becave7

I am building up a small frame Cannondale R600 for my son and found a set of Shimano Sora 3300 STI shifters with a triple front. Does anybody know if it's possible to use this on a front 2 sprocket setup? I was thinking maybe just using the limiting screws, but not sure that would work. I don't want to setup and waste the cables if it won't. I could buy a used double and sell the triple but wanted to get this done sooner, before it starts getting hot here and we are on a very tight budget.

Thank You
Brian

Mobile 155

You can set the limiting screws and it will work. Not as well as a derailleur set up for a double but it will work. Just watch for chain drop now and then.

shelbyfv

It will work perfectly. You will have a choice where you have the extra position, there are pros and cons either way.

Retro Grouch 

9-speed Shimano groups used the exact same front shifter for double and triple cranksets so I'm pretty sure that you'll be able to make it work.

My 9-speed Ultegra shifters had 4 shift positions. As a double they provided 2 shift positions for each chainring. As a triple they provided one position for the granny, two for the middle ring and one for the big ring. FWIW, set up that way a Flight Deck computer would always indicate the correct chain ring that I was in.

Mr IGH

I run a 3x on a double and use the two outer shift indexes (two outer ring indexes). The cable goes slack if/when I shift into the first index (inner ring index) but I haven't had any issues, works very well.

Maelochs

I use Shimano Tiagra triples on two doubles---no problem.

becave7

Woohoo, you all just made my morning! I figured it would work somehow and I really like the idea of having two shift positions for the the most used gear to avoid chain rub. This will be on my 11 yo son's bike and he has yet to ride a nice road bike or sti shifters. I'm a little worried but he will figure it out quickly.

I'm building a 1976 Gitane with a single front for him as well. Keep finding 50cm bikes here, I'm up to 4 and found 2 more for 20 each, haha. Just found a 1981 Trek 410 for 20 but needs a lot of work. Still, kiddo is getting spoiled. Now if I can find something my size.

I need to find the bottom bracket cable guide for this frame. It didn't come with one and won't work without it.

Mr IGH

BITD we routed the cable under the bottom bracket, between the chainstay bridge and hooked it up to the derailleur. It works very well and doesn't require a bracket. These days frames come fitted with a plastic guide on the underside of the bb, it does the same thing only doesn't damage the paint (which no one sees).

becave7

Yes, my steel 87 Trek is setup like that and has grooves cut in the bb to keep them from slipping sideways. I do put a little grease on the cable to make the frame last longer. This Cannondale R600 frame is like new and I want find that piece to save the frame and paint. The frame is aluminum and very light and thin. I found the cable guide on eBay for about 10 dollars. Hell a small length of cable housing and some glue would probably suffice.

My son is really stoked about this bike because it is just beautiful, light and has carbon forks, haha. If it doesn't work out, I figure we could trade it or sell it for an MTB upgrade for him!

Mr IGH

If you're worried about cutting through the frame, use a Teflon coated cable. Just a point of reference, brazed on cable guides have been used for years and nobody has ever cut through one, bb are much thicker, you'll never effect the integrity of the bb.

shelbyfv

Those plastic bb cable guides are often generic. Maybe you can just use one from one of your other bikes.

becave7

All of my other road bikes are about 1970 to 1987 and don't have those guides, haha. We searched through a bunch at the bike co-op and didn't find one that fit at all. The CAAD3 design is a little weird I guess. No worries, we will at least find something to seal the little hole in the bb that the guide was supposed to mount to.

Thank You all for the suggestions. Can't wait for my son to have his first experience on a nice road bike.