A hybrid bike

My hybrid bike: the X-treme XB-310Li 

I have been looking at other types of battery-powered transportation ever since we bought our Highlander4WD hybrid about 5 years ago.  Initially I looked at motorbikes and scooters while they transitioned from lead acid to Li-ion batteries.  At the upper end, such bikes can go for as much as 10K, often US- or Japanese- made, and at the other end the Chinese manufacturers have the market.  I had specifically been looking at motorbikes from a manufacturing group called X-treme, but after a recent visit to Holland I decided that powered bicycles ("e-bike") deserved another look. Much like their fully motorized counterparts, e-bikes come in many flavors, and, as many early-adopter toys, can be finicky.  However, given the potential for engine-related fails, an e-bike has the advantage that one can pedal on without engine help, while motorbikes leave you stranded.  So, I made the plunge after a little more internet research (incl Amazon.com) with an X-treme bike that has a 24V Li-ion battery offering pedal-assist (so, tailwind or downhill both ways) or can be propelled with a mere handtwist. Reading the user comments and experiences on several forums, battery-powered bicycles and motorbikes can be as much a hobby as a transportation means, but, when working, they do deliver as promised.  The aluminum, 7-gear X-treme I selected seemed to have similar performance to others, but is more moderately priced (I paid $699, incl shipping at FarBike).

My ~52lbs X-treme bike shipped by UPS and arrived in parts (shown below) and after, mostly instructionless, installation, proved complete.  No parts were missing (I think), nor left over!  The enclosed manual is sparse and demands user interpretation, with several key items never even mentioned, yet critical to the final construction (like somehow inserting the rear suspension module). For added convenience I bought the folding model, which works fine and the construction seems sturdy (with lock clip).  The controller and battery are in a lockbox (Al Gore style) under the saddle, limiting the ability to lower the saddle to a person more than ~5'10" in height (or with long legs).  This configuration also requires a race-like forward riding mode that is less comfortable than I want (see my modification below).

After bike assembly, the battery and charger both worked, and after 3 hours the laptop-like charger indicated that the bike's battery was juiced (a green light showed).  The indicator on the battery itself suggested it was full on delivery, or simply indicates that it works.  Other than inserting the battery pack in its slot and turning a key, the power train requires no installation.  A quick test ride and I learned that power is delivered immediate and without gradation.  Pedal-assist means that after one turn suddenly something seems to be pushing you, just like a permanent tailwind.  Alternatively, the handtwist offers power without any pedaling and is likewise all or nothing (only delayed by inertia).

After my first trip to work and back, it was clear that several cheap parts (below) were used, as was mentioned in online forums too.  Several bolts needed tightening too.

  

So, I bought new handle bars that offer palm support, a new saddle that has strategic padding (and bolts that tighten) and an adjustable handlebar stem.  The latter allows me to raise the handlebar, so that a more upright posture creates less strain on the hands and wrists.  The new grips were slightly longer than stock (and different length for left and right to fit the handtwist), but easily fitted by moving breaks and such with the include (cheap) toolset.  I spent about $60 on these items and now the bike is a lot more comfortable.  My final configuration is below.

I bike about 5mi each way to/from work and notice no loss of battery power.  The manufacturer advises against draining the battery, so I fully recharge it when I get home.  Meanwhile, the tailwind sensation is addictive and makes the distance seem half.  Uphill is also much easier and on level parts one can just cruise using the handtwist.   Perhaps less of a workout than before, but also less excuse to take the car.  Once they become more available and visible, I believe that e-bikes have a clear future and could put many more people on bikes, greatly reducing the carbon footprint and offering much-needed exercise.  The energy required to charge the battery is similar to a lighting bulb (~60W), so inexpensive to charge.  We'll see about reliability in the next few weeks to months, which I will include as a follow-on update. 

UPDATE, 4 September 2013.

I made two additional modifications to my bike.  I wanted a more upright posture than originally possible, so added a new, lightweight 5" handlebar (picture).  Make sure to order 31.8mm diameter at stem, which is thicker than standard ends.

With the new handlebar+adjustable stem, there is optimal flexibility with height and lean-in for taller folks.  Also, the controller rattles in its plastic case, which cannot be good for the electronics and is annoying on bumpy roads (= all roads in my town).  So, I added some padding to the inside of the case, using heavy-duty frame insulation tape, which fixed this issue.

I have been using the bike ~3x per week, 10mi each; I recharge every night (with a timer).  So far, I have had no problems, and the bike is performing as new.  Remember that this is a bicycle with paddle-assist, which makes the ride lighter.  It is not a motorbike, and throttle operation only works well on flat and downward surfaces; it is poor on any upward slope.  In my hilly (and bumpy) town, paddle-assist makes the difference.  The occasional sideways glance from other bikers is amusing, especially when I comfortably coast past them. 

UPDATE (Fall 2014).  Rattling battery pack fixed by inserting a foam base in box and tightening some screws.  The rear tire developed warp as a result of (unidentified) broken spokes, noticeably affecting ride.  Installing two new spokes from local bike shop (custom length, $1 each) took only moderate effort. I discovered this problem late, so hard to get rim warp out.  Otherwise, bike is working as before and just readied for Spring use.

UPDATE (Spring/Summer 2015).  DISASTER!  More spokes snapped and it turns out that spoke holes are too large for standard gauge replacements.  Need to respoke with washers at considerable repair shop and parts cost.  (After repair) Respoked rear wheel working just fine.  Earlier vibration from uneven spoke tension is gone and, of course, warp from formerly broken spokes is gone too.  Some bolts have loosened and the battery box is back to rattling.  The foam probably did not survive a cold winter in storage.  All easy fixes.  Charging/discharging unchanged from last year, with no loss of power.