Immediately after ENVO D35 successfully launched late 2018, we received several comments from our professional dealers as well as individual users inquiring about ta Step-thru version of this ebike. An electric bike with similar frame technology and weight and same e-assist system delivering same performance, stylish look, weight and cost, but with a low entry frame. Challenge accepted!
As e-bikes and other electric vehicles offer mobility to people whose health makes regular pedal bikes difficult to ride, the Step Thru also fulfils this role. The design means if you would ordinarily have trouble mounting a regular bike, you can now hop on and off with ease and enjoy all of the health benefits from riding an e-bike.
If you like to wear baggy shorts, a skirt, or dress, the design can stop you revealing too much when you get on or off the bicycle.
While these are all practical reasons, lots of people simply prefer the more elegant design of the Step Thru over a more angular e-bike frame.
As a product design project, 75% of the product specs of ENVO ST are pre-determined as this bike by ENVO D35. Using a common platform for main electrical and mechanical components is the key factor to keep spare parts standard among various models making maintenance and aftersales service simple for partnering bike shops.
Remaining problems to solve knowing the standard features of ENVO D35 with 27.5″ wheel size, same motor, controller, battery, etc. would be as follows:
North American market expectations on desired product
Who needs the step thru ebike?
Almost all age groups, health condition and genders can be potential users of ENVO ST. Obviously ENVO ST would be less athletic/performance than D35 but more comfortable, relaxed and ad
aptive. ST should also address needs of a wider spectrum of riders among seniors, those with hip, knee or other physical injuries or disabilities as well as ladies who want to ride regardless of how they are dressed. Over 16 of age, from slightly under 5′ and up to 6’5″ 250lbs should safely use it as commuter or trail pleasure.
How will Step thru ebike be used?
ENVO ST is a comfortable urban electric bike with high trail capabilities. As an ebike, should be capable of climbing hilly roads and trails with a reliable braking system. It is not a candidate for downhill mountain biking or road racing.
What key features to be maintained or added?
Maximum street legal performance of 32km/h (20mph) and average 10% ability to climb.
Style and look which can be proudly claimed as a Canadian electric bike.
Stability and ease of control on high speed for paved and trails
Light weight for keeping balance, lifting and hanging on bike racks
Best and safest braking performance with 180mm rotor hydraulic disk brake
Enough range for a maximum daylong ride tolerance of an average healthy rider in low to average level of assist
Low temperature tolerance for battery and electronics for operating temperature as low as -20C
IP65 protection from dust and water splash from any angle for electric components.
Product market positioning and Benchmarks
North American and European or A grade Asian electric bike brands such as Trek, Specialized, Gazelle, Cube, Giant, Cannondale, etc. with reasonable specs are priced some where above c$3000 (US$2200). The other side of the spectrum there are Asian products such as Radpower, Velec, Diadora, Junction, Ancheer, etc which are offered low cost at below C$2000 (US$1500) but with compromised quality and missed features. ENVO needs product in the MSRP C$2500 (US$1900) including all desired features, without a single quality sacrifice.
Cost of ownership, maintenance and service
ENVO ST should maintain use of standard bicycle parts such that can be serviced and replaced by any intermediate bike mechanic anywhere. All electric components should be modular and easy to replace for DIY repair and replacement in case of failure. ENVO business model should make the maintenance and repair simple, cheap and available for remote areas.
Frame design and battery positioning
Simply the upper tube needs to be eliminated and battery should find a spot with minimal center of gravity height out of the way of the step. Frame should be stylish with fat but thin-walled hydroformed aluminum profiles and not much deviated from D35 frame design features.
Frame ergonomic design
Seat tube angle, effective top tube length, head tube angle, wheel base, seat tube length are the major dimensions to be maintained such that guarantees the comfort and healthy posture of the rider.
ENVO ST would mostly be considered a comfort urban bike than a performance hard tail mountain bike. So the seating position to be designed more upright with the adjustability option for people of various height. A wider comfy saddle and a quick release adjustable handle bar stem to be added as featured components.
Frame with 27.5″ wheel size should be comfortable for any rider from below 5′ to above 6′ 4″
Frame strength and reinforcement
By eliminating the upper tube, strength advantage of the closed triangular frame is missed. Now it needs the downtube profile be reinforced at certain spots including welding joints to head shell as well as seat tube to bare the bending moments due to heavy rider weight of braking loads. Any reinforcement or change in profile section should be a part of the style consistency. ST is not expected to be more expensive nor heavier than D35, that makes it even more challenging.
Project update: Frame Sample Manufacturing