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External cable routing and fixation

Posted: Tue Aug 21, 2012 12:21 pm
by CrashBoomBang
Hi guys,

I am a silent reader for some time and got heaps of great ideas from this forum already. Thanks for that. I am currently converting a fixie into an internal gear hub commuting bike and everything is running smooth so far. I am about to build the wheels and then it comes down to the assembly. One thing I forgot to look into is the cable routing. The fixie frame is a very basic frame with no cable mounts or guides whatsoever. The original rear brake cable was attached with cable ties.

I am a bit concerned that without proper routing and fixation of the shifting cable I might run into shifting problems. My areas of concern are:
- cable fixation along the lower tube
- cable routing and fixation underneath the bottom bracket

Any ideas on this? Do you now of any aftermarket solutions that do not require welding parts onto the frame?

Cheers,
Andy

Re: External cable routing and fixation

Posted: Tue Aug 21, 2012 5:24 pm
by rustychisel
Anyone who deals with older bikes (ie old steel) and any good bike shop should be able to get their hands on clamp on cable guides which come in a range of designs and diameters. You'll need at least one for the downtube, a guide of some sort for the bottom bracket area, and a cable stop and guide for the rear chainstay.

Try to source some nice ones: DuraAce used to be very nice light and well chromed. For the bottom bracket area you could easily drill and tap a single hole on underside and screw in a modern plastic cable guide; that might be the most aesthetically pleasing.

As you probably found out, cable ties (zip ties) don't work well and just rub your paint off.

Re: External cable routing and fixation

Posted: Wed Aug 22, 2012 11:49 am
by CrashBoomBang
Thanks for pointing me in the right direction rustychisel. I will go with your suggestion on the drill & tap guide option for the bottom bracket. Regarding the cable stops & guides I am using aunti Google to find what I am looking for.

Re: External cable routing and fixation

Posted: Wed Aug 22, 2012 12:12 pm
by hazmat5765
Hi CBB, try Vintage Bicycle Rebuilds in Vic. (just google it.) for cable guides. Look at "Cable Accessories" & "Shifters/Parts", I have no affiliation with them but I have always found them reliable.
Good luck, Rob.

Re: External cable routing and fixation

Posted: Wed Aug 22, 2012 1:56 pm
by find_bruce
Which internal gear hub are you using ?

The reason I ask is that the Alfine 8 I have has a specific cable housing that is complete from the shifter to the cassette joint at the rear, so all you would need are cable clips, not cable stops or guides.

ie some of these
Image

Of course if you are using a different hub, this may not apply, but there are plenty of people here who have actual knowledge & would be able to help

Re: External cable routing and fixation

Posted: Wed Aug 22, 2012 9:24 pm
by CrashBoomBang
I got my hands on an Alfine 11-speed hub and it got the same continuous cable housing. If the clamps would suffice then that would make the build even easier and Rob has given me a place where I can get them.
Thanks heaps guys.

Re: External cable routing and fixation

Posted: Thu Aug 23, 2012 9:56 am
by find_bruce
You'll be sweet as with just the cable clips - the hub end of the cable clips into the cassette joint. The 11 speed is the longer one in this pic
Image

The other trick you might like to think about concerns the cable routing, which as you say is normally along the chain stay. This is determined by the non-turn washers, green & blue are for vertical drop outs, & silver & grey ones for horizontal drop outs. You can also get yellow & brown for Shallow Dropouts (20 ° or less) or Black & Gray for Shallow Dropouts (38 ° or less).

A neat trick is to use different non-turn washers so that the cassette joint runs up the seat stay instead - you can then run the shift cable along the top tube & down the seat stay. You may or may not get clearance issues. See for example this thread.

Re: External cable routing and fixation

Posted: Fri Aug 24, 2012 2:12 pm
by CrashBoomBang
Running the cable along the seat stay is indeed interesting. Instead of having cables running along the down tube and the top tube, I could run both the brake and shifter cable along the top tube. That would be especially nice because I am a bit "anal" about the design of the bike and having half the number of clamp-on cable guides would be nice to have.

However, I have further plans with the bike. Stage 2 of the build will be a conversion to a carbon-belt drive system. There are few problems with that conversion that need to be addressed such as braking the frame or finding the correct chain/belt line. The belt will also be wider than a chain, so I need to figure out how much clearance will be left between belt & seat stay and then belt & casette joint.

But, first things first. Fixie to internal gear hub bike. Once that is done and I can ride the bike, then I'll start further stages. My mid-life crisis is not over yet and I am a hands-on engineer with an office job. I need compensation :D

Re: External cable routing and fixation

Posted: Fri Aug 24, 2012 5:26 pm
by hazmat5765
CrashBoomBang wrote: My mid-life crisis is not over yet and I am a hands-on engineer with an office job. I need compensation :D
I understand that completely mate, go for it!
Rob.

Re: External cable routing and fixation

Posted: Fri Aug 24, 2012 8:57 pm
by find_bruce
In which case you will probably enjoy this thread on belt drives as well