March 2, 2017
Of all the TPW Brompton upgrade parts we now offer, certainly the most functionally ambitious, dare we say exciting, is a kit to add a third rear cog to the drivetrain. A 6-speed Brompton becomes a 9-speed, while lightweight 2-speeds can become 3s, actually losing weight in the bargain thanks to titanium.
While >95% of customers find Brompton's stock 6-speed gearing adequate, people riding in steep hilly areas, especially loaded tourists, know that a Brompton's factory-lowest low gear is (a) not always low enough and (b) entails accepting quite a low top gear. TPW's triple cog kit extends a 6-speed Brompton's gear range from 302% to either 368 or 390%, extending the high and low gears alike. The difference between stock 6 and TPW 9 is comparable to the difference between Shimano's popular Alfine 8 and 11 gearhubs. (Brompton's is lighter and more efficient than either of those, but with coarser steps).
For example, using a 44T chainring (Brompton's "reduced gearing" option), the low gear can drop from 28 to 23 gear inches, while the high bumps from 85 to 92. Does this sound like modest gain? It is, but honestly it's just enough in my opinion. A broader range can be had at much higher expense and weight, but I'm hard pressed to conceive of many real-world scenarios where a much broader spread is worthwhile.
I've been running this new sauce on my Brompton for the last couple weeks of foul weather, so not much, but still enough to know it's a keeper. Around town, I have no need for the bottom gears even without this upgrade, but I do appreciate the higher top end already. I plan a 400-mile loaded hilly tour over Spring Break: that will prove things.
This modification has been a semi-legendary hack am...Continue reading...
We rent Brompton folding bikes, and sometimes a few other kinds. Bikes come complete with lights, locks, fenders, ample luggage options, etc. Bells are mandatory, no exceptions.
Part of our purpose in offering rentals is to let prospective buyers try our unusual bikes over longer periods. If you buy a bike similar to your rental within a week of return, we refund up to a week's rental fee toward the purchase.
Expert mechanics service what we sell in our four-stand workshop, and also offer general tune-ups, repair, and consultation on all kinds of bicycles. Schedule online or call for an appointment.
We specialize in modern internal hub gearing, generator lighting, and modifications for greater comfort and utility.
We are Portland’s first and largest bicycle shop devoted entirely to bicycles as primary transportation, serving urban households like ours seeking to avoid dependence on cars with practical, stylish bikes for everyday use: not just “commuting” bikes, but family transport, cargo, and folding bikes, all equipped for comfort, safety, and reliability. We also sell street clothing and accessories that support a practical biking lifestyle in all seasons.
We are not motivated by the rising costs of motoring, ecological guilt, or a body-sculpting regimen. Bicycling is not a sacrifice or a statement. We ride instead of drive because it is pleasurable and convenient, simply the best way to get around Portland. We do not sell sporting goods or fitness equipment: fitness happens by riding your bike right past the gym in the course of your normal errands.
We opened in June 2007, after our two families became partners to help make Portland an even better place to live and work, slow down in, ride every day. In a town with 70 other bike shops, we expanded our family-friendly shop three times through the recession to 7000 square feet, and in 2012 were named Best Urban Bike Shop in the United States by Bicycle Retailer and Industry News.