Actually, I do have the external gear box. Never installed one of those before either. So what is the special caution in regard to the external gear box?
Hi Gene!
The primary caution is to make sure of your cable placement in/around the pulley of the external gearbox before tightening down the grub screws as the pressure of the grub screws can deform the cable, making it difficult to re-use the cable if one gets it wrong the first time.
As Rohloff's directions show, you need to cut the cables longer (total 200mm past the housing with the cable heads firmly bedded in their stops) than with the internal shifter.
Also, Rohloff recommend owners periodically lubricate the interface between the External Shift ("click") box and the shifting shaft. Since I often tour in America's Great Basin where I encounter talc-fine alkali dust, I decided to take things a step beyond Rohloff's specific recommendations and pump my External Clickbox full of Phil Wood grease to prevent internal corrosion. Time will tell if this was a good choice.
I also chose to apply anti-seize to the countersunk machine screws that hold the cover on the shiftbox, since this can be a point of corrosion. As suggested by Dave (expr), LocTite can also be used to prevent galvanic corrosion between the bright-zinc plated screws and the External click-box's aluminum cover and threads. Left dry, corrosion has been known to form around the threads, making future removal difficult or impossible.
A final caution with the External shift-box is to shift to Gear #1 or Gear #14 before removing the shiftbox and rear wheel. This simply eases reattachment, requiring only a little wiggle of the shift knob as you ease the shiftbox back in place and tighten the screw. If the shifter and box/shaft come out of registration, it is easy to fix -- simply turn the hub shaft fully one way or another using an 8mm box wrench, turn the shifter to match, and all will couple-up fine once again.
Some links you may find helpful are here:
• Photo and description of my grease-filling efforts:
http://www.thorncycles.co.uk/forums/index.php?topic=4523.msg36175#msg36175• Forum topic devoted to lubing the EX click-box:
http://www.thorncycles.co.uk/forums/index.php?topic=3325.0• Forum topic devoted to re-cabling a Rohloff external shifter:
http://www.thorncycles.co.uk/forums/index.php?topic=2676.0• Thorn's FAQ discussing the Rohloff internal and external shift cabling:
http://www.thorncycles.co.uk/rohloffcables.htmlThorn do not currently have a video showing how to replace an
external shift cable, but there are two videos from other sources:
• Rohoff's video showing how to re-cable the EX shifter:
https://www.youtube.com/watch?v=9_ha9__3VLg• Co-Motion Cycles' video showing their approach to re-cabling an EX Click-box:
https://www.youtube.com/watch?v=O3up1eZT3Pg• The Forum board most directly devoted to discussion of the Rohloff Speedhub is here:
http://www.thorncycles.co.uk/forums/index.php?board=25.0• I have also written a short tutorial on how to quickly and effectively search the Forum, available here:
http://www.thorncycles.co.uk/forums/index.php?topic=4390.0 This should help you easily find more on any topic discussed here.
Best,
Dan.