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-   -   Sun Tour Reverse Pull Front Derailleur Replacement Options--Vintage Santana Tandem (https://www.bikeforums.net/bicycle-mechanics/819946-sun-tour-reverse-pull-front-derailleur-replacement-options-vintage-santana-tandem.html)

msvphoto 05-22-12 12:34 PM

Sun Tour Reverse Pull Front Derailleur Replacement Options--Vintage Santana Tandem
 
I am having a very hard time getting a reliable shift into the small front chain ring on our new-to-us vintage Santana road tandem, especially when we need it most (read when the Cap'n f's up and doesn't shift early enough). After riding with it this way for a couple hundred miles and adjusting both the FD and all the slack out of the cable with minimal improvement I am ready to give up on this derailleur. It seems to have a lot of slop if I grab and move the cage, which could be a major part of the problem. It is my understanding the reverse pull was intended to make it easier to shift to the small ring, but this one sure doesn't work that way!

I kind of want to convert to a "normal" FD, but there might be a minor challenge. The FD is a Sun Tour "reverse pull" with a cable housing that runs from a cable housing stop on the underside of the stoker's BB to another cable housing stop on the FD. With this cable routing I need to get creative to use a conventional FD since normally there is no housing and in this case the cable stop location would have bare cable riding against the back of the BB shell and up the stoker's seat tube. Since the cable routing is on the underside of the boom tube using a clamp-on FD cable guide isn't an option. My old Kestrel 4000 road bike has a similar cable routing issue (internal routing in this case) and their solution (as told to me by Kestrel in Watsonville, CA when they repaired and painted the frame about 16 years ago now) was to sleeve the cable (no housing, just the nylon inner sleeve) to route the cable from the BB up, so that is one idea. Another idea was a short chunk of housing to get around the BB shell, but how to terminate the FD end comes to mind--possibly a clamp-on cable stop.

Anyway, looking for suggestions of what I should replace this derailleur with and how best to route the cable to it. A vintage reverse pull Sun Tour is a possibility, but I'm thinking more like a Shimano of some higher end flavor (XT, 600, or Dura Ace perhaps?) might be a better way to go. The chain rings are Sugino, old-skool (not ramped and pinned). The shifters are bar end friction.

Sixty Fiver 05-22-12 01:19 PM

I have always like the reversed pull Suntour front derailleurs and if it is simply a matter of the old d being worn out I would try replacing it with the same derailleur first and if that did not work, look to using a different derailleur.

If you can't source one locally feel free to send me a note as I have quite a few of these and even have some NOS ones.

fietsbob 05-22-12 01:36 PM

You might also consider Putting the FD and the final drive
triple crank.. Up front, captain's crankset.. then You can see whats going on,
and use what you will find, Low normal rather than the High normal where the return spring
pushes the mech to the big ring, cable pulling it to low gear is a good thing,
but the marketplace went the other way.
When tandems were built up in the 50's the drive chain was the long one,
[ being That long , no cross-chain issues ]
the timing, crossover chain, the short one.

There is the pulley to re direct bare cable

and I've had Bikes that push the FD actuating arm, with the housing ,
and the cable is anchored on the frame.

Newtonian..

msvphoto 05-22-12 05:57 PM

Thanks for the replies. I'm kind of thinking it is just worn or damaged. Worn would be hard to believe because this near 30 year old tandem looks like it came out of a time capsule so it was either really well taken care of/maintained, or has very low miles. The cage moves around quite a bit when I grasp it and wiggle it. Sounds like the best solution is go with another like it if possible. The only reason I was thinking about going conventional is I likely have one laying around I could try, just not reverse pull.

@ Sixty Fiver I'm not anti-Sun Tour at all and I do rather like the design. Finding used ones in decent condition isn't easy. I'll check with a few LBS's that have vintage stuff first, and if I strike out there I'll take you up on that offer.

I can see the chainrings fine so that's not an issue. Many decades ago I went with no FD on a road bike, just picked the chain up with my fingers and moved it over, in total weight weenie mode--that mindset is, thankfully, long gone.

oldskoolwrench 05-22-12 06:14 PM

Perhaps a couple of photos around the area in question (cable routing) would help; personally I have to look at it for a few minutes (hours, days, etc.)
before I can visualize if something will work or not. I'll have to see if I might have a good Compe-V FD in my parts bin, if that would help.


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