SlushBike Rear Shift Adapter

Here's a true rolling prototype, in fact the 2nd or 3rd version of a design I've been refining for years. This is a good time to discuss it, since it's about to be retired (from SlushBike, at least). The pictures are based on the same shot, but with two apparent zoom levels to orient you to where it is on the bike.

This piece connects my favorite shifter, the Campagnolo integrated brake-shift lever ("brifter" for short), to a Shimano rear derailleur. These parts are not supposed to connect, and even if they were, the brifter is 9-speed while the cassette is 8-speed. I designed and fabricated it myself, from 6061 aluminum alloy.



The function of this adapter is to make the derailleur perceive the cable movement that is correct for its design, but which is driven by the incompatible brifter. The derailleur works by deforming a triangle where one of the sides is a stretch of cable which is pulled in or allowed to pull out. So the adapter really just shifts one point of this triangle, the one where the cable attaches to the derailleur arm and moves the pulleys. Of the three versions I've made, this is the most adjustable, so it could adapt lots of different shifter/derailleur combinations. You can see that it has a long slot for its mounting bolt (the original cable fixing bolt), and this controls the radius of the adjustment. The whole adapter can be rotated around its mounting bolt, allowing the angle of the adjustment to be set. This combination permits quite flexible positioning of the new pivot point compared with the original one.


This adapter has served me well for years, but it will be obsoleted on this bike when I convert to the internal hub.

Toupe Trouble

For the last year I've been using the Specialized Toupe saddle on my good-weather/long-distance bike. Last year it proved quite comfy and lightweight. My only reservation was its name. When I picked it up at CycleLoft, I pronounced it "toop", but was corrected to "toupee". It's hard to think of a sillier name for a saddle.

This Spring I noticed that it had cracked in the obvious place, just outside the rear connection to the rail, where the thin shell is cantilevered. (Let's leave aside the implications for my riding style or weight.) I've never broken a saddle before by simply riding it. In fact, I'd been fighting a 'saddle comfort' issue for over a month when I found this, so I think it cost me some real inconvenience and even a medical test.

I discovered the crack just days before the ride to Brewster, so I needed a saddle fast and was reluctant to risk buying a different, less comfortable one, so I picked up another Toupe. I had wanted to seek a warranty replacement, but couldn't find the original receipt nor the date I bought it, so I mostly gave up hope of that. But the Cycleloft salesman told me to bring the old saddle by some time and they'd see what they could do.

With little hope I eventually found time to return with the old saddle and the receipt for the new one. They looked up the original purchase date, printed a new receipt for it, and gave me a full store credit for the broken saddle! If I'd brought the saddle originally, they'd have given me the new one outright. I think that's the best return service I've ever had. I asked whether the new saddle would fail next Spring, and was told that if it does I'll get another new one. While I'd rather have a reliable saddle (I'll hold out hope that Specialized has fixed the design), I give Cycleloft my Local Bike Shop of the Month award!

Internally Geared Hub Daydream

Looks tempting, doesn't it?

Why are cars so good in bad weather? Their drivetrains are shielded from all the gritty muck on the streets. Most bike drivetrains are fully exposed, so one winter ride can make a mess of the whole thing. And gritty, rusty chains make for slow riding and high wear. Putting the gears inside the hub solves part of the problem. More important is shielding the brake, in the foreground of this picture. I'm still toying with the idea of converting SlushBike to use one of these.

[The picture is probably a Shimano Nexus 7 with standard brake. I'm really looking at the Nexus 8 with the upgraded brake. The roller brakes apparently burn their grease if overloaded, and for a small cost increase you can get a big heat sink on the thing.]

Brewster Fauna

This is another look back at Memorial Day weekend. I finally got some pix for you.

Why go to the Cape at all? Well, the kids have a great time, just like the adults. Here is E and his friend K, laughing it up at the beach. (Like all pictures here, you can click on it for a modestly larger view. If you want full resolution, let me know.) Let me confess this shot was a staged a bit to help capture the real fun they had all the rest of the time. We won't get into why they're laughing at me.

Last year I discovered that horseshoe crabs mate off the beach here. I was pulling up crabs as they raced by, to show to K and E. I found a monster one and started pulling it up. Then I realized that it had an extra body segment and put it back down. I had a guess, and later confirmed that this was a mating pair. The smaller male has specialized legs to grasp the female, and they apparently run around like that for a while. This year, on a sandbar at low tide, I saw a number of crabs like the one here. At first I feared they were dead, perhaps a post-mating die-off, like drone bees? Then I realized the crabs were pairs, with the female (wisely) dug into the sand, and they were apparently in good health. The male tail would swing around if provoked. I guess they were just caught by the tide, dug in, and will run around again when the tide turns. They really seem prehistoric! For scale, my (wide flat) size 10 footprint is in the foreground. Notice the bird footprints; I think they were really after the passengers on the crabs, not the pair itself.

I'll end with two shots of my bike as I rode it there. You can see how clean the bike trail was - a normal rainy road ride (like today's commute) makes the bike really dirty. The last pic is my crowded "dashboard" for the rare solo night ride on unfamiliar roads. From left to right: GPS navigator, main headlight, cadence/distance/speedometer, blinky/redundant front light, and heart rate monitor on the bottom [stem]. No more gadgets until I grow wider shoulders! [Road handlebar width is supposed to match shoulder width.]

Memorial Day Ride

We spent Memorial day weekend in Brewster, on Cape Cod. A&E went there Thursday and I followed Friday afternoon. I biked there from home, via the high-speed ferry.

Home to the Boston Harbor ferry terminal took only an hour of pedalling, but wall clock time was longer because of the many stops in Cambridge and Boston. This was only my second ride into Boston, and it felt empowering. I rarely drive into the city, and still feel intimidated by the prospect, so biking in feels like a real accomplishment. At the same time, the bike paths and lanes help make the trip safe, and the small scale of the city makes biking a very reasonable way to get between points. This leg of the ride had summery weather, but my jersey pockets had another layer in case of rain.

The ferry steamed toward the right edge of a rain cloud, but I had hopes of missing it until we pulled into the Provincetown channel and into patter against the windshield. The sun set as we docked; I turned on my winter headlight before starting off. The rain continued for the ~30 miles to Brewster though it tapered and sometimes paused.

My friend TMC recommended Gu as a mountain bike energy food. I rarely use one on the road, but I ate one just before I got onto the main highway for the next ten miles. A moment later I was struck that Route 6's shoulder was a great surface to ride, smooth and clean, and at the same time the rain stopped. Amazing what a little caffeinated glucose polymer can do!

From Route 6 I jumped onto the Cape Cod Rail Trail, this section new since last Memorial Day. What a nice path! Fresh, smooth pavement took me directly to my destination, in contrast to last year's highway ride on bad pavement and through an ugly rotary. I didn't see a soul on the path, freeing me from my concern that my headlight could be too bright for oncoming traffic. Better yet, the warm wet pavement created a ribbon of "sea smoke" fog over the trail, bracketed by fog-free grass. The headlight played up the fog for a dreamy ride. I reached A&E at ~9:10, earlier than I expected.

This was really a great ride. I cringe when I consider the alternative of trying to drive there in rush hour.

Phoenix & Rattlesnake

I'm tuned into a new news feed this week, on the Phoenix Mars Lander. Each sol is a new adventure. [Phoenix is a Nasa robotic probe recently landed near Mars' north pole where water ice is believed to lie inches below the surface. A small backhoe will dig into the red planet and an onboard lab will analyze eight soil samples.]

Mountain biked at Rattlesnake this morning, studying trails that I've forgotten and the new one. That place is crazy - way too hard, but fun and it continues to call to me. Tried boosting the negative pressure on the fork to make it softer on rocky descents, and it seemed better. Currently 115 positive and 125 negative; will try 130 neg next. (Default is matched positive and negative, and that's how I was riding before today.)