dit

I have just purchased an Italian road bike frame and it has a fd braze-on that I did not notice before purchase. I am wanting to install a mtb triple crank and a compatable derailer. A clamp-on derailer bracket needs to go right where the mounting tab is located. Do I have any options? A normal braze-on fd will probably not adjust down far enough to get the cage close the small mtb outer chain ring. ( don't have one to try ) Should I just re-sell this frame and go shopping again?

joejack951

If you really want to use the frame, I'd look into making a new braze-on mount, or an adapter, which would allow you to drop the front derailler far enough to work properly. It will cost some money but you'll be able to use the frame at least. The other option, assuming the frame has round tubes, would be to remove the braze-on mount completely and use a clamp-on front derailler.

Gonzo Bob

Is the bracket fastened with screws? If so, it may be possible to replace it with one that hangs lower. I know there's a replacement bracket for using a compact crank on some Trek's but I don't know if you can find one that will get the derailer low enough for an MTB crank. What ring sizes are you planning on running?

dit

The crank set that I had intended to use has a 42 outer ring. The hanger is permanently attached and I hate to take a torch or file to a nice frame.

I also have a double that I can use but it also has a 42 outer ring. I live in a rather hilly area and there are some really steep hills to climb and my old legs don't like big gears. I guess I could consider a road triple to get the needed granny gear. I will need another crank set and bottom bracket. I assume there is a triple braze-on derailer available.

HillRider

Unless you can find an alternative hanger tab or remove the current one with no damage, you basically have the wrong frame for what you want in the way of gearing. It sounds like you are trying to build a touring or commuter bike and "Italian Road Frames" usually aren't made with that type of use in mind.

So either use a road crank triple and fd and compensate with your cassette choice or find a frame sutable for the crank and fd you want to use. BTW, most road triples can have the 30T stock granny ring replaced with a 26 or 24T and they will still work well.

dit

Well Mr. Hillrider I think you are correct. I really wasn't up for another crankset but.........I know it is not the norm but I am an old fart and live in a really hilly area and these old legs just don't like those big gears. I know I am a sissy but I don't want to give up riding yet. Grandpa rode into his late 80's as it was his only means of transportation. A big 90 pound balloon tire Schwinn no less. I hope I can too.

joejack951

Triple road crank with a 24 or 26T granny gear plus a wide range MTB cassette (one with a 34T big cog) and you'll have gearing about as low as most MTBs.

Retro Grouch 

Any possibility of making a top swing mountain bike derailleur work?

fuzz2050

The braze on is going to limit what you can do in terms of chainrings. Maybe you can fit a compact double, 44/34 or something like that, and pair it with a mountain cassette 14-34. That should be pretty low, and you won't have to do anything heinous to your nice frame

Deanster04

What is the Group you are planning to use? Shimano or Campy? Hillrider is correct on extended options.
Shimano: you can use an 11-34 MTB cassette by replacing the RD with either an MTB RD or an old 105 long cage RD. This along with a standard triple crankset and FD should work well. I don't know what the chain ring options are for Shimano triple crankset.
Campy Road: I have changed out the small ring to a 26t with the other 2 rings 40 and 50t for my normal road bike.
Campy Touring: I have a 26-39-48t campy crank set with T/A Specialities rings and use a standard Campy Centaur Triple FD. I changed the hub body on a Centaur for a Shimano Splined Hub body. I run an 11-34t SRAM cassette and a Campy long cage RD. The Shifters are Centaur 10spd ergos. This setup works extremely well as the cog spacing on the cassette is very close. I can easily interchange this wheel with a standard campy 10 spd wheel just making a minor adjustment of the RD set screws (5 minute job). I added a 3rd eye chain watcher to prevent the chain from ending up on the BB. The setup works extremely well. I am 65 and can ride anything the Rocky Mts have thrown me including the annual pilgrimage up Mt Evans (13Kft) and Trail Ridge Road in RMNP (12Kft). I have done TRR on the touring setup with loaded panniers (I am just slow but steady). I have setup friends (67, 70, and 72 yrs) rigs both Shimano and Campy and this has dramatically extended their range of riding.

The only thing you need to do is to determine where the chain rub occurs on the Crank set and limiit the shifting on the cassette. For example I only use the small CR with the largest 5 cogs before I get chain rub. I only use the small CR when the hills are steep enough to require it and then I will shift to the middle ring before I get to the middle cog on the cassette. I have used the campy 9 speed, SRAM 990 9spd, and 10spd chains (not the ultra thin) with this setup and have had no problems with shifting...go figure. Good luck and oh yes the campy 9spd will not work with the Shimano 9spd (wrong spacing).

jds108

A Shimano e-type FD might work, since they mount on the bottom bracket rather than the seat tube. I've never personally seen what kind of clearance they have right where your braze on mount is located however.

Here's what I'm talking about:

https://www.treefortbikes.com/497_333...Front-Der.html

HillRider

That won't help. A 44T big ring will still be too far below the lowest setting for the front derailleur. It doesn't matter what kind of crank arms they are mounted on, the ring diameter stays the same for the same tooth count.

dit

I have pretty much decided to use a Shimano road triple coupled with a 30 or 32 large cog, 8 or 9 speed cassette. This combo will give me lower gears than I am riding now so I see no problem there. Right now I am leaning towards staying with friction shifter but I am curious about brifters though I have never messed with them. S. Brown suggested a 113 bb axle for Shimano triple. The closest that I have found is 115mm in the price range that I am willing to spend now but I am still looking.

joejack951

Basically, the tradeoff is much improved ergonomics and faster shifting for more money and a little more setup and maintenance time. In my opinion, brifters are reliable enough that the average user won't be affected by their not-as-reliable-as-friction reliability.

Bottom bracket length will depend on which crankset you choose. Have you picked one out yet?

dit

I have not settled on a crankset yet but it will be my next purchase.

andr0id

For the interested. Braze on FD mounts used to have a 15mm slot and be centered for a standard crank. You could adjust from about a 52 up to a 55 or 56.

Newer FD braze ons are 20mm slots and some are centered to allow a compact or standard. Somewhere from about 48 teeth up to around 54 teeth.

This is one of those things where you mileage will vary.