Hi All!
This afternoon turned out to be warm (60°F/15.5°C) and pleasantly sunny despite the forecasts, so I took the Nomad outside to make some progress on the rest of the light wiring. I removed the rear wheel and routed the taillight wire as I did on Sherpa, inside the left-side lip of the rear mudguard, through two Futaba R/C rubber grommets, and then employed a couple Dean's R/C #1225 gold-plated micro-connectors at each end so I can remove the rear 'guard or change to a different taillight in future with little fuss while leaving the rest of the wiring intact. I used a gel-type beta-cyanoacrylate and wooden clothespins to keep about 5cm of wire at a time under compression against the 'guard till the glue cured.
Unfortunately, I ran short of wire for the middle section and will need to buy more from Peter White. The Nomad's suspension-corrected frame design means there's a fair amount of space between front tire and downtube, and I want to span the gap by coiling the wire there to serve as a strain relief. Coiling takes up a fair amount of wire, leaving me just short for now.
While I had the Nomad on its side and the wheel out, I decided it was a good time to disassemble and thoroughly lube the EX (external) Rohloff shift-box, something I have pondered for some time. Given some past problems among Forum members with seized cover screws and cable problems, it seemed a good idea. I've had the bike about 6 months and didn't want to push my luck and encourage galling by leaving it alone past this point. I also wanted to make sure the unit was grease-sealed against the talc-like playa I will encounter in the desert.
I removed the two Torx screws that hold the cover plate and coated their threads with anti-seize. I then popped the cover and removed it and the pulley for the shift cable. Of course, the pulley is under some torsion, 'cos the cable wraps 'round it, but if you use care to keep tension on it, it may be removed laterally from the box with cables still in their raceways and the adjusters slide out as well with no change in tension.
While it was apart, I grabbed one of my cameras for some quick pics. The photos aren't not as crisp as usual 'cos I had one hand holding the spool under tension and the other hand had some greasy fingers I didn't want to transfer to the camera.
My shift box was innocent of any lubricant, and the
red arrow shows where the EX housing contacted the edge of the pulley, causing some friction when shifting and showing some contact with the pulley. I greased that face, then pumped the lot full of my preferred Phil Wood waterproof grease and bolted it back together, torquing the cover-plate screws to spec. Shifting feels much more fluid and shifting effort is slightly reduced. Though it is often overlooked, Rohloff do specifically recommend lubing the EX shift-box, as Andre has mentioned on several occasions:
http://www.thorncycles.co.uk/forums/index.php?topic=3325.0http://www.thorncycles.co.uk/forums/index.php?topic=5049.msg26349#msg26349http://coolmainpress.com/BICYCLINGRohloffEXTservice.htmlThere is a difference between what Andre and Rohloff have in mind and what I did today.
The Rohloff manual (here:
http://www.rohloff.de/uploads/media/Service_en.pdf pg. 3, photo 5) indicates, "To lubricate the cable pulley bearing, remove the cable box and place a little grease on the parts arrowed in the picture above". I considered this carefully, and on looking at the side of the pulley, there were signs of friction. Since grease could migrate into the box from the open face of the click-box, I decided to fill the box with grease and monitor it over time. If the worst should happen and it gums up, it won't be a huge thing to dunk it in the solvent tank, replace the cable, and be back where I was. Yes, I also realize it would make cable replacement messier, but still possible.
My touring conditions are a bit different from others', and the talc-fine corrosive alkali dust I go through can filter into everything. I am hoping the Phil Waterproof grease will form a barrier; it is the only grease that proved to hold up in my use against Mt. St Helens' corrosive volcanic ashfall when I rode through it in 1980. Phil grease has worked well for me in a number of sealed assemblies over the years and even when pumped into freewheels and cassettes for use in sub-zero F temps, and I am hoping it will also work well here. This is an Experiment -- for Science -- and will provide an opportunity to see how it works over time. I have several months before I my next big tour, and will have ample opportunity to discover any problems before I leave.
Some tips, if you give this a try:
• First shift into Gear 1 or 14 to prevent indexing problems on reassembly.
• Once the cover is removed, keep the cable winding spool under tension and remove it directly toward the open side. The adjustment barrels will slide out laterally as well. With care, no tension adjustment will be necessary on reassembly.
• With the box open and empty, clean out any debris and then manually lubricate the lip shown by the red arrow.
• While keeping tension on the winding spool, slide the lot directly sideways into the box. If the cable comes out of the raceway or crosses another, the cable will effectively be too short to allow the adjusters to seat on their 'box mounts. This is something you should check, as a crossed cable will make for rough shifting, poor adjustment, and short cable life.
• Once the contents are back in the box, pump in sufficient grease to level and a bit more. You want the excess to squish out when the cover is replaced, ensuring a full fill and grease seal from the inside-out. Wipe off any excess.
• Retorque the Torx fittings to spec, refit to the hub, and call it done.
A quick and easy job, it took me all of ten minutes including the photos. I'll report back later as to how it all works out.
Best,
Dan.