpendicular to the ground when the bike's central plane is perpendicular to the ground BECAUSE a good (perhaps, the only!?!) example of a front derailleur whose inner plate was NOT parallel to the outer plate is the second (?) generation Shimano Dura Ace front derailleur (c1980) which had slightly narrower spacing at the front of the cage than at the rear.

    [​IMG]

    Having the inner plate NOT be parallel to the outer plate was (probably!?!) pretty radical at the time -- and, I think it is indicative of Shimano's out-of-the-box thinking to improve the shifting (e.g., IMO, it was much better than either the Campagnolo Nuovo Record front derailleur & older Simplex push-rod front derailleur; and, last season I decided to see if I could reinstate it; so now, the DA front derailleur is installed on a bike [as pictured] with 10-speed Campagnolo Ergo shifters, 9-speed Shimano cassette & 9-speed Shimano chain) AND I reckon it has meant that more-often-than-not Shimano derailleurs will often work better than others from the same vintage ...

    Which is a long way of saying that if the second Simplex front derailleur doesn't work out that you may want to opt for a(n 8-speed) Shimano front derailleur whose cosmetics suit your fancy.

    BTW. I agree that the TA & VO cranksets are great looking cranks -- appreciation may be generational OR they may have a timeless beauty ...
     
  12. cloudhead

    cloudhead New Member

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    They are quite pretty, like giant watch components. This VO crank is "ok"... definitely a knock-off, but with good intentions. The modernized mechanism causes a protrusion of the bolt covers, which aren't very-well manufactured, and the allen key hole on it can tear up some street shoes, but regular cycling shoes are fine. I'll still be sending VO a note about that, and a friend with a metal fab shop is smoothing them out for me.

    (edit: I just checked out a vintage TA, and it apparently protrudes the same amount, so these covers are just in need of a better design)

    My bike mechanic also recommended an older Dura-Ace if I remember--do you have any tips as to what I should seek out? It will be much appreciated--I still yearn for riding in my 2 highest gears! I found a NOS Simplex Brevete derailleur, but the body is plastic and that scares me, especially considering price of the thing.

    Thank you
     
  13. alfeng

    alfeng Well-Known Member

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    FWIW. Based on the range of Shimano front derailleurs that I've seen (and, it isn't comprehensive by any means) over the decades, my impression is that for any particular generation of components, the difference is MOSTLY in the seat tube clamp ... and, the actual cage is close to identical from Shimano's high end to the low end groups ...
    • On the less expensive Shimano MTB front derailleurs, a steel band often comprises a part of the seat tube clamp ...
    • I think that all of the Shimano Road front derailleurs have alloy seat tube clamps; but, maybe not ...

    So, you really only need to let your aesthetic sensibilities be the basis for choosing whichever Shimano front derailleur you choose.

    • You want to match the front derailleur cage to the chain, so an 8-speed front derailleur will probably serve you the best

    A recent Shimano SORA front derailleur (I think it's intended for an 8-speed drivetrain) will serve you as well as a more expensive Shimano front derailleur ... I picked up a Sora front derailleur a while back when I was going to go with an 8-speed drivetrain on one bike, and it looks fine ...

    But, it might be worth tracking down an 8-speed, Shimano 105 front derailleur which was designed for a Triple (I'm not sure how rare they were-or-weren't ... there weren't that many 8-speed Triple-capable 105 shifters made).

    N.B. There is ONLY ONE Shimano front derailleur which I feel is sub-standard -- I deem the original DEORE (c1982) front derailleur to be as stiff as a wet noodle ... it is unacceptable (IMO) for a Triple, but "okay" for a Double with "Alpine" gearing.

    You could probably use an older, 80s-or-90s vintage Campagnolo "Racing T" front derailleur if the cage's outer plate has the cosmetics which you think better suits the overall look of your bike.

    BTW. Considering the price of those VO cranks:

    • as far as the unfinished Allen key hole, SOMEONE should probably have run the outer surface of the bolt covers against a whet stone before they were plated.

    • as far as the protruding bolt covers, it looks as though there is simply (?) about 0.5mm too much threading and if you draw them across a large Flat File once-or-twise, you can get them to nest in the bolt holes better than they currently do.

    Unfortunately, echoing AND/OR replicating French craftsmanship has its downside!
     
  14. cloudhead

    cloudhead New Member

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    Still working it out.... got all but the top gear without chain rub. My mechanic located an old Dura Ace front derailleur and also discovered that a narrower chain works well, better, actually. There's currently a SunTour derailleur of some type on there.

    I think my retro-modern crank experiment isn't going to pan out. Im thinking of checking the modern TA's or the Zephyr still at Peter White ($$$), or something close to the Sugino LP that was originally on the bike and provided me with thousands of miles of problem-free cranking. Not as pretty, but what use is beauty on a touring bike when it doesn't roll right. There's a lot of bits on this crank that makes it work well with indexed shifting systems, which is kind of it's selling point. However, I'm sticking with friction on this baby so I don't need those bits, and they are causing an issue--my mechanic had to do some serious fine-tuning with special tools, something i worry about when i'm out on the road and don't have a $2000 Park workstation next to me.

    The rear part of the powertrain is functioning perfectly, with a Phil Wood Rivendell Hub + 7sp freewheel and a Huret Duopar Ti derailleur (a derailleur that really spoiled me). Now if i can just get the front to work as perfectly...

    Thanks again for all the tips.
     
  15. cloudhead

    cloudhead New Member

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    Mission accomplished.

    I now have a Frankencrank made up of VO arms and a TA Chainring, which is much thinner. That, a 9-speed chain, and a Suntour Derailleur (all I could find for now) do the trick and I can now ride in top gear with minimal chain rub. The VO arms, while a knock-off, are 175mm which is good for my leg length. It shifts nicely and quickly. There is a little bit of chain rub when i apply a lot of torque, but I don't really ride like that on this bike anyways--was just a test.

    Thanks for the tips, and I also want to thank Tahn at WIllow Glen Bicycles in San Jose, CA for his research.

    [​IMG]
     
  16. cloudhead

    cloudhead New Member

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    By the way, I found a solution:

    • Ditched the VO 50.4bcd. It gave me nothing but problems. chain rub in all but 4 speeds. Apparently the new edition of Bicycle Quarterly confirms this. I have ordered a copy.

    Now I'm running a Campagnolo racing triple that I found on Ebay in NOS condition, added TA chainrings. The chainrings fit the crank ars so perfectly, it seemed they were made by the same company. A friend with a metal shop gave the crank a nice polishing. The bike's original Simplex derailleur is back on, but might be replaced due to its age and mileage. Nevertheless, all gears are happy and it rides like buttered silk. Now I can get on with my touring life!


    [​IMG]
     
  17. Eichers

    Eichers New Member

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    Hi cloudhead, now I can see the triple crankset you have ... very nice. Enjoy your touring :)
     
  18. cloudhead

    cloudhead New Member

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    Hi KLabs, thanks!

    This is actually a different bike-- my trusty 26 year old Trek 720 that I still run friction on. It's made more for slow easy riding under heavy loads, and I like keeping it adorned with classic components. Quite a different animal, and this one has a much lower set of gears than my other ride, which is a Dale Saso custom. Hard to decide which one to pick when I go riding tho! I usually ride this one in longer tours, uncertain terrains, and if I am by myself. The Saso is much quicker so it's good for club rides or if I feel like going fast.
     
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