Under BB cable routing steel - integrated

[druptight]

Curious if anyone has a steel rig with a brazed on tube under the BB that might be able to measure that tubing for me.

I just stripped the paint off my #1 and am either going to thread the hole on the BB to accept an M5 screw so that I can screw in the plastic guide OR I'm going to grab a length of steel tubing and braze that sucker on there.

I'm leaning towards option 2 right now, but I need to know the diameter of that tubing. I can find as small as .188 on the mcmaster carr website, but I'm curious if that's still huge since derailleur cables are so much smaller diameter than that. Anyone have this treatment on their bike that can take a quick measurement for me? Lots of web searching has yielded no results. Thinking something along these lines: http://photos1.blogger.com/blogger/2688/1006/1600/IMG_5682.jpg

Basically looking for the following 65 cent piece without having to pay $16 shipping for something that costs 65 cents: http://www.cycle-frames.com/bicycle-frame-tubing/STEEL-UNDER-BB-GUIDE.html

[Davist]

Here's one that may work at Amazon for ~$4 (free shipping)

http://ecx.images-amazon.com/images/I/41LXYTX0bBL._SX355_.jpg

http://www.amazon.com/Shimano-SP-18-T-Bottom-Bracket-Cable/dp/B0029LIY1A

EDIT: Sorry misread, thought you were looking for the plastic version

[C. Matthews]

Use a V brake noodle. It's stainless and the perfect size to use with or without a liner.

[m_sasso]

The local hobbies shop in my neighborhood stocks various types and sizes of small gauge tubing commonly used for projects from slot car chassis to fuel tank construction, check yours.

[druptight]

Use a V brake noodle. It's stainless and the perfect size to use with or without a liner.

Good thought - I may have one lying around. It may be aluminum though.

The local hobbies shop in my neighborhood stocks various types and sizes of small gauge tubing commonly used for projects from slot car chassis to fuel tank construction, check yours.

Another good thought. I'll look into this as well.

[thwart]

There's something about having long narrow brazed-in tunnels at the wettest, messiest part of your bike...

If you're dead set against a standard nylon cable guide, what seems to work fairly well is having brazed-on metal guides, and running cable liners in 'em...

[FlashUNC]

Good thought - I may have one lying around. It may be aluminum though.



Another good thought. I'll look into this as well.

I have used the V-brake tube option. Works really well.

[druptight]

There's something about having long narrow brazed-in tunnels at the wettest, messiest part of your bike...

If you're dead set against a standard nylon cable guide, what seems to work fairly well is having brazed-on metal guides, and running cable liners in 'em...

Those just look like tubes with the tops cut off or are they not rounded? I likely wouldn't leave the tubes closed off - I'd just leave a loop of the tube in tact near the entrance and exit and file off the "lid" in between most likely. Brazing just guides on adds in additional intricacies of sourcing a piece of steel the right size, somehow bending it correctly, then holding those tiny thin bits in place while brazing.

Tube tends to bend easy and has way more surface area to play with for holding it in place while brazing. Then you can file off the bits you don't want.

Alternatively, I've got the brass tubing I used for the internal top tube routing that a piece of housing fits through nicely - could use a halfpipe of that and then a piece of housing like you are using here - but it's pretty thin walled and maybe too malleable.

[numbskull]

I have a beater Basso that uses tubes. They are 5mm (.20") in diameter and covered for 5mm on each end. They are about 3.75cm long (measured along their circumference).

[numbskull]

Here is a more elegant way you might consider if you plan to repaint.

[druptight]

I have a beater Basso that uses tubes. They are 5mm (.20") in diameter and covered for 5mm on each end. They are about 3.75cm long (measured along their circumference).

Perfect, thank you!

[oldpotatoe]

Curious if anyone has a steel rig with a brazed on tube under the BB that might be able to measure that tubing for me.

I just stripped the paint off my #1 and am either going to thread the hole on the BB to accept an M5 screw so that I can screw in the plastic guide OR I'm going to grab a length of steel tubing and braze that sucker on there.

I'm leaning towards option 2 right now, but I need to know the diameter of that tubing. I can find as small as .188 on the mcmaster carr website, but I'm curious if that's still huge since derailleur cables are so much smaller diameter than that. Anyone have this treatment on their bike that can take a quick measurement for me? Lots of web searching has yielded no results. Thinking something along these lines: http://photos1.blogger.com/blogger/2688/1006/1600/IMG_5682.jpg

Basically looking for the following 65 cent piece without having to pay $16 shipping for something that costs 65 cents: http://www.cycle-frames.com/bicycle-frame-tubing/STEEL-UNDER-BB-GUIDE.html

Index shifting? Drill and install a plastic BB guide. Any metal on metal will have an impact on index shift performance. Plus tubes always seem to fill with gunk, effecting it more.
Friction? What ever is easiest.

[Peter P.]

http://ecx.images-amazon.com/images/I/41LXYTX0bBL._SX355_.jpg

http://www.amazon.com/Shimano-SP-18-T-Bottom-Bracket-Cable/dp/B0029LIY1A


Quiz question-What's wrong with that cable guide?

[dave thompson]

Image reversed.

[thwart]

Quiz question-What's wrong with that cable guide?
Screw designed for bamboo bike...

[thirdgenbird]

Screw designed for bamboo bike...

x2

[abalone]

Here is a more elegant way you might consider if you plan to repaint.


That's how they used to do it back in like the 70s. Do they even see derailler housing like that anymore?

[fogrider]

Here is a more elegant way you might consider if you plan to repaint.

I had a Klein Mt. bike that had a tube that routed the up from the bb and it caught sand and over time, it broke the cable...adjusted the screws and rode home in the middle ring.

[druptight]

Tapped the BB for an M5, and will use the screw on bracket. Thanks for the feedback.

[thwart]

Tapped the BB for an M5, and will use the screw on bracket. Thanks for the feedback.
If there's an easy yet effective way to do something, that's usually the best bet.

The only downside I can think of off-hand is that it doesn't look 'custom'… :cool:

As long as you're working in that area and the bike is stripped, drilling a (separate) hole to drain any water that collects in the bottom bracket is a good idea, IMO.

[ultraman6970]

I would go with the plastic cable guide. The one on the picture or the campagnolo one in plastic that has a long extension for the FD cable.

Brazing stuff honestly takes too long compared with a darn hole and a screw. Besides after the brazing you have to paint again. But is your call OP.

[oldpotatoe]

Tapped the BB for an M5, and will use the screw on bracket. Thanks for the feedback.

Good idea. I have done this for many older, below BB run cables, frames. It just works better. Sometimes removing old knackered tubes or grinding off guides, but function was the goal. On beautiful, essentially NOS or period correct frames? Maybe not but for most..great solution.