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Downtube shifter to STI upgrade. Is this possible?(13 posts)

Downtube shifter to STI upgrade. Is this possible?Rob11966
Jan 4, 2004 3:39 AM
A mate of mine has asked me to help him upgrade his downtube shifters to STI. I have an old 105 set from a bike of mine a while ago that I will donate to the cause. Does anybody know if shifter lugs located on the downtube (of the old frame) are compatible with the 105 downtube cable guides? Never worked on a bike that old!
re: Downtube shifter to STI upgrade. Is this possible?Rusty Coggs
Jan 4, 2004 6:55 AM
The ones I have seen brazed in were pretty standard and accept the cable guides.
... fundamentally, yes...Akirasho
Jan 4, 2004 7:03 AM
... if his frame has downtube bosses, Shimano makes and supplies (generally with any road gruppo) the necessary inline adjusters...

Be the bike.
DependsSpoke Wrench
Jan 4, 2004 8:00 AM
The issue has to do with how the down tube shifters attatched to the frame. Through the years there have been at least three different methods and the Shimano supplied cable guides will only work on one of them. If it's a standard tube size steel frame, you might be able to locate a clamp on set of cable guides but they look kind of cheap. I also vaguely remember retro-fitting a bike several years ago, but I don't remember where I got the hardware and it required drilling the down tube.

Good luck.
andWoof the dog
Jan 4, 2004 10:04 AM
can the guy even have STI on his bike if its 7 speed. I don't think they had sti for 7 speed, but then again iwasn't into biking then.

two optionslaffeaux
Jan 4, 2004 10:16 AM
RSX came as a 7-speed STI shifter. If you find an older set it's possible to have 7-speed STI shifting.

Also, as long as it's a steel frame, or if the frame is spaced for 130mm hubs, you can always upgrade to 8 or 9 speeds.
You're right but...Spoke Wrench
Jan 4, 2004 11:48 AM
This is turning a simple shifter upgrade into a major project. Truth is, you can almost never change just one part on a bicycle. Sometimes I think it might be easier to carefully unwrap the handlebar tape, replace everything else, and then rewrap.
easy, do it!wooden legs
Jan 4, 2004 12:18 PM
go for it, i've upgraded several mid 70s to mid 80s bikes from downtube to sti, as long as the cable guides fit on the downtube shifter bosses, everything should go smoothly. as for 7 speed compatibility, it's probably a better idea to just switch to an 8 speed wheel / cassette in the rear and use some of the thousands of used 8 speed stis floating around. most any frame that accepts a seven speed freewheel will accept an 8 speed wheel with a little elbow grease.
Jan 4, 2004 12:28 PM
I am giving him my 8 sp wheels and rear derailer - He is going to buy a cassette.
Sorry - didn't make it clearRob11966
Jan 4, 2004 12:34 PM
I am planning to rebuild his bike with full 105 including the brakes. I will also 'loan him' my old 105 wheelset. He is going to buy cables and the rear cluster. Thanks all for the practical advice.
andRusty Coggs
Jan 4, 2004 12:48 PM
Besides the old RSX 7 speed STI, I think sora is available as 7 speed. 7 speed cog spacing is close enough to 8 speed that 8 speed STI usually work with 7 speed shimano casettes.
I did the opposite!4bykn
Jan 4, 2004 4:23 PM
When my '92 Ultegra sti shifters died, I saved a few bucks and put downtube shifters on. Of course this is my back-up bike.

Ride in Peace...Mike
Going to do the same here.the bull
Jan 4, 2004 7:19 PM
Spacer in the 8-9 speed hub so I could put a 7 speed cassette in there, used a 10 dollar 8 speed chain, and put some downtube shifters on the downtube. Reliable no-hassle rain bike.