500w BionX OFF ROAD

[2old]

Rode a 2015 BionX installed in a hardtail MTB the other day and was amazed at the power. It ascended a steep (for me) hill from a full stop to 20 mph in about 300 feet (rough estimate). No other CA legal bike that I've ridden comes close including bikes like the Haibike XDURO and Focus Full Suspension (FS) mid-drive. The thing that I have no experience with is how this system would handle rough off road descents with its heavy rear wheel. Anyone have any experience with BionX on a hardtail or FS bike off road?

 

[2old]

Nobody?

 

[greg_p]

Not surprising.
My wife has a bosch 250W assit bike, and running with her and my bike (that has a CA v2 power meter), I can tell the bosch motor push more than 500W uphill on turbo mode. So it's not surprising at all that a "commercial" assit system push more than advertized.

 

[dogman dan]

In general, the hard tail and a heavy wheel is very rough on rims, spokes, and pinch flatting tires. But that depends a lot on the type of trail you are riding. If' it's really bad, like a rock staircase, then you'll have some issues. Same for large jumps.

But if it's kind of nice trail, no real problems should be expected. For me personally, It's gotta be full suspension for off road riding. It's rough here in New Mexico.

 

[2old]

Thanks for your responses. I love the Haibike, including its off road capability but it doesn't compare to the BipnX. Guess I'll eschew the rear hub though since some trails are pretty eroded in CA too.

 

[greg_p]

If you can test and check the rear wheel weight but the website advertises 8.8kg for the system which is good, but I think we can do better figures for rear wheel setup...
Bionx has 48V / 11.6 Ah and 500w rear wheel , 8.8kg and 2500$ the conversion kit.
For roughly 2000$ you can have a eZee kit at ebikes.ca + the battery. The battery, you can source it in other place, such as em3ev triangle battery that will fit into your bike, and this one for example:
http://em3ev.com/store/index.php?route=product/product&path=35_51&product_id=123
will completely outperform the bionx:
Ebikes setup/em3ev battery: 1125W max pow, batt 950wh, 115Nm max, 158km@ 35% assist. 2000$
Bionx Setup : 500w max pow, batt 555wh, 9.0/25.0 Nm, 105km max @ 35% assist, 2500$
you'll be less restricted with ebikes, you will choose to respect or not any speed limit, pedal assist or not at any moment.
And the support from grin/ebikes and other known seller as em3ev will surely be far superior, also with very repair-ability.
The main differences will be that integration of bionx will be superior, because you just have 1 cable from rear will to battery pack (that may enclose controller), and display will look "on the edge", and on the other side, it will ask more work to integrate all cables and hide them and you may look like a nerd. The CA will have to be set-up, also with software from grin. You may ask them to configure it...

 

[Teh Stork]

If you can test and check the rear wheel weight but the website advertises 8.8kg for the system which is good, but I think we can do better figures for rear wheel setup...

Ebikes setup/em3ev battery: 1125W max pow, batt 950wh, 115Nm max, 158km@ 35% assist. 2000$
Bionx Setup : 500w max pow, batt 555wh, 9.0/25.0 Nm, 105km max @ 35% assist, 2500$

I cringe at coming out in Bionx's defence, but that comparison is wrong. The 500W Bionx run somewhere around 1kW max and definitely has torque in the 50-70 Nm range. The same goes for their 250W system that peaks at around 1000 W.

In the end, it boils down to watts delivered. Comparing a "1000 W" Direct drive system to a XDURO "Designed for 250W but operated at bloody max"-crank motor will come out in favor of the first.

If you have the opportunity to try a Bafang BBS motor around 500W - 750W, it will outperform the Bionx system - no problem. Off road it performs much better than a direct-drive motor, but it comes at the price of maintenance and cost.

The main problem with off-road riding and ebikes is that unfit users do not use their legs to absorb bumbs and jumps - instead sitting down on the saddle. Combine this with motorized power and a tough trail - and any motor config can kill the rear wheel.

 

[Cephalotus]

Rode a 2015 BionX installed in a hardtail MTB the other day and was amazed at the power. It ascended a steep (for me) hill from a full stop to 20 mph in about 300 feet (rough estimate). No other CA legal bike that I've ridden comes close including bikes like the Haibike XDURO and Focus Full Suspension (FS) mid-drive. The thing that I have no experience with is how this system would handle rough off road descents with its heavy rear wheel. Anyone have any experience with BionX on a hardtail or FS bike off road?

Most bionx systems use 30A max controllers (no matter if labeled 250W, 350W or 500W), so in combination with a fully charged 48V battery (13s) you have a 48V * 30A max. system.

Which 500W BionX motor did you use? The old "standard sized" HT / P Motor or the disc shaped thin d-series motor?

The first one rides very fast in the flat (removing the speed limit is supports up to 70km/h in 48V systems using 28" wheels), but at the expense of torque (afair 25Nm max, 7Nm continuous) and will go into heat protection quickly. The d-motor can get hot, too, but takes a lot longer and offers 50Nm of maximum and 25Nm continuous torque. The d-motor offers longer spokes, it is said that this benefits the offroad experience (no experience here)

The old motor weights 4.7kg, the new d-series motor 3.9kg.

If really ride on "roads" where you need(!) a good full suspension bike don't add 4kg+ to your rear wheel but use a mid drive instead. Most rear motors are better used in hardtails anyway imho, but some ES people will probably disagree... Add thick tires with low pressure and you get some "suspension" for the rear wheel, too and you will be fine on most roads where a heavy weight hardtail is good enough.