operator

'87 bianchi here using downtube shifters. I can't seem to figure out how the front derailleur cable is routed. I flipped the bike upside down, doesn't seem to be any braze on guides nor do I see a place where I can stick on a plastic bottom bracket cable guide. Am I missing something here?

I don't have what this bianchi does

Moose

Your bike probably had one of these:


This one is for sale on ebay, I did a search for "derailleur guide" see it here

roadfix

Your photo shows exactly how the cable is routed. The cable guide is there, right on top of the BB shell. Am I missing something here?

Moose

His photo is of a different bike...to illustrate what he is missing. Read his post carefully.

operator

Ahhh ok, thanks!

Retro Grouch 

At one time I seem to remember Bianchi just not using a cable guide for the front derailleur on at least some bikes. The cable just ran under the bottom bracket shell and up between the chainstays. That's going back maybe 20 years or more so don't quote me as an expert source.

sydney

Not even a groove or set of holes to keep it in place?

Retro Grouch 

Nope, no groove on a new one anyway. The magazine article said they thought a groove would eventually be worn by the the derailleur cable but I think that it'd take a pretty long time. How often do you shift a front derailleur anyway?

cascade168

Wow, that's an amazing question, to say the least. I don't know where you ride, but here in New England straight and level is the exception. Most of the roads here have constantly changing grades and it's shift, shift, shift - front and rear. If you are trying for a steady cadence, the front derailleur is just as important as the rear. Do I shift the RD more often than the FD? Sure, I do. But I use the FD a lot.

sydney

Sounds bogus to me too.

operator

I thought about running the cable sans guide and then realized i'd eventually wear a groove and decided to spend the $10 on the guide

Rowan

Drill a hole in the BB shell, tap it for the appropriate metric bolt and screw on a plastic cable guide. Care with length of bolt, however, and angle of cable guide.

Oops, sorry, you'd better put down that drill and back away from that suggestion

Sydney, don't some old derailleurs have the cable stop built into them so the cable outer runs right up to them? I am sure I have at least one old derailleur at home like that.

Dumb question, too... the derailleur is not top pull instead of bottom pull?

operator

105 FD, it's bottom pull, or at least that's what it says...

sydney

correcto.Typically cheap bikes with stem shifters and shift casing that ran all the way to the derailer. He also needs to make sure there is a cable stop on the right chainstay for the RD. There are bolt ones.

Don Cook

If you want to install a plastic cable guide under your bottom bracket, then do it. The guides cost virtually nothing. Center punch a spot on your bottom bracket and get out your drill. Run a corect size tap into the hole and walla! You can now mount your cable guide. On an 80's vintage Benotto of mine the cable ran under the bottom bracket and against the painted surface. There was a brazed on metal guide that the cable went under. It didn't take long for the cable to wear through the paint and create a groove. Then the rust comes. Before having the frame refinished and powder coated, I removed the brazed on guide. After getting the frame back, I drilled and tapped the bottom bracket bracket to accept a plastic guide. These are bicycles, not space shuttles.

seely

My Paramount is set up the same way. Its just got a nice worn groove for the front.

Retro Grouch 

Well, I can see several alternatives:
1. Leave it the way that it is. I assume that the cable will eventually wear a groove, but I don't see the nylon cable guides wearing out very quickly so I assume that steel would last longer.

2. It is a steel bike isn't it? If it is, you can probably find a clamp-on cable guide that will fit the seat tube.

3. Drill and tap the bottom bracket for a nylon cable guide. If it was my bike, I think that's what I would do.

4. The quick and dirty but functional method. Slide a 4 inch section of cable housing over the shift cable. The tension of the cable against the bottom bracket will be adequate to hold it in place.