Bicycle silouhetted against balcony

A measure of progress

Today is warm and sunny — a perfect day for riding. Or maintenance.

Kuroko has been sitting unused in the Workshop in the Sky for a month now while I’ve been waiting for a good opportunity to take care of a few non-critical issues:

  • Since I upgraded to a Di2 rear derailleur, I’m not able to remove the rear wheel (at least without either fully deflating the tire or removing the derailleur).
  • I want to replace the grommets where the Di2 wire and hydraulic brake line pass through the frame.
  • Finally, I got a combined Garmin and GoPro mount to de-clutter the handlebars a bit.

Non-quick release

When I tried to disassemble Kuroko for the road trip to Hamanako, I wasn’t able to get the rear wheel free of the derailleur. I got the wheel out of the dropouts, but the cogs wouldn’t clear the derailleur’s jockey pulley. I tried moving the derailleur to a few different positions, and tugged on it by hand. I even played about with the clutch lever. Nothing worked — the wheel was pushed all the way forward until the tire pressed against the chainstays, but the cogs would not clear the jockey wheel.

I searched some of the forums and a number of people have reported this issue with Di2 derailleurs. One solution that occurred to me was an extension for the derailleur hanger. This would move the whole derailleur down a couple of centimeters, and probably create enough room to remove the wheel. But it might make it difficult to adjust the derailleur to be close enough for precise shifting, or even bring the idler wheel dangerously close to the ground. (It’s a very long derailleur cage.) At the very least, it would probably require me to add three or four links to the chain.

Detail of derailleur mounting with limiting tabs highlighted
Hacking the derailleur alignment

I got a derailleur hanger extension and was ready to install that today. But before doing that, I had another go at the derailleur mounting. In the picture above I’ve added some color to help illustrate. Originally the two limiting tabs on the derailleur (in blue) were straddling the positioning tab on the derailleur hanger (in red). I took the derailleur off and remounted it so the derailleur’s limiting tabs are both above the hanger’s positioning tab — rotating the entire derailleur counter-clockwise (in the orientation shown; clockwise when viewed from the bicycle’s drive side).

This immediately gave me enough room to remove the rear wheel without having to deflate the tire or remove the derailleur. It also let me back down the B limit screw, which had been wound out nearly to its limit. Following that I readjusted the derailleur (with a quick check on the internet to remind myself how to do that), and ran it through all the gears. Like butter.

It’s almost as if this was the intended mounting position.

Grommet grief

The grommets are the big remaining finishing touch for the Di2 conversion. Kuroko came with cable-operate derailleurs and brakes. In that configuration, the brake cable passed into the downtube up near the headset, and exited just above the bottom bracket. The derailleur cable, meanwhile, ran alongside the downtube, externally.

With the Di2 upgrade came a switch to hydraulic brakes. And a single electrical cable takes the signal from both shifters to the junction box mounted under the bottom bracket from whence two cables emerge, one for each derailleur. With this configuration, I ran the hydraulic hose for the rear brake through the downtube, together with the single line for the Di2 shifting.

Which brings us to the grommets. Previously there had been a grommet at each of the openings in the downtube, with room for the brake cable only. I hacked the grommets up using a razor, and with a lot of effort I was able to get the upper grommet in place. Kind of. Mostly. On the bottom grommet I gave up after a number of efforts.

Then followed a lot of internet searches. I finally located a similar looking grommet from another bike manufacturer that has two holes and is readily available. So I was all set to give these a try today.

… or not. Installing the grommets will require me to unscrew the hydraulic fittings at either end of the rear brake hose, and that means replacing the fittings when it’s time to put it back together. At the start of today’s maintenance work I was gathering together all the bits and tools, and something was missing. There’s a piece missing for the tool to insert the hydraulic fittings into the hose ends.

I emptied the entire toolbox looking for that one little fitting, and came up empty. I found a set of tire levers, which means I’ve been commuting on Dionysus the past couple of weeks without them. I took a couple of minutes out from the maintenance to go down to the bicycle parking in the basement and put the levers in the saddlebag.

So the grommets await another day. I’ll keep looking for the fitting, and then perhaps the next rainy day, now that it’s warm, I’ll get back to it.

(Apologies for so many words with no pictures.)


Kuroko’s handlebars serve as attachment points for the:

  • headlight
  • bell
  • GPS unit (Garmin)
  • GoPro camera

It’s all quite tight. When I rewrapped the bars during the Di2 conversion, I tried to leave a bit more space. But the problem is the bars flatten out not far from the center, making them more comfortable for riding with my hands on the tops. The round portion that is usable for mounting has a limited width.

I’ve seen mounts for the GPS that attach to the front of the handlebar stem, so I decided to give one of those a try. I found a model that handles both the Garmin and the GoPro, and that was a sale.

The mounting hardware isn’t very sophisticated. (Nor am I — the first thing I did was drop one of the spacers in the balcony drain.) But it seems solid enough now that it’s together. My only concern is the camera and GPS together weigh a fair bit, putting a bit of torque on the attachment. We’ll have to see how it holds up. (Vibration shouldn’t be an issue as the camera already smooths the image.)

Because the handlebar stem is angled upwards, the Garmin ended up being tilted upwards. I hadn’t thought about that — it probably will not be an issue and it might even make it easier to see the display while I’m riding.

The mount does not permit attaching the Garmin’s external reserve battery. So for longer tours, I’ll have to revert the set-up.

Long overdue for a bath

With the day’s work done — the bits I could do — I gave Kuroko a long-overdue bath, followed by cleaning and oiling the chain. It was showing spots of rust after just a month laying fallow. Finally I pumped up the tires and replaced the bags and pump.

The forecast tomorrow is for warm and sunny weather. I haven’t yet decided a destination, but I’m sure to be out, puffing along somewhere.

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3 responses to “A measure of progress”

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