Tuesday, October 27, 2015

More Than Meets The Eye

Got to admit, classic exotic road bikes or high-tech full suspension mountain bikes are great, but nothing brought more people aboard bicycles than urban bicycles. You'll see more people riding folding bikes than, let's say, a pristine Colnago C40. Primarily used as means of first or last mile transportation—the trips between your departure point or destination to the nearest public transport station—a folding bike will let the rider carry it aboard the bus, train, taxi or whatever, which then allows even the people with the most mediocre athleticism to cover more miles.


A quick glance over the opening image above and you might think that it's just a stock 2010 Dahon Mu Uno. But looking at the cables tied to the frame, a question emerges: what's a pair of cables that went to the rear section of the bicycle got to do with the singlespeed, coaster brake-equipped Mu Uno?


The answer is because it's as stock as Marty McFly's DeLorean. The owner wanted to add more gearing ratio to this Mu Uno, while keeping the appearance as stock as possible.
First issue is to shove a 7-speed Shimano Nexus internally geared hub to to the 120mm-spaced Mu Uno frame. Although it was listed as a hub with 130mm over-locknut-dimension, removing the roller brake assembly brought the over-locknut-dimension down to 120mm. So, no big deal.


The problem arises when the owner insisted to use the stock rear rim, something a bit challenging since the stock rim have 28 spoke holes while the hub have 36. Sure, 36-holed ETRTO 406mm rim is easier to get, but we all like to add a bit of puzzle solving to our lives, right? Some research and an Excel worksheet later, correct spoke length(s!) were calculated, and the result is a symmetrical lacing combining 2-trailing 2-leading and crow's foot pattern.

Build a wheel with mismatched hole count, they said. It will be fun, they said.
8 different spoke lengths, 8 different tension numbers later.
Tada.
Rear wheel problem solved, but also brought another problem. With the absence of roller and coaster brake, we have to figure out another way to fit a rear brake. Enter the Eiosix brake adaptor that will allows us to install long-reach caliper brake at the kickstand mounting plate. Apparently the mounting plate dimension changed a bit when this 2010 Mu Uno was produced, but nothing a set of round files can't do.
While waiting for the front Tektro R365 to arrive, we have to settle with old Shimano single pivot caliper. Braking performance is good, but switching to double pivot caliper brake will improve it significantly.



To deal with tangling cables, manufacturers equip their folding bikes with some sort of a plastic ribbon that you can coil around the cables, keeping them together. We figured out a neater solution while negating the need of another cable mounting point behind the headtube. Apart from the cable ties holding the cables near the bottom bracket area, the bicycle looked almost factory. We topped this build with an aged Brooks B17 saddle.





The best part? Apart from the missing sidestand, the Mu Uno still folds like stock. While retaining its unassuming, understated look, this bicycle can transform at will, being the practical means of transportation it was intended to.



2 comments:

  1. kesan minimalisnya sedikit hilang. :)

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  2. Great project! Very interesting to see how the Nexus hub was fitted into the bike. This gives me an idea for a new project.

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