Mud flap

Dirt, water and leaves were being sprayed up by the Firefly wheel. Especially the wheelchair's flip-back footrest mechanism was catching a lot of wet debris. The picture shows some of the schmutz after it dried (a lot already fell off and made a mess at home).

So I super-glued and taped a rubber sheet (cut to L x W: 5.25" x 5", 1/16" thick) to the fender. The mudflap is effective, and after many trips with plenty of wet leaves, nothing new has stuck to the footplate.  It reduces the open tire aperture to less than 1 inch from about 3.5 inches.  Because the material is flexible, ground-contact is not a problem.  In the photo, the bottom of the tape (2" wide Polyken) corresponds to the fender bottom. 

2/19/2019 Update: The link at the top shows pictures with a mudflap. So the manufacturer has either added one since mine was made, or removed it since the photos were taken.

Headlight location

Days have gotten shorter, and how should we pierce the inky blackness?  With a headlight of course, which the Firefly's designers helpfully included.  But the original location, so close to the ground was not ideal, and the battery above forced a near horizontal beam direction.  The shallow angle illuminated the ground in front poorly, and rudely shone up into people's faces.  For illumination and civility, it's better to place the light higher up and direct it downward.

Placing the Firefly's lamp higher, required disconnecting its HIGO connector and unscrewing from the mount.  Then I cut the cable halfway between connector and lamp, to splice in a few feet of extension (without crossing the wires).  Finally, I took an attachment clamp from an old bike reflector, to mount the lamp higher on the steerer tube.  Now the light is still weak and oddly blue, but it makes a useful bright spot, and shouldn't bother passersby.  The old light location is a good spot for a front reflector.

Tools and supplies needed:

• Old bike reflector
• Old USB cable for extension
• Wire cutter / stripper
• Soldering iron
• Heat shrink
• Electrical tape
• Phillips #2 screwdriver

September, 2020 update: At some point, I removed the stock headlight and have been relying on a handlebar-mounted Cateye AMPP800.  It is important to point the light downwards, to avoid blinding oncoming pedestrians.

Tire change

After 1000 km, the original tire (ETRTO size 47-203) was getting bald (not the only thing doing that), and it was time for a replacement.  The new tire is a Schwalbe "Big Apple", size 50-203.  The Schwalbe tire went onto the rim by hand and seems like a quality product.  The original was really tight and I used steel motorcycle tire levers to remove it.  Unfortunately I scratched the inner rim and didn't think of sanding down any sharpness before putting on the new tire.  Hopefully this doesn't cause a flat.

After loosening the outer wheel nuts, the axle had a 5 mm or so total gap between the inner wheel nuts and fork legs.  A pair of washers whose thickness matched the gap had been put on the outside of the fork, and the fork legs were being bent to close the gap.  Putting the washers on the inside allows the wheel to be mounted without bending the fork.

The V-brake needed adjustment to match the new wheel position.  Making this adjustment had the benefit of significantly reducing brake shudder.

PS: For reference, the inner fork spacing is 5.375" (137 mm).

1000 km

Other numbers:

• 99 hours, 42 minutes (total time)
• 10.1 km/h (average speed)
• 202 days (ownership)
• Several hundred trips enabled by the Firefly
• Dozens of friendly compliments
• 1 significant mechanical issue:
• Shims for the wheelchair attachment are slippery.  If used, inspect them regularly.
• 1 tip over accident
• while going around an illegally parked truck.  Always cross drop-offs at a perpendicular angle, even when annoyed.
• 1 worn out front tire
• 1 flat rear tire (from a thumb tack)
• 0 collisions
• 0 empty batteries

Need for speed

Speed kills, but it also thrills.  The converse is also true:  Slow is safe, but oh-so-frustrating.  My manual wheelchair travels slowly because steering is problematic, shoulder power is limited, and obstacles abound.  Amazingly, the Firefly electric front wheel attachment solves these problems.  Power at the wheel is up to 350 Watts, similar to a professional bicyclist and over 10 times more than most people can get out of their shoulders.  The handlebar allows for proper steering, and the longer wheelbase improves handling on non-ideal surfaces, which are almost all of them in my city.  It brings out the joy of riding something fast, which must have been etched into our DNA long ago.

With speed and power comes danger!  Go too fast through a turn or cross a drop-off at an angle, and you gain a new appreciation for the tippiness of high center-of-gravity tricycles.  Someone more adventurous than me has maybe perfected the technique of balancing on two wheels to corner fast without the need for body English.  Hopefully they were wearing elbow pads.

Credit: Martin Pettitt originally posted to Flickr as Race Of Champions (CC BY 2.0)

But even straight-line speed is fun and helps eat the miles if you're going somewhere.  My first impression of the Firefly was that it's pretty darn slow.  Releasing the wheelchair's rear brake locks helped (duh), as did reading the instructions to understand that the device starts in 1st "gear", which has a low speed limit.  Setting the "gear" to 5 raises the top speed to 20 km/h (12 mph), already pretty fast if you're travelling on a sidewalk.  That's still an artificial restriction, which can be removed by adjusting the LCD controller.  Then the limit comes from the motor and battery voltage, and a fully charged battery reaches 24 km/h (14 mph).

There is a saying about all-wheel-drive cars, that they just get you to your accident faster.  Be that as it may, it would be nice to go faster than 24 km/h on smooth and clear pavement.  One option is the Phaserunner motor controller whose manual describes "Field Weakening for Speed Boost".  Apparently, the motor coils can be energized in a tricky way to gain 15-20 % in speed, at the expense of battery drain and maybe motor stress.

The Firefly's motor controller is a circuit board inside the battery base that is connected to the wiring harness.  All of those connections will make it hard to replace.  In the end, it might be more effective to replace everything (motorized wheel, the battery and maybe controller) with higher voltage parts that can go faster.  Update:  internet comments claim that most 36 V motors can operate with 48 V batteries.  I'm curious if anyone has done this already.  This could be a good project for the winter when I'm snowed in.  The cat's meow would be to also drive the rear wheels.

Parking brake

My Firefly came with a button on the right brake lever that you could press to hold the brake for parking.  This feature is great, because you can stand the Firefly up in a corner when not in use, or set the brake at a traffic light and use both hands for your phone, to dig in your bag, etc.  This is also a safety feature, because once the parking brake is engaged, accidental throttle activation has no effect.  But after about 500 km (300 miles), the button broke, and all of the parts scattered around!

What's left of the original brake-hold button.  The spring is missing and the bottom head broke off.

So I contacted the manufacturer (Rio Mobility), and they wrote that others were having the same problem, and their "solution" was to remove the brake-hold feature!  No warranty fix is possible.  I can sympathize, since the company probably doesn't want to be in the brake-lever engineering business.

But I have an affinity for mechanics, and giving up on this little bit of sweetness was not so satisfying.  Clearly, the button breaks because every time you release it, a spring causes it to pop up and smack into the brake housing with large peak forces.  The poor button can't withstand the repeated violence, and the part fails.  This seems like a design flaw, but most users of these brake levers are on bicycles or recumbents, and they won't use the brake-hold enough to cause failure during the warranty period.

After some experimenting, I ordered a replacement brake lever (Sun BL46K) for $13 that includes a brake-hold button.  This has a slightly higher quality feel than the original, but the brake-hold mechanism appears to have the same not-so-good design.

Fortunately there is a simple fix!  You can take a small cushioning washer like McMaster 93650A100 and stretch it over the bottom of the brake-hold part like a rubber band.  Now the brake lever can last a long time, because the peak forces that caused the part to fail are much lower.  Feature restored!

The red oval shows where the cushioning washer (which is transparent) was stretched over the bottom of the brake hold button.

Update (October, 2021):  Over 6000 km later, the brake-with-rubber-washer works as well as ever.  This page will be updated if a problem develops.