himespau 

Not really a C&V question, but I'm not sure who else to ask. I'm trying to build a frame (1989 Colnago Super) that's been giving me all sorts of problems (not tubing advertised, rear triangle and seat tube diameters smaller than advertised, fork crown race seat 26.7 mm instead of 26.4, etc.).

My latest problem is the front derailleur braze on is lower than I'd like. I'm trying to run a 53-42-30 triple on a 10 speed system, but I can't get any of my FDs to work.

I have a Record FD that I used on a previous bike (until it got hit by a car) that shifted perfectly on that bike with the FD mounted right in the middle of the braze on. If I push it all the way to the top of the slot on the Colnago, it still hits the teeth of the outer ring (just barely, I first tried it with a 54-42-32 crankset and it hit a bit harder).

Same thing is true for a Mirage Triple FD from a 3x9 setup.

I even decided to hold my nose and try an old Ultegra triple FD that I had sitting around (nothing wrong with it except entire bike is Italian). The outer cage will clear the outer ring (at least as far as I can tell), but the inner cage won't clear the middle ring (it was designed for 52-39-30) even when set as high as it will go.

Does anyone know of a triple FD that has a lower mount so that I can get it to work in my setup?

Or is there a way to get my FDs just a touch higher?

Alternatively, I think if I could somehow angle the FD up, it would clear as it's just brushing the teeth near the end farthest from the pivot.

thanks.

himespau 

Does anyone have any experience with the microSHIFT 539? I wonder if those have a lower mounting bolt. Certainly affordable and are designed for 52-42-30.

I mean I suppose I could always hunt down a 50-39-30 crankset instead (supposedly those have a 3-4 mm shorter radius, so it should clear), but I like the gearing of the ones I have. Plus, this bike was built in the 53-42 chainring era, so I'm confused that even a triple where the 53 is much farther out than it would be on a double is getting hit. I am using a 115.5 mm spindle, which is the recommended for Campagnolo triples.

himespau 

I could get some new rings, run a 50-40-28 crankset (which might fit my current derailleur) and see if I can find that old 11-25T cassette instead of the 12-25T that's on there. That'd give me a wider range including a lower low, but I'd lose the 16T that I really like.

I'd be bummed to source 3 new chainrings and still have the same problem.

I only care about the high end of the gear inches because I'm doing most of my riding right now on the trainer and it doesn't have much resistance, so I'm usually in the 53T ring and 12-15 (maybe use the 16T for warmups, but usually not).

I'm getting tired of waiting to ride again, so, for a trainer build, I might just build it up without a FD (run the cable to the seat tube and tape it there) and ride it as a 1x on the trainer until I get an FD figured out or I decide to source new chainrings. I don't think I'd get a lot of dropped chains without a keeper just riding on a trainer and shifting in the rear, would I?

I am seeing some 9-speed campagnolo chainrings. Would those work on a 10 speed crank with the bolts from the 10 speed?

Should I ask to have this moved to mechanics? I just put it here because I'm restomoding a 30+ year old frame and many folks here do that.

mgopack42 

I had te opposite problem when i went sub-compact on my Masi; the FD was too high at the lowest point of the braze on. I used a round file and adde a couple of mm to the slot in the braze on. you may not want to "deface" your classic bike, but i look at these things pragmatically. got the shift performace i needed, and everyone is happy.

himespau 

Fair point. I'm less concerned about defacing my classic bike than removing too much material and damaging the structural integrity. Don't trust myself to have a steady enough hand to dremel it off completely if that happened. I wonder if there is an assymetric washer (kind of like for brake toe-in that I could find to tilt the FD.

73StellaSX76

I’ve ground the lower profile of the outer blade of an fd to match a ring radius better. Sounds like you only need a mm or so. That removes chrome so reduces rust resistance, but so much lube collects there anyway it’s not much of a problem. By this you’re modifying your fd vs your frame.

himespau 

Huh, I like that idea. Never occurred to me that was even possible. I suppose, even if I removed a couple mm, it wouldn't affect structural integrity or ability to shift much.

himespau 

Is that a triplizer middle ring? Cool. Do those come with the pins on them to help with the shifting?

73StellaSX76

Hold a Sharpie against the crank arm and swing an arc on the blade at the depth you need.. Grind to the line, blend and polish both ends. 2 or 3 mm over the short length you need won’t affect structure much. The one I did shifted well.

SJX426 

@himespau - I had nearly the exact same issue when building the De Rosa. Unbeknownst to me, I purchased a triple FD thinking it was a double. It would not go past the outside ring. That is when I discovered there is a difference in the arm length of the FD. I purchased a double FD and it fixed the issue. Then I had a triple FD with no triple bike.
My riding has dropped like a rock this last year. There are a couple of steep hills I really struggle with on the main ride, a Pinarello 8v. The De Rosa is a 10v with a lower gear by 2 teeth that makes a big difference. It was time to consider a triple for the Pin.
Did the conversion with the result of the triple FD working just fine with the longer BB spindle for the triple crank.
P1030490 on Flickr

P1030474 on Flickr
P1050202 on Flickr

I could not find a braze on double FD. Fortunately Campagnolo designed the FD to be mounted either with a clamp or braze on. Same FD different mounting interfaces with a common interface with the mounting hardware.

It is the upper Alan head screw that is removed to change the mount. The other pivot just slides on and off. Gotta pick your parts for similarity!
P1030472 on Flickr

himespau 

Yeah, I have a triple FD, triple BB spindle (115.5 for this generation - oddly, I was able to get one of the FDs I tried to work with a 111 spindle and a triple on a previous build - braze on must have been higher), triple crankset. I see angled shims for the FD, I might try ordering one of those. Unfortunately, they're all in China, so it's not a quick fix.

cyclezen

Colnago... since the late 70's, Colnago was pumpin out a slew of frames,bikes... by many builders... If you had a brazing torch, and were in Italy, you became 'family' and was put into service brazing frames. My road Colnagos, a late 79 Super in the 'Saronni' colors and chrome fork is a outlier as far as rear triangle specs go... An 84 Master, which again is a bit of a tween of the later Masters and earlier Mexico (but with Gilco...) All a long story... frames, gotten in Italy... , good back stories... Anyway. Don;t be put off by 'specs outside of catalogue'...
They're still fabulous bikes...

The FD hangers are quite strong, especially when there's a FD in them... don't ask me how I know... LOL!
You've already been given a good tip to take a bit off the hanger slot... I would agree, file...
Put the dremel aside, get 2 round files of that dia., one a bit coarser, one a bit finer, and patience on the filing... emery cloth to take the sharp edge off, some clean up, touchup paint, and no one will ever know...
LOL!
Thx
Yuri

himespau 

I may look into getting a couple of new files (new tools, hooray!!!), but I'll probably try tilting the FD, modding the FD, and maybe changing chainrings first. The angled shim (assuming it arrives from China) is only $13, modding the FD is free (other than time, wear on the dremel grinder wheel, and maybe a broken FD). Changing rings could get pricey, so I might skip that one (especially as I like my current gearing). Cheapest/easiest fixes first and all that.

davester

It seems to me that a better alternative to grinding the cage blade/plate would be to grind off the lower part of the mounting stud where it contacts the braze-on. That should get you a couple of mm without any impacts to function or aesthetics.

squirtdad

mgopack42 that look pretty cool can you provide some detail on what you did, bb size etc? or point it out if it is in another thread or start a thread? this is of lot of interest to me thanks

himespau 

Not sure I'm understanding you. Are you talking about the bit that goes through the braze-on that I thread the nut too? Grinding that seems like I'd lose strength in a hurry.

davester

Yes, that's what I'm talking about but I made an error. I meant the upper part of the stud, not the lower. You can grind off the thread portion without losing ant strength and then perhaps a mm more.

mechanicmatt

If you are uncomfortable, just get a nice round file in the appropriate size. Work at it slowly and there will not be any accidental over doing.

himespau 

Ah yes, it didn't occur to me that the threads add diameter without adding strength.

mgopack42 

I added a thread of my tripleizer by request

himespau 

Don't know if I have it rotated differently, but now it seems that it's the front of the outer plate, not the back side and it also seems to be a lot more contact than I'd remembered. It could be I was remembering looking at the Mirage 3x9 FD rather than this Record 3x10 FD. Anyway, here are pictures so you can see how much the contact is. Sorry, my precision rule is only SAE not metric as I'd prefer.

jccaclimber

For the record, the threads on a screw do add strength. This is why for calculations the stressed diameter is larger than the minor diameter. That said, you’ll probably be fine, it’s a small portion.

A few valid solutions have been listed. You could even do a combination like filing through the threads on the stud so that you don’t have to take as much off the braze on.

Hand tools seldom get out of control. Cover any painted surfaces with a few layers of tape or some card stock and tape if you’re worried about an errant file stroke.

SJX426 

@himespau - For another reference, the distance from the BB center to the bottom of the braze-on is 13.5mm on my 89 De Rosa.

himespau 

When I pulled the crank off last night to re-measure the BB spindle (it says 115,5 on it, but wanted to make sure that's what it was), I really should have measured that distance. Thought about it immediately after I'd put it back on because I could compare to my Concorde Aquila where the same FD sat square in the middle of the braze on to shift a similarly-sized crankset, but I'd just pulled it and didn't feel like doing it again. Probably could have used a stick or something to extend the bottom of the braze on out into space, but that didn't occur to me at the time. Measured from the top of the bb shell where the lugs stick out, the braze-on on my Concorde Aquila was about 1/8" higher than this problematic Colnago Super (there was more than 1/8" between the top of the slot of the braze on and the stud of the FD when it was on the Concorde, so I don't know what's going on), but the shells could be different thicknesses or extensions from the lug or something could be affecting my measurements.

himespau 

Honestly, losing a little paint isn't something I'm worried about. I have some Testors paint that's a very good match for the color/metallic sparkle that I used to fill in a couple of small scratches that went down to the bare metal on this bike already. Or I could just do clear nail polish. I haven't seen too many FD braze ons rust even though the FD often bites through the paint anyway (I'm more concerned about preventing rust then cosmetics when I do paint touch ups).