GoldenMotor.com Forum
General Category => Magic Pie & Smart Pie Discussions => Topic started by: Bassman_steve on May 26, 2016, 06:19:52 PM
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Just thought I'd ask, since most of the info on the forum seems related to throttle control...
The goal is to convert my 2008 Kona Hoss hardtail mountain bike into a road-legal urban pedelec. It's a big, beefy bike, perfectly suited to my build (6' 3", 235lb).
The Hoss may represent some mounting problems, because of the way it's configured:
- Downhill MTB hardware, including oversized handlebars, seat post, stem, etc.
- SRAM hydraulic disk brakes.
- 7-speed cassette.
- Marzocchi suspension fork.
I spend a lot of time riding on the paved bike paths here in London, Ontario. As a result, I need a quiet unobtrusive drive system. I would prefer it to be controlled by my pedalling effort, rather than a twist or thumb throttle.
Motor-wise, the Edge looks like a perfect fit for my requirements, so now it's just a matter of choosing the right accessories.
What controller and sensors should I use to get a smooth, intuitive pedal assist? I rode an early 36v Bionx conversion a number of years ago, and would like to emulate that smooth, effortless "magic legs" feeling.
Will I need special hardware to mount the display unit on the fatter-than-normal bars?
How do I go about triggering a motor cutoff from the SRAM brake levers (integrated brake fluid reservoir)?
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What controller and sensors should I use to get a smooth, intuitive pedal assist? I rode an early 36v Bionx conversion a number of years ago, and would like to emulate that smooth, effortless "magic legs" feeling.
I think the pedal torque sensor and Cycle Analyst will be needed to achieve the smooth pedal assist that you are looking for, but they are not cheap:
(http://www.goldenmotor.ca/product_images/k/192/CA3_TorqueKit__10082_zoom.jpg)
Click for more details. (http://www.goldenmotor.ca/products/Cycle-Analyst-Version-3-with-131mm-THUN-Sensor-Package.html)
Will I need special hardware to mount the display unit on the fatter-than-normal bars?
I don't know what diameter bars the Cycle Analyst mounting bracket will accommodate, you would need to ask Gary (GM Canada (http://goldenmotor.com/SMF/index.php?action=profile;u=8525)) for more information.
How do I go about triggering a motor cutoff from the SRAM brake levers (integrated brake fluid reservoir)?
Regarding the brake switches, it might be possible to adapt your existing brake levers (https://endless-sphere.com/forums/viewtopic.php?f=3&t=52079) by fitting a microswitch or magnetic reed switch etc. to sense the lever movement, but if you cannot easily adapt your existing brake levers, Gary also sells complete hydraulic brake kits:
(http://www.goldenmotor.ca/product_images/r/081/h_brake_2__56287_zoom.jpg)
Click for more details. (http://www.goldenmotor.ca/categories/Parts-and-Accessories/Brake/Hydraulic/)
The above levers have an integrated brake switch to cut the power to the motor and engage the regenerative barking when the levers are pulled.
Alan
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Hi Steve
in the beginning (2012) I started with the same intention: PAS only control. The MagicPie 3 (that was the top model at that time frame) was very sturdy at the EU 25km/h + PAS limitations. After my first MP III Problems (defective controller) was solved I used the frequency of my 12 pol PAS to generate a throttle signal (quite simple with a Frequency-to-Voltage converter). As It starts it's signal from the first movement it's much more easy to control the bike, BUT as soon as I need to be very slow (train crossing, moving around obstacles, ... ) it helps to have a throttle in reach to get in control again.
Alan's suggestion Cycle Analyst is quite the best way, as it tooks a lot of sensor information and not only the PAS which is very crude with the typ. 6 pols. It might be a lot of money at frst, but pays out in the coming years. As I could not use a torques sensor (no chain/gear) it was out of question, but for you it might be just the right toolset.
In the meantime I switched to a optical sensor which reads a black/white board (which rotates) and delivers 120 impulses per turn, which is smooth par excellence with my F/V converter (just 5 pieces of hardware).
As I'm using Magura hydraulic brakes I bought an (inofficial) brake switch from a workshop at magura four years ago which works flawlessly front + rear since then.
Cheers
Sam