Sunday, August 30, 2015

Tsunoda Grand Prix: The Japanese Randonneur

One of the pleasures of working with old bicycles is that you can't stop wondering what the two wheeled machine was going through. The miles it was collecting, the conversations it overheard, and many a self revelation achieved after a long, meditative hours on the saddle. There are bicycles that needs a thorough make over after going through a lot of things over the decades, and then there are the ones that you simply glanced over and immediately thought, "Nope. Let's leave it this way."

The later situation could be said about this particular bicycle, making it able to be classified as a resto-mod project. This bicycle was bought secondhand at a real good bargain—meaning that everything you see here: the fenders, racks, components, and all are already on the bicycle when the owner laid his hands on it.

This Tsunoda Grand Prix Model E came from an era where many Japanese cyclists are obsessed with bicycle travel during the late '70s. You'll notice that this bicycle was highly influenced by the French randonneur bicycles. Since this discipline of bicycling demands extra hauling capability, the frame was designed to accept front and rear racks—hence the threaded mounts found on the middle of the seatstays and the fork blades. Triple triangle design, the kind you commonly found on GT bicycles, is adopted to achieve extra strength on the seat cluster area due to the extra contact area between the Tange Champion tube sections. Another distinctive feature is the built-in dynamo mount on the left seatstay, complete with internal cable routing through the downtube to supply power for the front fender mounted headlight. You can also spot the French influence at the 650B wheels with plump, cushy tires that dictates the use of cantilever brakes.

While we're on the subject of 650B wheels, there's a story behind it. The owner called to ask me about the odd "26 x 1 1/2" label on the tires before he bought the bicycle. The seller told him that it was not the 26" MTB size that we all known. Thinking it must be the ETRTO 590mm wheels, I told him to go for the purchase, knowing that we will be able to replace the rotten tires with something from Japanese city bicycles that were easily found here. Turns out that what people used to call 26 x 1 1/2 tires are what we call 650 x 40B today, or more recently, 27.5 x 1.5".
So if you thought that 27.5" slick tires are new inventions, they're actually weren't. They've been with us for a long time, labeled as something else. We ended up replacing the tires with a pair of reliable Schwalbe Marathons.

One tire, four size designations. 26 x 1 1/2 or 650 x 42B or 27.5 x 1.65, the ETRTO sizing is the same, 44-584.
Moving on to the components selection and the French connection became more and more apparent. The brakes we previously talked about are made by Mafac, the Cyclomoteur model to be exact. Although those are the only French-by-origin components installed the theme doesn't stop there. You see, other than the brakes the bicycle was built mainly with Japanese components: Shimano brake levers and hubs, Suntour downtube shifters and VX derailers, down to the Araya single-wall rims and Kyokuto pedals. But the Sugino crankset is clearly carrying the French theme with its TA Specialties-inspired chainring bolt pattern, along with the halfstep-plus-granny gearing combination.

These extension levers are originally designed by Dia Compe back in the '70s.
48/45/33T chainrings. Talk about weird combinations.

From the beginning we decided to keep the bicycle almost the way it was, only with some refinements to suit the new owner's needs. Other than a pair of new tires, the worn-out, hardened brakepads are replaced with Velo Orange threadless post cartridge-style pads, enabling them to work with modern road-style brakepad inserts while significantly increasing the braking performance. The rear wheel is redished because the owner wanted to fit 8-speed freewheel on it, making the gearing range wider without tampering with the rear dropout spacing. The cables and chain are replaced, too. The missing headlight is replaced, accompanied with new electric wires inside the frame. We add double kickstand too, because loading panniers with side stand could be cumbersome.

Lo and behold. Lights.
We moved the non-drive side hub washers to the drive side and retrued the wheel to squeeze three more gears.
13-32T 8-speed freewheel for extra oomph on the hills.

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