avoiding 20mph "wall"

9 posts / 0 new
Last post
cyclepete
Offline
Last seen: 12 years 2 months ago
Joined: Tuesday, May 27, 2008 - 10:26
Points: 64
avoiding 20mph "wall"

I've always disliked the way the Bionx handles the 20 mph speed limit. As many have noted, it feels like you hit a wall. Apparently, the assist drops from full assist to no assist right at 20 mph.

For the past few days I've been riding around with the limit turned off for the first time and really enjoyed the feel. On the plus side, my average speed is way up as I spend much more time around 20 mph. Without a tailwind but on a smooth, straight road, I can maintain about 22 mph. With even a slight tail wind, I approach 24 mph, which is as fast as I can spin with my current highest gear of 48/11.

The negative side is a significant reduction in my mileage even if I don't try to go over 20 mph. I'm estimating that my mileage per charge is down 1/3rd.

What would be nice is an "econo mode" that eliminates the "wall" effect but without hurting mileage. This could be easily implemented as a ramp-down in assist between, say, 15 mph and 20 mph. Probably non-linear so that the percent reduction increases as you approach 20 mph. Something like:
15 mph - 100% ( of regular assist at selected level)
16 mph - 85%
17 mph - 65%
18 mph - 40%
19 mph - 10%
20 mph - 0 %

Obviously, such an assist ramp-down would probably reduce one's average speed, but it would also probably increase range while still giving strong assist at lower speeds and would avoid the wall effect.

Anybody know how to hack the Bionx's control code?

spinningmagnets
Offline
Last seen: 1 year 3 months ago
Joined: Wednesday, December 12, 2007 - 20:48
Points: 295
Re: avoiding 20mph "wall"

Try here, its a BionX hack thread:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=896

Even if you don't find the solution you want there, when you do find it, it would be nice if you posted it on that thread, and also here on VisforV.

They are both well-regarded and often consulted by many...

dumb_doggy
Offline
Last seen: 15 years 4 months ago
Joined: Wednesday, July 23, 2008 - 08:55
Points: 5
Re: avoiding 20mph "wall"

Where did you manage to find an 11 tooth freewheel for your Bionx?

cyclepete
Offline
Last seen: 12 years 2 months ago
Joined: Tuesday, May 27, 2008 - 10:26
Points: 64
Re: avoiding 20mph "wall"

Looked around and found it at one of my local bike shops. They actually had two shamano freewheels with 11-tooth rings. The other one was a megarange which I thought would be too wide a range for my dérailleur. So I bought the 11/28. They charged too much for it ($30, I think).

It's gonna wear out soon and I don't have a replacement. I should of blown the bucks and gotten both.

Does nobody plan to make an 11-28 freewheel? Bionx needs to try to encourage someone to do this.

My only option at this point is to try to put a bigger chainring on my bike.

maxrevs
Offline
Last seen: 14 years 11 months ago
Joined: Thursday, April 23, 2009 - 20:13
Points: 17
Re: avoiding 20mph "wall"

Well then CyclePete, be careful what you wish for, I have just taken delivery of my new 2009 PL350, and it behaves very much like your econo mode:

16 mph - 85%
17 mph - 65%
18 mph - 40%
19 mph - 10%
20 mph - 0 %

And it SUCKS, moreover, the 3773 code no longer works. For me, my average riding speed is around 28 - 33km/s (18 - 23 mph) smack in the in the middle of "your" econo zone. Net result is the Bionx aint doing much for me, or worst, it a dead weight and drag(bionx don't free wheel) for 75% of my commute. Bionx, at first were very comunititve, but all corrispondecce has now dried up. Time to take it back and hope to get a refund.

Please, bring the wall back?

Max

MiniVan
Offline
Last seen: 14 years 7 months ago
Joined: Tuesday, April 28, 2009 - 16:48
Points: 23
Re: avoiding 20mph "wall"

I would really prefer a boost to 30KpH no matter how much effort i do or not put in... I just want a quicker commute but not faster than legally possible... I think I might save my money and go for another system. I'm like you in that I can hold 28-32 on the flat without spending $1600....

maxrevs
Offline
Last seen: 14 years 11 months ago
Joined: Thursday, April 23, 2009 - 20:13
Points: 17
Re: avoiding 20mph "wall"

This is my conclusion too, but luckily for you, you have not actually taken delivery. My aim was was to push my commute speed from around 28 - 33km/s (ish) to the to the mid to late thirties with some assist, and to have a range of up to 35 km/s. The Bionx should have given me this, unfortunately, and unbeknown to me bionx changed the specs with out informing anyone. Way to go Bionx!!!!

So, now I'm researching, (or researching again), eZee and BMC come to mind....but, please, since I think we're looking for the same beast, let me know what you find. Of course, i have get my refound out of the dealer and Bionx yet....wish me luck.

By the way, where are you, Canada?

Good Nite....Max

MiniVan
Offline
Last seen: 14 years 7 months ago
Joined: Tuesday, April 28, 2009 - 16:48
Points: 23
Re: avoiding 20mph "wall"

Hello, Have read your other posts. I too found BionX very responsive when I emailed them... I'm very interested in what the issues are with the system.

I'm seriously considering the Stokemonkey from http://cleverchimp.com/ . Unfortunately (due to cost, i like the idea) it requires the xtracycle. The concept of an 'assistance' to my peddling seems more akin to what I am after. Since it works through gears it would work at any speed... Getting use to the throttle might take some getting use to, since the throttle is how much assist to your peddling you want and not how fast you want to go. Stop peddling and you let go the throttle. The issue for me is that my frame for the bike doesn't fit the 13.5" of demensions requires to fit the monkey in the rear trianlge... I would need a new donar bike...

Anyway, I think the human computer (aka me) could adjust quite quickly to this and get my needs met... I can also do the shopping on the way home from work easier ;-)

PS: I am in Vancouver, BC

cyclepete
Offline
Last seen: 12 years 2 months ago
Joined: Tuesday, May 27, 2008 - 10:26
Points: 64
Re: avoiding 20mph "wall"

While I would like this, I had hoped they would do it as a mode that you could select, not enforce it at all levels of assist. From what I've read, the throttle still bypasses this.

In my case, I would be fine with this. Even at full throttle and pedaling in my largest gear, I seldom exceed 22 mph on flat roads without tailwinds. I find that I can cruise on flats right around 20 mph even without assist once I've been assisted up to speed. So I think this would give me a significant increase in range, reduce the "wall" effect and not be otherwise noticible to me.

But, of course, I haven't tried this yet.

Log in or register to post comments

Buy Ecotric bikes, get free accessories!


Who's online

There are currently 0 users online.

Who's new

  • Skyhawk 57
  • wild4
  • justinsmith07
  • Juli76
  • xovacharging

Support V is for Voltage