10 Speed Brompton Upgrade

The Brompton gearing upgrade kit arrived from Taiwan this morning and I've already built it into a new wheel, complete with a Tannus "No Flat" airless tire. The kit consists of a Sturmey Archer S-RF5(W) N 5x2 10 speed freewheel, 5 speed Sturmey Archer thumb shifter, two rear sprockets (12t & 17t) and hardware bits to put it all together. The finished product is fantastic with an additional 60% boost to the overall range of 362%. This adds two more higher gears for speed and another two lower climbing gears putting this Brompton in the running for an all-round 10 speed touring bike. The thumb shifter has a positive indexing and feels solid & comfortable, unlike the original Brompton plastic 3 speed. The whole kit went together quickly with only a few snafus. The first was the fact that my donor Brompton was a 2003 Model so it had a different dust cover on the hub. I had to shave down the back of the new Sturmey Archer dust cover to make room for two sprockets. I also had a bit of trouble fitting the 17 tooth cog. A 16 tooth would have fit without modification but the 17 was…

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Brompton Electric

It is August 21, 2017 and to celebrate the completion of our newest Brompton build, I rode out to view the total eclipse of the sun. While out riding I took a few photos of the finished bike. This build has all the features of the upcoming Brompton factory electric bike plus a couple of extras I deemed necessary for loaded touring applications. It has a 500 watt Crystalyte front hub motor capable of operating on a 36V or 48V battery so the torque power & speed is increased over the factory version. The UK has restrictions on the motor wattage and top speed of their e-bikes that we in the US territories do not have to abide by so I opted to use a motor with twice the wattage.  The controller for this motor is attached to the fork yoke by a lengthened fender (mud guard) bolt and does not interfere with the bicycle fold. [caption id="attachment_3907" align="alignright" width="300"] Crystalyte Hub Motor on Brompton E-bike[/caption] There is also a pair of Tannus (airless solid foam) tires on this bike as seen in this photo.  Note the lack of a valve stem.   It is important to emphasize how stress…

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