Inertial

At the moment I am converting to STI shifters and unfortunately I didn't take pictures of my bike before stripping the components.
My bike doesn't have a bottom bracket routing guide system and instead makes do with a cable guide clamp where there is a curved metal guide pointing straight back to the RD but strangely enough two circle brackets whose holes run parallel along the downtube.

I can't post images just yet but if you Google downtube cable guide clamp I'm sure you'll find what I'm talking about. It's not the one that clamps towards the front of the downtube but right by the bottom bracket.

Now I am confused by the routing to the front derailleur since it doesnt angle up into the bottom pull FD. I also lack the pictures to reference to how the bike was first set up.

Am I supposed to use some cable housing where after the wire passes through the circular guides? I can't imagine that the shift wire rubbing against the metal guides without some housing would be good for longevity.

non-fixie 

Difficult to judge without pics, but if your guide is like the Huret below, then yes, a piece of housing is assumed between the guide and the FD. The corresponding derailleurs had a housing stop as well.

JohnDThompson 

I suspect you have one of the clamp on cable guides designed to work with a high-normal front derailleur, which uses a short section of housing between the cable guide and the derailleur.

A picture would help clarify what you have. If you can't attach a picture to your message, try a link to a third party picture host site or an image of a similar guide someplace.

Inertial

Yes it does look like that but I didn't know the original derailleur had a housing stop. Seems like I went too modern since I installed a tiagra FD which doesn't have a stop. Thanks!

After some more searching, I did find a cable guide clamp that has two metal ramps with one angled up towards the FD.

Dunno if I want to order more things or if I should try to return the tiagra FD and just run the original suntour AR.

ridelikeaturtle

Exactly - I just ran a small piece of cable housing from the cable-stop, underneath the BB, and up toward the FD. The old-style FD had a cable-stop for the other end of the housing; but of course that's been replaced w/a modern FD so you don't need to run the housing all the way to it. It functions perfectly, though it may not be the most elegant-looking solution.

Inertial

I wish I knew this trick before I cut down my cable housings to length! What's giving the housing a positive stop in this though? I feel like the housing would move and tug all over the place

Aubergine 

The old derailleur would have the stop.

Vintage_Cyclist

You could always get a single cable stop.

McBTC

With that type of FD (with a spring in it?) isn't it common to have a bare wire coming up to the FD from a guide on the bottom of the BB?

ridelikeaturtle

Since I've run mine below the BB, the BB is limiting any movement when the cable is pulled. It's the same as running a bare cable beneath the BB through a guide and up to the FD; just in this case, there's no guide - the housing does that function.

ridelikeaturtle

Here's a photo of what I've done, maybe it can give you some ideas. (I know, my chain is filthy, but it is my "winter bike"!)

jj1091

Well that's just against ALL the rules. You're a rebel!

speedevil 

If you have the tools to remove the BB, you could drill and tap a hole for an under-the-BB cable guide. It should be a simple enough job but since it appears you have a housing "start" on the downtube, you may not want to do that.

How does the cable route for the rear derailleur? If you could run bare cable from the stop on the upper downtube all the way to the final "bend" switching to a cable guide might work for you.

One of the advantages of bare cable runs is that the friction compared to full housing is reduced, which can help with shifting.

Slightspeed

My old Raleigh had the frame mounted guides ground away by some fixie genius in a past life. I found this Campy dual guide, because I needed guides for both cables. I have seen single ones, too. On my Legnano I routed it like the red bike above, but the Suntour Cylone II FD on my Raleigh didn't have a guide stop. The upper guide is a Suntour item. It all works great, though it took me awhile to figure out the bottom guide. I tried all the above mentioned methods, this one worked the best for me. Only problem may be tube diameter if you have a more modern frame. Good luck.

dddd

On my Viscount winter trainer bike (outdoor training, mostly in bad weather), I ran the cable through the brazed-on cable housing stop and then simply ran the bare cable under the bb shell and up to a semi-modern front derailer which had no cable stop.
I used it this way for several years, and never experienced any cable issues. The front cable doesn't move all that often, so guide wear or cable fatigue never presented itself.

On this 1965 Schwinn, the lower cable housing stop had been broken off, so again I just ran the cable under the bb shell and up to the Allvit derailer which had the (now redundant) housing stop on it. Again, no issues to report, though eventually the cable wears through the frame paint. All clearly visible in this photo:

RobbieTunes

Necessity. Invention's mom.

RobbieTunes

Dude.


Green.

RobbieTunes

Dude.


Green.


Dude.

Slightspeed

I can't imagine ever running a bare cable against unprotected paint. At least put a housing over it. When reassembling my old Raleigh after a new paint job, each slip of the wrench left a scratch that cut like a knife on my own skin. There are are all kinds of ways to do cable routing without rubbing thru paint. See above examples. Anal about sctraches? Not really. I ride the hell out of my bikes, and scratches happen, but why encourage them? Another rider posted a photo of my Raleigh from a Pasadena vintage ride. I noticed 3 marks on the chain stay that I hadn't seen before. I was out in the garage at 10 o' clock, the night before the next ride with touch up paint. Anal? No, I just hate scratches.

jpaschall

So obvious, but so smart.