Bike Friday built this frame for us to showcase at tradeshows as
well as to offer to customers visiting our office wanting to test the Rohloff SPEEDHUB and Gates Carbon Drive drivetrain. Bike Friday hand builds each of their folding bikes to their customers’ specifications in their Eugene, Oregon workshop. They are the only U.S.-made folding bike-specific company, and they have built a devoted following for their craftsmanship and functional designs. Their goal of producing "bikes that fold" as opposed to "folding bikes" comes through in the handling of their bikes. We added a few special touches to make the bike stand out, including red anodized components and a custom build kit. The result is an ideal travel or commuter bike that is easy to fold up and pack into a suitcase or trunk of a car or take into an office or onto a subway train.
This bike is built around Bike Friday’s Silk frame, which was designed to work well with the Gates belt drive system. They offer the Silk frame setup for a variety of uses including road, touring, and commuting. Sliding dropouts adjust belt or chain tension, and 20 inch wheels are used as on most of Bike Friday's other models. The 20 inch wheels offer more comfort on bumpy roads and a more usable gear range than the 16 inch wheels they use on their commuter-specific Tikit model. The fold point for the rear end maintains the relationship between the crankset and the rear wheel so that the belt or chain will stay tensioned when folded. The frame folds vertically around the bottom bracket, which results in a quick and user-friendly folding process. When completely folded up, the bike will fit neatly into a suitcase for easy travel.
While Bike Friday was building the frame, we sent a few components to our local anodizer to match them to the red color of the Rohloff SPEEDHUB and Schmidt SON28 hubs: front sprocket, rims, headset cups, Rohloff external gear mechanism cable box, and shifter housing. Once we had the parts back from the anodizer, we laced up the wheels using Velocity’s 20” Aeroheat rims with Sapim spokes and
nipples for fairly light, strong and durability setup.
On most folding bikes, the shifting components are particularly susceptible
to being damaged. The rear derailleur is one of the most delicate components on any
bike, and can easily be bent or broken if it is bumped. On a folding bike in
particular, the rear derailleur sits close to the ground due to the small wheels and is also exposed to being hit by the handlebars or front wheel
during the folding process. It is also likely to be hit or damaged on a crowded
commuter train with people filing in and out past the bike on the ground.
Additionally, small-wheeled bikes often use much larger chainrings compared to larger-wheeled bikes to account for the effect that wheel size has on the gear development. Front derailleurs are shaped to shift the size chainrings found on 26" or 700c-wheeled bikes, not the larger sized rings needed to maintain the same gear development on smaller-wheeled bikes. As a result, the shifting is usually slower and less crisp than is usually expected.
The
Rohloff SPEEDHUB offers an optimal shifting system for a folding bike because the
shifting components are all protected inside the hubshell and no shifting
parts are exposed to being bent or damaged. It is also typically used only with one front chainring, so there is no impact on shifting precision by changing the ring size.
A conventional bike chain is also less-than-ideal on a
folding bike because you're often coming in contact with the greasy, messy chain during the folding, packing, and transport processes. A
Gates Carbon Drive belt requires no oil or grease, so your clothes and
hands stay clean. This also means that no maintenance is required on it. Additionally, since the belts do not stretch, you get a service life that is significantly longer than with a chain - minimum twice as long and up to ten times as long depending on usage conditions.
We chose a
variety of components that put the rider in a comfortable, ergonomic seating position. A custom Groovy Cycle Works Luv Handle handlebar with 45 degrees of backsweep mimics the natural
resting position of a rider’s hands, Ergon’s GC1 grips feature a wide palm rest to take pressure off of the hands, and Selle Anatomica’s Titanico leather
saddle is very comfortable right out of the box with or without padded shorts. We rounded out the component selection with Magura’s MT2 hydraulic brakes, which provide good stopping power and require minimal maintenance, and Schwalbe’s Big
Apple tires, which feature a flat-resistant casing and large air volume to absorb the bumps.
When we took this bike out for a test ride, it felt
very comfortable and handled much like a bike with larger wheels. It was hard for us to tell we were riding a
folding bike until we looked down at the frame, which is the litmus test for any good folding bike. If you’re interested in the
ideal folding commuter bike or would like to take this bike for a test ride,
please contact us.
Build details:
• Frame: Bike
Friday custom Silk
• Fork: Bike
Friday
• Headset: Cane
Creek Solo
• Stem: Controltech
• Handlebar:
Groovy Cycles Luv Handles
• Shifter: Rohloff
• Grips: Ergon
GC1
• Seatpost:
Thomson Elite
• Saddle: Selle
Anatomica Titanico
• Seat
Clamp: Bike Friday
• Front
Hub: Schmidt SON28
• Rear hub:
Rohloff SPEEDHUB 500/14
• Spokes: Sapim
Race
• Nipples: Sapim
Brass
• Rims: Velocity
Aeroheat 20”
• Tires: Schwalbe
Big Apple 20x2.0”
• Cranks: Middleburn
