maunakea

The design goals were for a fast, multi-mode bike for Japanese cities that could also double as a touring bike for 3-4 day minshuku/onsen weekends. Onsen (Japanese hot spring) means mountains, or at least some significant hills. 70% of Japan is mountainous, i.e., the mountains start where the Sprawl ends (except on Hokkaido). I wanted a triple 11/34, ISO 622 wheels, and light weight (most subway and train stations in Japan do not have elevators). The packing regimen would be a QR rack with trunk and ATB panniers. Climbing stairs would mean bike over one shoulder, rack system with a shoulder strap over the other shoulder. Stairs to a pedestrian overpass is the most common rail station layout in rural Japan. Only in the boonies ("inaka") does one simply walk across the tracks to an opposite platform.

To meet the design goals, I have rebuilt a Dahon Cadenza (see pix), keeping only the frame, RD hanger, and seatpost. My comments are organized as follows: (1) the stock bike, and (2) the materials and methods used to rebuild the M.K'denza.

The Stock Bike
… is a disappointment, even for sub-$500 Dahon. The substandard (even for “Made in China”) factory packing was fatal to the ability to ride the bike out of the box. Instead of unbox, lock the maintube hinge, slide the stem on the steerer tube sleeve, tighten stem bolts, and ride away (the tires come inflated, the (platform) pedals are mounted), not that I would take such risk, I discovered about a 3 cm lateral variation from midline over a 15 cm arc of the rear wheel.. The bike was packed with the left crank arm wedged against the inflated rear tire … several months of pressure had deformed the rim to the point that it could not be trued. Retruing such a whacked rim, with resultant overtensioned spokes, may be the cause of several reports of spoke breakage in Cadenzas. The shipping box had one entire corner ripped open, the entire height of the box, copper staples and all, held together only by the packing tape that the seller (Sunshine) had applied. In addition to the tacoed rear wheels, both skewers had deep gouges from compression and rubbing. I called Sunshine, who got Dahon USA to ship a new rear wheel and two new skewers to me. I learned that the shipping damage to the 26” folders is so common that Dahon is supposed to start packing the big folders like they do 20” folders (wheels off) in the immediate future. Other shortcomings of the stock bike: the non-drive side bottom bracket cup is PLASTIC; the fork crown race appears to be plastic: the headset bearings are loose ball bearings in “China grease” (does Dahon really save that much using grade Z grease?); and, saving the worst for last, the “steerer tube clamp” doesn’t exist… there isn’t one…. folks, the star nut bolt (aka top cap bolt) is the ONLY thing keeping the fork in the headtube. The “adjustable height stem” feature of the Cadenza means the use of a compression sleeve the full height of the steerer tube, from the top bearings cap to the star-nut cap. Tightening the OE stem clamp compresses the sleeve which in turn grips the steerer tube. I feel more secure with a hacked stem as a steerer tube clamp, a la Swift and the Mauna Kea DTFS. The nearest description of the ride of the Cadenza, with the replacement rear wheel mounted, is “like a skateboard”. The straight steel fork transmits ever nuance of the road surface to your hands and butt.

The M.K’denza.
From front to back: Cane Creeek time trial brakes on a NB TT bar (oversize clamp area), NB inline brakes, and NB Jail Brake in the front and long reach in the rear. All new brake housing and cable. Shifters are Shimano R440, and therein lies a story: I managed to mount the "flat bar" R440 MTB shifters on a road bar… by chamfering the ends of the TT bars, lubing the surface of the bar with Mobile 1 synthetic, and GENTLY working the shifter clamp down the bar. I dremeled the bolt hole to ovalize the forward portion of the shifter clamp to allow the new, longer bolt (M6 1mm pitch) to engage. I also ovalized the inline brake bolt (M5 1 mm pitch) holes. The stem is a NB adjustable set for max inclination. My backup plan for shifters was barend shifters, but they tend to stab and poke other persons when doing the multimode dance.... not a good way to endear bicyclists to the general public.

I wanted to lengthen the cockpit as much as possible, have a sightseeing bar height for poking along, and a stretched out low position for speed. The OE loose bearings and cheapo cups were replaced by a Cane Creek S2. Note that there are MANY different “integrated headset” specs (Cane Creek itself as 3 different diameters). The S2 (or S6, SS ball bearings) presses in perfectly after the OE cups come out. Oh yeah … the OE headset is not truly integrated, just recessed.

The biggest ride quality improvement was mounting CF forks (NB). The difference in ride quality is astonishing, turning the skateboard ride into something close to my Merckx Majestic Ti road bike. This would be my most highly recommended mod to the Cadenza.

Another lucky break is the 68x113.5 bottom bracket sizing. I dropped an Ultegra BB in and mounted an Ultegra triple (52/40/30), with Shimano 9 speed chain and a SRAM gold link, SRAM 11/34 cassette, new cable housing and Teflon coated cable.

Now, the hairpulling part of the mod, the FD. MTB indexed RD shifters and RDs are interchangeable with road equivalents, but FDs are not. MTB indexed FD shifters and road FDs and road cranks “are not supposed to work”. Even though the Shimano RR440 is supposed to be a road shifter for flat bars, it had a shorter lateral range than a true road FD shifter. With patience, I got the FD to work on all three chain rings. The FD placement on the seattube and starting tension on the FD cable are DELICATE, and that’s an understatement. Positioning must be within 0.5 mm, and it is not the stock Shimano spec. Using the OE jockey wheel that changes FD cable uppull to downpull was not an option. The combination of the position of the OE cable stop (too high on the seattube, forcing a ridiculously sharp bend in the FD cable) and the bearing-less, bushing-less, plastic jockey wheel, meant that the FD would not shift to the 52 ring. I borrowed the cable routing and McGyver cable stop from the MK DTFS rebuild, and was able to deliver enough pull to shift to the 52 ring.

Once again, the “paint job” is truck bedliner, for two reasons: the bike takes hits in multimode, and I like the beater look as a theft deterrent.

The second most challenging part (after the FD setup) was the rear brake. Getting wheels was one of the easy steps… 29er cyclecross wheels, caught in a NB promo. The cyclecross wheels gave me the 135 mm OLN width. You can’t cold-set aluminum, it breaks. The rear brake mounting requiring dremeling out the mounting hole only on the forward side… which made access difficult, but with patience and a good burr, produced the hole needed.

The rebuild eliminates the cheap plastic parts (e.g., non-drive side BB cup, fork crown race), gets rid of a weak-rimmed wheelset, lengthens the cockpit to 27 inches from seatpost to bar (c/c), and improves the ride, as said above, astonishingly. The bike rides better than the Dahon Allegro, and folds much more quickly.

The quick "train fold" is to unlock the maintube hinge, release the adjustable stem with a 5 mm hex key, let the bar drop, and put the bike in an El Bolso. An even more compact fold is available by loosening the stem so that it rotates around the steerer tube, but I haven't needed that yet. The CF compression spacers are on the bike for looks, since the hacked stem clamp keeps the headset tight with real stem loosened.