Bionx vs others in "feel" of the riding

Hi
I have been researching electric bikes for a few months. Finally I got a chance to ride several different types: Hebb, E-moto, Pedago, and a Bionx system.

First let me give you my back story. I am a 110 pound 48 year old woman living hear Lake Tahoe. I love to bike, on bike paths and on trails with my mountain bike, but I am awful on hills. I want an electric bike to help me get up hills without having to walk and slow everyone down. I don't care how fast I go, and in fact don't like to go too fast. I probably would never ride over 20 miles. But the most important thing is that I want to feel like I'm riding a bike. Those first 3 bikes, even while in lowest assist mode, felt like glorified motorcycles. I couldn't even find a way to get a workout without the bike forcing me to go way too fast. (The Pedago was the worst; it takes off when you are standing next to the bike if the pedal happens to turn.) Finally I rode a Bionx and it was completely different and just what I was looking for! I was actually riding the bike myself (what a concept!), and it just helped me get up hills. I understand that Bionx detects the torque you are exerting on the pedals and uses that to know when and how much to kick in.

So the question is, what is that technology called that works like the Bionx, and are there other bikes that use it? Most of the bikes say they use torque sensors, but it is clearly different. Or is it not the technology but just the quality of the controller design? (My husband and I are engineers so you can answer technically.)

Second thing I cannot figure out is what motor size I should get. Most shops tell me that since I am lightweight, a low watt system is fine for me. But I do need hill climbing ability and decent range so I don't run out in the middle of a ride. With a Bionx do you think 250W is fine or should I get 350W to make sure? (In other brands it seems to be more of a choice between 350W and 500W.) I have to drive to California to test bikes so during short test drives I can't run the kinds of tests I would like to be able to run in order to test this out.

My understanding is that I don't need a high V system like 48v because I don't care about going fast. Is that correct? Or does voltage help on hills also?

Thanks! I really appreciate any input pointing me in a direction.
Cindi

Cindi,

I agree with you that Bionx has the best assist feel of the commercial bikes and store-built bikes I tried. Some of the pedal sense bikes are nothing more than on/off switches switched on by pedal rotation. Others have torque sensors, but none seem to work as well as the Bionx, and probably due to the Bionx torque sensor in the ideal location, on the rear axle sensing the tension on the sprocket being driven by the chain which automatically compensates for the selected gear, and also to obviously very well executed software. I put about 13K miles in three years on my first 36V 350PL before upgrading to the new 48V 350HT. They are both the same top speed, but the 48V system is lighter and stronger and smoother. By stronger, I am mostly referring to how well the battery holds up, leaving me over 1/3 charge after my 22 mile round trip commute to work, where the 36V system generally had 1/8 charge if I didn't face too much headwind. While the 36V system is awesome, perfectly quiet, and barely noticeable about power application and adjustments, the 48V is even more polished in every respect.

My route has only small hills on the bike path overpasses and underpasses, where there is not much slowdown (20 MPH down to maybe 17 MPH, when half the other riders get off an walk up the ramps). Interestingly, when I am doing 20 MPH, it is 100% my own legs, as the Bionx assist tapers off from about 12 MPH to zero assist around 19 MPH. Changing the assist levels does more to change the amount of assist getting up to speed, but barely changes the top assist speed at all. When I ride at level 2 (nearly all the time), I will down shift two or three gears at stops, but at level 4 there no reason to ever take the bike out of the highest gear. Level 1 on the 36V system is barely noticeable assist at all. Level 1 on the 48V is what I would describe as level 1.5 on the 36V.

I think you would be happier with the 350W system because of the hills. I would probably do fine with a 250W on my nearly all flat ride. However, the 250W systems may not have enough range for me. Also, Bionx rates their system at nominal power, not sustainable peak power, like some motor manufacturers do. I get as much assist on my 350W Bionx as I have felt on other 750W systems. I would compare the Bionx "350W" to most other 500-750W systems. The battery capacity, both amp-hours duration and C rating power delivery potential is more important than rated motor wattage.

Would you like to buy a used 350 PL that still has about 80% of its battery capacity left?

-- Alan

I agree with alan. Friend has a 36v 350 w Bionx and thinks it is the best thing since Trader Joes wine section.

you will love it after you get over the price.


what it will not do is carry really big guys (200lb +) up long 2 mile steep hills in the heat 95F +of summer.

You must buy bionx parts and service, which can be expensive. However the ENTIRE system now has a 2 year warranty including battery.

Be sure to put it on a bike you really like, a pretty new one that is just broke in and fits you well. you can get 40 mile range at decent assist level after you learn the bike. Get a good saddle cause you will be on the bike a lot.

d in colorado

Hi Cindi,

I agree the Bionx is a nice system. You probably also want to take a look at the Dolphin E-bikes. The "slow" models still feature a 500W motor that will get you up a hill as described.

I would suggest not to go for a "lower" power motor, regardless your weight. If you want to go up a really steep hill (like 20%), a 250W motor is not going to cut it. And with a higher power motor, you can always select a "lower assist" setting if the help is too much for you to get your workout.

Even better to find someone who can build it for you. Just select your favourite mountainbike, put in a nice 500W motor, small 25A controller (allowing for peak performance of 900W at 36V), Thun torque sensor, cycle analyst version 3, nice lightweight battery, and off you go.

For your purposes, I honestly do not believe that there is a lot of difference between 36V or 48V, apart from topspeed as you already mentioned. Most commercial e-bikes are limited to 250 / 350 / or 500W anyway. What then changes is the amount of current that flows through your system. For a 500W system, using 36V would mean a current of 13.8A, whereas a 48V system would mean a current of only 10.4A. As mentioned, you will not notice that when going uphill if your controller is limiting the motor at 500W anyway. It will matter if you start tinkering with the controller to increase the power.....

To get a better idea, if you want to go uphill with 50kmh without pedalling, you need to come with at least 3000W. At 74V, that means a current of >40A.

Hi Miss Cindi!

We have two(2) Bionx systems. One on each of our Catrikes. Although I have other bicycle projects that are fast an furriest, the Bionx
is amazingly suited to those who just want to pedal and have assist.

Even though the Bionx system has four (4) levels, the brain can be programmed to give you the best feel for your age,weight and athletic ability.
A good Bionx Dealer would know how to change the programmable settings

Tommy L sends....... \\m//

Programmable? That's cool!
Thanks everyone.
Any thoughts about the rear mount batteries vs the bottle mount? I know bottle mount is supposed to be a little more stable, but not sure in practice if there is much difference. It seems stealthier to put on the back. (Can you put other stuff on top of it too or would it overheat?)

Cindi

Hello new friend:

Lake Tahoe is a beautiful place. I've been there many times in both summer and winter. Love Lake Tahoe.


I would recommend getting something like a Trek Plus. They use the Bionx system and have a good warranty to back it up on both the bike and the system. If you have any problems you just bring it in to the shop and they take care of everything. I don't know if there's a solid Trek dealership near you. There's a Trek store where I live (that only sells Trek and other Trek-owned products) and their service is incredible. I can ride in anytime (or drop off my bike) and they tune it up free (lifetime on gears and brakes, plus they clean and lube it each time). If you have such a store within 50 miles or so it would be worth the extra cost (in my opinion).

I'm trying to convince my dad to get one, and since it does all the thinking for you it's a great ride. Plus, no maintenance (let the shop do it all).

If you choose to have someone install the system on a bike you already own, just make sure they know what they are doing and can back up all their work.

Finally, the battery on the 350 watt system (don't get 250 watt) is not heavy at all, and the rear racks that come with the Bionx system (if you order the right rack) have the battery in between two layers of racks, so you can place gear on the rack.

Here's a link to their site: http://www.trekbikes.com/us/en/collections/electric_assist

This one is $2100 bucks and looks sweet.

Finally, see if there is any kind of tax credit in California. Who knows. Maybe you'll get it partially paid for by the state or feds.

Have fun and good luck (wear a helmet).

Most bikes/systems that claim to have a torque sensor actually just use a cadence sensor that just counts revolutions at the bottom bracket. Other than Bionx there are a few european and asian brands that use panasonic/bosch systems with torque sensors (as I understand it) or if you're looking for something more DIY the new CycleAnalyst 3 (still in beta) from ebikes.ca and a thun torque sensing bottom bracket cartridge from the same will let you build it into the system of your choice.

Best of luck,
SK

i am planning to alter my current 500W setup to run the thun Tq sensing BB and CA V3 once the software gets out of beta.

i test rode a trike that had a PL350 bionx system fitted, and i loved it.
from that day, i decided that i will be running the thun sensor with CA V3 to emulate the bionx setup.

that way i can have a true assist based upon how hard im pedaling, but i am NOT locked into
expensive proprietary controllers and batteries etc.

Jason.

How a bike feels is very much up to the individual. Different bikes have different control systems and different algorithms in the controller software. To me, it's not a question of whether it's a torque sensor or cadence sensor, it's what they do with the signal from it.

Before you make your final decision, you should try a bike with the Bosch crank-drive system, which is also very simple and natural to use, and more choices of bike style/shape and size. Another of my favourites and a lot cheaper is the BH Emotion Neo seies that are strong climbers, but can also be ridden gently with their relatively light weight and variable assist levels.

This thread here goes over a number of features and differences between the 350 vs 500
http://www.bikeforums.net/showthread.php/823804-Bionx-350-vs-Bionx-500

In regards to the rear rack vs downtube mount here are the pros/cons I found:
Rear rack:
Pros:
-USB power plug
Cons:
- Balance not great due to the weight at the back of the bike
- Can not install a Topeak rack which allows quick release trunks (I find it very helpful vs the bulky paniers)
- Can not carry a Wahoo trailer

In general I would never leave the battery on the bike when parked outside - either downtube or rear rack mounted. It very easy for a thief to force the locking system with a screwdriver.