Bicycle Mechanics - No cable guides/bosses - what to do?

Hey guys/gals,

Another question regarding the bike I'm intending to build on an old Panasonic frame I've got lying around. There are no cable guides/bosses on the downtube, and no hole for which to screw on a cable guide underneath the bottom bracket shell. So in a case like this, what to you do for cable routing? Just put housing around the whole length of cable and tape it to the frame? I'd appreciate any tips.

Thanks!
-Fonk

Does it have boles in the tubes for which to run the casing? My old MTB from days gone by required the cable casing to run through the tube. You could always go singlespeed ;)

If that's not your style, I suppose one solid length of cable casing would do it. Does it at least have cable bosses where the FD and RD would go? If it doesn't, good luck getting it to work without brazing something on to hold the ends in place.

suntour clamp on cable guide, on ebay now:

http://i84.photobucket.com/albums/k39/trsrehnt/DSC01249-1.jpg (http://cgi.ebay.com/SUNTOUR-clamp-on-Derailleur-CABLE-GUIDES-NEW-in-Pkg_W0QQitemZ280053631075QQihZ018QQcategoryZ58094QQssPageNameZWDVWQQrdZ1QQcmdZViewItem)

It has a boss for the RD, but not the front. I just took a look at the POS bike my wife clung onto from high school, and on hers the cables are all encased, and just zip-tied to the tubes. Classic... Maybe I'll just have to go that route.

I originally purchased this frame w/ the intent of building it up as a single-speed for my winter training/commuting. However, I injured my knee a few months ago (nothing cycling-related), and it's not 100% yet, and don't want to risk re-injuring it before it fully heals; and give that the last 3 miles of my ride home is a 1000 ft. climb, that'd be a real likely possibility w/ a SS/fixed. Thus I plan on just staying geared this winter, and go SS/fixed next year.

[QUOTE=coelcanth]suntour clamp on cable guide, on ebay now:QUOTE]

I think that's what I need. Thanks!

You can also easily drill a hole in the BB and tap it to hold the modern plastic cable-guides. Much cleaner looking and won't damage your paint like the clamp-on guides.

If you don't want to drill a hole. Just superglue the bb guide to the bottom of the frame.

There is nothing as elegant as a Campagnolo cable guide... a little work of art.

http://piledrivermedia.com/files/ebay/IMG_3303.jpg

Sounds like a good candidate for a fixed gear conversion to me!

If you don't want to drill a hole. Just superglue the bb guide to the bottom of the frame.

Have you done this? Does it work pretty well?

You can also easily drill a hole in the BB and tap it to hold the modern plastic cable-guides. Much cleaner looking and won't damage your paint like the clamp-on guides.

This is not going to work in many cases. A lot of these older bikes routed (via the clamp-on guides) the RD shifter cable over the top of the BB tube to a brazed on cable guide mounted on the top of the chain stay.
Most modern chain stays have that rear cable guide brazed on the bottom of the chain stay and expects the RD cable to come from the bottom of the BB tube.

You can't just run the RD cable from the bottom of the BB tube (from a modern plastic cable guide) to a chainstay cable guide that's mounted on the top of the chainstay. It won't work.

The first thing you need to do is see whether the chainstay cable guide is brazed on the top or the bottom of the chainstay. If it's on top, then you need to use the old style cable guides that clamp on to the down tube, like the SunTour or Campy shown above. There is also a Shimano clamp-on that is similar:

http://www.thethirdhand.com/index.cgi?d=single&c=Cable/Casing&sc=Clips/Stops/Guides&tc=Cable%20Guides&item_id=SH-6229110.1&id=30093644929

This is not going to work in many cases. A lot of these older bikes routed (via the clamp-on guides) the RD shifter cable over the top of the BB tube to a brazed on cable guide mounted on the top of the chain stay.


Yup, that's the case w/ mine. So I guess the drilling/super-glueing isn't going to work; I'll just have to go w/ the clamp.

So will there be problem w/ the fact that the front derailleur is a bottom-pull? As such, I kinda need to route it under the bottome bracket, don't I?

Have you done this? Does it work pretty well?

Yup. Works fine. Also note that even if the glue were completely missing, the curved bb guide would be held in place by cable tension. The cables moving along the bb guide don't have transmit enough force even without glue to budge the guide.

You do want to glue that down, that being said.

Yup, that's the case w/ mine. So I guess the drilling/super-glueing isn't going to work; I'll just have to go w/ the clamp.

So will there be problem w/ the fact that the front derailleur is a bottom-pull? As such, I kinda need to route it under the bottome bracket, don't I?

Most road front derailleurs of that vintage were bottom pull, so you have a pretty common configuration.
I have an early '80s Nishiki Century that I upgraded to 700C wheels and current components and cabling the new FD was a challenge. This was all discussed, in detail, in an earlier thread:

http://www.bikeforums.net/showthread.php?t=198030&highlight=Nishiki+FD

There was an extended discussion of a problem similar to yours and I think reading that thread might answer your questions. I posted up a bunch of pictures of my solution. I'm not going to re-hash that whole discussion. I hope there is something there that will help you. Good luck.

Yup, that's the case w/ mine. So I guess the drilling/super-glueing isn't going to work; I'll just have to go w/ the clamp.

So will there be problem w/ the fact that the front derailleur is a bottom-pull? As such, I kinda need to route it under the bottome bracket, don't I?


I was about to rebuttal this but cascade linked to the old thread where I already posted my solution - go read it.

Most road front derailleurs of that vintage were bottom pull, so you have a pretty common configuration.
I have an early '80s Nishiki Century that I upgraded to 700C wheels and current components and cabling the new FD was a challenge. This was all discussed, in detail, in an earlier thread:

http://www.bikeforums.net/showthread.php?t=198030&highlight=Nishiki+FD

There was an extended discussion of a problem similar to yours and I think reading that thread might answer your questions. I posted up a bunch of pictures of my solution. I'm not going to re-hash that whole discussion. I hope there is something there that will help you. Good luck.

That thread was EXACTLY what I needed. Excellent job w/ the pics and everything. Thanks!!!

There is nothing as elegant as a Campagnolo cable guide... a little work of art.

I now find myself searching for a use for that cable guide, just so I can buy it. That is sweet.