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December 9, 2017 4:46:23 AM PST

There are a number of information pages that we were working on this year but only now with the relative calm of the winter season have we had the time to wrap them up. So for your fireside reading pleasure, we offer you

  1. ConnectorsGrin's Ebike Connector Guide:  A summary of the various standard connector types encountered in ebike conversions and our take on them from the DIY user perspective. For those dizzied by the wide assortment of connectors out there hopefully this page can help you make sense of some of it.
  2. Mid-drive vs Hub motorOur take on the Merits of Hub Motors: In our travels this summer to meet with other ebike businesses, one recurring theme was that most of them felt hub motors have been subject to a lot of misleading marketing in recent years by mid-drive companies. We've played with many mid-drives as well since our founding days, and while they have a few advantages in some situations our feeling has always been that hub motors are a better overall solution for the needs of 80-90% of ebike users. Even with the popular proliferation of BBSXX type drives, that viewpoint hasn't changed at all. To wee why, read here.
  3. Cooked motorHow many watts is that motor?: This is a question that makes Justin's blood boil a little. If there is one thing that is most often misunderstood about ebike technology it's the topic of motor power ratings. Did you know that the european Bosch ebikes will draw 700-800 watts of power form the battery even though they are, you know, supposedly 250 watt systems? It's true. We've always avoided giving specific power ratings on our motors because the number you choose is rather arbitrary, and this more technical article explains why. 
  4. PatentsFrom the past: We also found the draft documents from an old article we wrote in 2010 on the role of the DIY ebike scene at that point, and we thought would be nice to dust off and make available online again.
Posted By Justin Lemire-Elmore

Bits and Bobs

November 17, 2017 5:14:29 PM PST

We've got two new Grin items hot off our milling machine that should help overcome difficulties in electric conversions.

The Handle Bob

The first idea actually comes courtesy of our customer Bob. Bob you see has a Grin All-Axle bike conversion and ran into the familiar situation of having handlebars that didn't lend themselves to sliding on a throttle. This happens all the time with curved drop bars, oversized handlebar tubing and whatnot. His solution with a piece of 22mm OD tube cut and drilled to secure at right angles with a pair of cable ties was so elegant and simple that we had to make this into a product.

 Bob's Original Bar Solution

So in his honor we introduce the Handle Bob, allowing you to easily attach a small bobbin to handebars on which you can affix a thumb throttle, CA aux input, headlight button or other small device without needing to remove your grips or anything else. It's the simplest and lowest tech product that we've ever manufactured in our little machine shop, but one that just might have a big impact for many builds.

HandleBob Pair HandleBob with Digi Aux Buttons HandleBob with Lever Throttle


The Bottle Bob

BottleBob on Tube BottleBobs and HoseclampsThe 2nd item helps when installing downtube and waterbottle batteries on bike frames that don't have properly located waterbottle braze-ons. We're calling these our Bottle Bobs, and they let you add a solid M5 threaded attachment point anywhere on your bike tubing with the security of a stainless steel hoseclamp.


In fact, these attachments are stronger and more secure than many of the riv-nut frame eyelets which can occasionally tear out of the frame tubing with heavy batteries, and allow you the security of having 3 or 4 attachment points to the battery base plate rather than just the 2 when you use the frame's bottle mounts.

Hailong Battery Installed on Bike Frame with No Eyelets

And of course, you can also use them to attach more waterbottle cages to your bike!

Both the Handle Bobs and Bottle Bobs are already available from our store, manufactured at Grin from machined aluminum and black anodized for a lasting sharp look.

Posted By Justin Lemire-Elmore

Who wants a high wheeler?

November 7, 2017 2:53:19 AM PST

At the VEVA electric vehicle show this summer we showed up with two electrified penny farthing bicycles, thinking that we could stage electric high-wheeler races around the mini test track. The racing didn't happen but the fun of riding these around Vancouver hasn't abated. There haven't been too many accidents and the reaction on the streets is pretty amazing if you like making people crack a smile. Aaron and some of the new staff at Grin made a nice video from an afternoon spin:

More specific details on how these were built are shown on the endless-sphere build thread:

Anyways it turns out that there are a couple dozen more replica high wheel bikes from this source in a storage locker looking for a home, and we wonder if there is a case to sell them electrified with small hubs in the rear wheel. The bikes are available in wheel sizes ranging from 36" to 54", and they have a custom machined freewheeling front hub so you can coast without pedaling. If owning a piece of 19th century bike technology merged with 21st century electronics like this tickles your fancy, then send us an email and we'll see if there's enough interest to convert a batch! Price would depend on the specific conversion options but can expected between $1500-$2000.

Posted By Justin Lemire-Elmore

It's high time to formally introduce our Battery Grinspector, a device that converts a Version 2 Cycle Analyst into a full computer controlled battery test station. Here is a nice video that Bruno made while we had a prototype to show at the Taipei Cycle Show earlier this year:

This is our first foray into products aimed at shops and businesses that have to maintain and service electric bicycles rather than to ebike end users. As more and more ebike shops open up, there's an increasing need for ebike specific diagnostic and repair tools. We hope it finds a small but growing audience!

A little background

Over the years we've built all kinds of custom battery discharge testing rigs for the troubleshooting, QC, and R&D needs of our operation. But each has been very much a one-off project, rather than something designed with the idea that we could manufacture it as a product. The one on the left is Justin's very first battery charge/discharge machine built for conditioning and testing salvaged NiMH batteries for his first ebike project at university, while on the right was a comprehensive labview controlled solution that would cycle test 8 packs at a time.

Early battery tester for cycle testing and conditioning salvaged NiMH packs Example of test plots showing cell reversals An early ~2006 battery tester we made for a local ebike shop Voltage EV A later revision that with an active programmable load for automatic cycle testing at different currents This 8 at a time labview DAQ controlled tester we made in 2007 and it served us nearly 10 years, performing 10's of thousands of battery discharges in the process  Closeup of our 8-pack custom made test station, retired at last earlier this year

Commercial equipment available on the market for testing batteries tends to be bulky and expensive, made for laboratory or industrial use and wholly out of place in a bike shop. As a result, we noticed many of our dealers have setup simple improvised rigs using a Cycle Analyst and load resistor to do a simple battery capacity test.

Battery Grinspector Basic Layout

The Grinspector station builds on this concept, allowing allowing shops to use their familiar Cycle Analyst while a computer is able to control the charging and discharging of the battery, with real time discharge graphs as well as a final printable QC report. Everytime someone purchases a battery from us, they get a printout of the battery discharge curve showing actual capacity and other test data. That's our own bank of Grinspectors at work, and we hope to empower other shops to do the same.

Posted By Justin Lemire-Elmore

Fall Web Enhancements

October 5, 2017 10:24:31 AM PDT

add custom spokes to cart

Over the last few months we've quietly slipped a number of other small improvements to our website. For instance, from the spoke calculator page you can now directly add spokes to your cart from the calculator, no need to write down lengths and navigate back to the online store.


Launch simulator from kits page

Similarly, when you are shopping for the conversion kits, the simulator link on the bottom will launch the motor simulator page with the correct motor, controller, wheel size etc. already pre-selected.

And if you have individual motors, controllers, batteries etc. in your shopping cart, then you can launch a local instance of the simulator tool from inside the cart to see exactly the performance of these items and how they work together.

Inline Shopping Cart Simulation

Additional Simulator Updates

The simulator improvements have only kept continuing since the September update. There's now the ability to model custom motors, to set a controller for a torque or amps throttle, and to have the throttle automatically adjust itself based on where you click the graph. Read the updated FAQ section and have fun.

Much of this work and the associated tools for motor thermal analysis was possible with the help of our summer software coop students from SFU and UBC; Stefan, Gary, and Adam. It's long overdue we gave them a big public thanks for their fine contributions.

Gary, Stefan, and Adam


Posted By Justin Lemire-Elmore

Motor Simulator, 2017 Updates

September 2, 2017 9:12:00 AM PDT

Hope that everyone is having a great labour day long weekend. This past month we've wrapped up signficicant batch of upgrades and new features to our online hub motor simulator. This list includes

List of new 2017 features on motor simulator



Posted By Justin Lemire-Elmore

Thinner Throttles and Beefier Ebrakes

August 4, 2017 11:30:00 PM PDT

One of the common sources of fitting issues with conversion kits is interference between the throttle and existing lever shifters on the bike. We have two new throttle options that help things on this front. The T-Lever throttle fits equally well on both the left and right side of the handlebar for maximum install flexibility and is ~2mm smaller in diameter than our previous thumb throttles. And the T-HTwist_Slim throttle is a split grip throttle with an impressive 36 mm max diameter (vs 45-50mm with other common models), allowing it to replace almost any right side grip without concern for shift lever interference. It has a standard handlebar grip diameter right to the end. 

Comparison picture of new throttle options


Beefier Ebrake Lever OptionWe've similarly upgraded our basic mechanical ebrake option to a sturdier model with a longer black lever arm and rubber grip in the front. Both this and our previous silver model are all metal construction, but the new black one is better suited to the quality standards that we'd like associated with our offerings. Our remaining stock of the previous model of ebrakes and throttles are available for sale on our new sale/clearance page.

Posted By Justin Lemire-Elmore

Controllers and Motors with Waterproof Z910 plugs

August 1, 2017 12:07:42 AM PDT

We've spent 10 years of determined effort keeping all of our kits, controllers, and motors interchangeable and standardized around the same 3-pin Anderson and 5-pin JST hall connectors, but we're moving on! At this point, most manfufacturers of small ebike motors have adopted the overmolded 9-pin Higo Z910A plug as a default connector type, and rather than always cutting this off and replacing with andersons we've decided to roll with it and make our smaller 20A Grinfineon Controllers directly compatible.

Higo Z910 Plug

The extra 6th signal wire is used in geared motor setups for an internal wheel speed sensor that is present in many geared hubs, allowing you to get vehicle speed info from a simple CA-DP device rather than needing a separate speedometer sensor and spoke magnet with the CA-DPS. In our small direct drive motors, we've used this 6th wire for the internal motor temperature sensor that is brought out of the controller assembly, so that you can still take advantage of the CA3's temperature sensing and thermal rollback, all with just a single connector and wire to the motor.

Higo 9 pin Motor Plug Pinout

There are downsides to an overmolded plug. You can't measure hall sensor voltages for troubleshooting when it is plugged in, swap phase wires around, or separate the halls from the phase wires to run it sensorless. And replacing damaged connectors is not easy. But for low to medium power ebikes the benefits of this clean single plug are worth it. We have all of our Bafang G01 and Brompton SAW20 motor kits in stock now using this Z910A plug style. And in unusual form, we even finished the user manuals in time for this announcement too. 

20A Grinfineon Manual with Thermistor Pass-Thru  Manual for 20A Grinfineon Controller for Geared Motors with Speed Sensor

Posted By Justin Lemire-Elmore

Just before tipping!Well we managed to have the most crashes in one ride during the cargo bike championships last friday; tip for future events, 2 wheels is better than 3 for fast cornering! Anyways this coming weekend is also packed with with activity, and that includes Grin having a booth both at the inaugural Main Street Bike Expo on Saturday June 10th, and also both Saturday and Sunday at the Vancouver Mini Maker Faire.

At the main street bike expo we'll have a good sampling of converted cargo ebikes, converted Bike Friday and Brompton folders, and some more typical converted commuters on display as well. If you want to learn about retrofits firsthand from us and also check out many other players in the local Vancouver cycling scene all under one roof then this is an event not to miss. It is happeng at the Ellis building on Main St. from 11am - 6pm.

Maker Faire PosterMain Street Bike Expo Poster

Secondly, as is traditional for our Maker Faire presence we've built yet another version of our weight sensing electric longboard. This one is very close to hitting all the marks for an electric skateboard conversion kit using our hands free lean control, including suspension trucks and a ruggedized miniature deck mounted CA. If you want a taste ride on this board in an event full of other creative DIY projects then get your Maker Faire tickets now.

Board BuildingRugged mini CA3 EnclosurePotted dual FOC motor controllers

Posted By Justin Lemire-Elmore

After missing the beat last year we're back to being involved with now the 3rd annual Vancouver Cargo Bike championship this Friday. It's happening once again at the end of Bike to Work Week at Creekside park, only this year there's a dedicated track so less dodging of pedestrians around the seawall bike path.

It's not too late to register and we'll be sponsoring a prize of a $150 (or 15% off an order) gift certificate for anything at Grin to a winner in the e-cargo category. We hope to see many of our customers there and if you've been considering a cargo ebike yourself this would be a great event to check out. We'll be racing our legendary Frankentrike and as always we have a fondness for the homemade and wacky.

Cargo Bike Championship Race MapCargo PosterOur Original Frankentrike, with a 700lb load of drywall scraps. The cargo haul during the race will be a little more forgiving.

Posted By Justin Lemire-Elmore

Hydraulic Stopping Power in your Hands

May 27, 2017 5:12:12 PM PDT

Magura MT4e BrakesWe've been able to add the powerful Magura MT4e hydraulic brake system to our offering of ebike kit accessories. This provides amazing hydraulic stopping power when you need it, with a built-in switch on the lever arm to activate regen or controller cutout.

If you already have hydraulic brakes then the TripWire is a great way to add electric cutoffs to your existing levers. But for those looking to upgrade their ebike from mechanical brakes to hydraulic or building up a new conversion from scratch, these Magura's are among the best.

The brake levers are a symmetric flip-flop design so the same lever works equally well on the left or right handlebar, and come fully bled with 2200mm long hoses. Magura has designed them so that you can then cut the hose to length without the complicated bleeding step if you follow their instructions (See Video Here). The hardware for cutting the hose to length is included with each kit.

Magura Brake Connector Options

We've got them stocked with 180mm disk rotors and various frame caliper adapters to fit this rotor size. For the electrical termination you can choose between a 15cm cable with 2-pin HiGo plug or a longer cable with JST-SM connectors for setups running a V3 Cycle Analyst.

Magura Brake Adapters

Posted By Justin Lemire-Elmore

Ebike parts tend to be lag the standards used in the modern bike industry by several years but we do our best to move things forwards. Recently the 650b aka 27.5" wheel size has largely replaced 26" as the standard for new mountain bikes, but hub motors in 650b rims have been nearly impossible to find. 

650b Rim Size Compared650b Rim Options in Hub Motor BuildsExample of 650b eZee Kit Motor

We've addressed this and now have our front and rear eZee kits available in a prebuilt 27.5" option with a Schwalbe Big Ben tire. We also have stock of both Alex DM24 and and Velocity Cliffhanger rims. We can now offer a 27.5" size for the 9C+ kits, Bafang G01 kits, TDCM IGH kits, and other custom wheel builds. This addition will ensure that Grin has a drop-in hub motor option for all the newer bikes out there.

Posted By Justin Lemire-Elmore

We're new stepping closer to the full release of the V3.1 Cycle Analyst firmware and are smoothing the upgrade process. The Cycle Analyst software suite has been updated to contain the latest 3.1b20 firmware. This latest build is available for Windows, Linux, and Mac. And if you are missing the USB->TTL programming cable, we have that now available on the amazon store too, along along with the digital aux buttons.

Earlier this year we produced a video showcasing the new digital aux input buttons, and have now prepared 4 more short youtube videos highlighting some of the other new features available in the 3.1 firmware, from screen customization to factory resets. Have a look


Video showing the ability to view custom parameters on CA display New Ebrake Options
Youtube video showing the ability to customize what item(s) show up in the main screen. Youtube video showing new ebrake setup menu table, with proportinal regen, logic polarity, and minimum brake time.
Showing and Hiding Display Screens Factory Reset Feature
Video tutorial on selecting and hiding which display screens show up when still or when moving.  Demonstration of the new factory reset feature, where you can restore all of your CA3.1 settings to a factory default state. 
Posted By Justin Lemire-Elmore

Leaps of Joy, Spring Cargo Ebike Sale

March 14, 2017 7:12:23 PM PDT

At last Xtracycle has released the long awaited follow up of their FreeRadical bolt on cargo extenion kit, now called the Xtracycle Leap. It's a full redesign that is cleaner, more rugged, and more versatile than the original, with accomdation for 24" - 29" wheel sizes and a greatly improved frame attachment system.

Xtracycle Leap Views

We've got them in stock both stand alone and as part of a full electric package with a rear geared or direct drive hub motor. And to celebrate their arrival, and cargo ebikes in general, we're having a month long sales event on most of our cargo packages to kick start the season!  This includes:

  25% discount on the great value eZee Expedir bikes  
  (no coupon needed)  
  20% discount on the Yuba Cycle Stoker system   (coupon StokeRight)  
  15% discount on the classic Stokemonkey kit    (coupon StokeLeft)  
  10% discount on the new Leap + Motor kits   (coupon LeapHigh)  
  A free Satiator upgrade wih the Juiced Bikes ODK   (coupon FastCharge)  

To use the coupon codes, you'll need to be logged into our website with an account and then you will have the opportunity to put in the code during checkout. This sale will last until April 15th. 

Cargo Ebikes on Grin Floor
Plus, for local Vancouver customers are selling our floor model Yuba Mundo and 2014 Edgerunner ebikes, both with Cycle Stoker drive systems installed. So if you've been mulling over a cargo ebike purchase for a while but have been a bit leary of the prices, now is the time to drop by our shop for a visit.

Posted By Justin Lemire-Elmore

Vancouver Bike Show LogoWe're used to travelling all around to various trade shows and events but it's been a while since we've had one in our own backyard. This coming weekend Grin will have a booth in the Vancouver Bike Show at the Vancouver Convention Center downtown.

Not only will we be showing off some of the great new Grin products like the LiGo batteries, All Axle hub motor, Tripwire brake cutoffs, Satiators and Phaserunners, and all that, but we're also running a sale on cargo ebikes, including 25% off on brand new eZee Expedirs. There will be floor models to try and both Bike Friday and Brompton folding bike kits built up as well.

If you are into the Bike and/or Outdoor scene in Vancouver, there is a lot going on at the Convention center this weekend so we recommend you register and come for a visit. Our booth is B300 near the Bike Trials Show.

Floor Map of Vancouver Bike Show

UPDATE:  Our first day at the VBS has been really great and we look forwards to meeting many more local Vancouverites on Sunday. There is lots to see and we have some show specials to offer those who visit so it.our little booth.

Aaron at Updated display case booth at VBS 2017 Explaining all the kit options...

Posted By Justin Lemire-Elmore

Introducing the LiGo Batteries

February 21, 2017 1:21:11 AM PST

Last week was a momentous occasion for Grin Technologies, as our innovative LiGo battery modules got ready for primetime. I'll let the video do the talking!

Posted By Justin Lemire-Elmore

Digi Aux Buttons and CA 3.1 Beta

February 10, 2017 11:39:32 AM PST

Our product update and video for this week relates to something close to our hearts, the seemingly timeless Cycle Analyst. While the Version 3.0 CA firmware has been stabilized for some time, our partner Teklektik has been quietly working very hard towards a 3.1 release that fully realizes all of the features we had originally envisioned for this device. One of the best of these is a dual button control input, making on the fly adjustments easier than ever before. Have a look:

Using this requires first updating your Cycle Analyst firmware. The V3.1 beta releases have been published on endless-sphere since last spring, but the latest CA3.1B13 code is getting very close to the final release, and we think it's time fo a wider swath of users to check check it out. You can download it from ES or our CA3 info page, just keep in mind that an upgrade from a 3.0 device will overwrite all of your settings and statistics, so make sure to record those first before reflashing.

Digital Aux Input Buttons

We have the inexpensive dual buttons in stock to ship to anyone wanting to get a head start on this upgrade path for their CA devices. Then in March/April we expect to make the 3.1 firmware our new standard that is preloaded on all the CA3 devices, and we will have a number of video tutorials covering the many other new features.

Posted By Justin Lemire-Elmore

Hailong 36V & 52V Batteries with UN38.3 approval

February 2, 2017 8:56:37 PM PST

We quietly started carrying Hailong downtube mount battery packs last fall, but didn't announce anything as they lacked UN38.3 certification and so were available for local pickup only. Well, that's all changed and we now have a 52V 13Ah downtube battery with UN38.3 documents that we can ship over the world. These battery packs are using the Panasonic GA cells, nominally 3.5Ah each but we'll rate them more conservatively at 3.3Ah.

Hailong Downtube Batteries Frame Bag as Alternate Mount for Downtube Packs
These are great low center of gravity batteries for ebikes running 20-25A motor controllers. The BMS circuit is capable of 40A continuous but usage at these levels isn't recommended for cell longevity. For bikes that don't have suitable waterbottle eyelets on the downtube, we also have sourced a nice Banjo Brothers frame bag that holds them neatly from the toptube, and helps your conversion look less like an ebike with the obvious battery exposed.

Not sure how to pick a battery?

Battery Kits Info PageWe've also recently rewritten our battery kits info page, updating it to reflect our 2017 battery options with summary explanation on choosing the best pack for your setup. 

This updated page also includes tips on parallel or series wiring for connecting batteries and other tidbits that you may find useful when considering a new battery purchase. 

Posted By Justin Lemire-Elmore

This time last year we were deep in the throes of converting and renovating a giant warehouse go become a new home for Grin, in preparation for a lengthy business move we didn't really ask for. And now that we're settled in, it's payoff time and are ready to rock like never before. For the foreseeable future we'll have a new product and/or video announcement to share with you every single week.

We'll start things off by announcing the TripWire, a new product for those looking for an ebrake cutoff solution that tacks onto existing brake levers rather than replacing them. We had tried developing devices based on magnets and reed switches, touch sensitive pads, and other technologies over the years, never quite coming up with a scheme we were happy with. Then out of the blue, one of our customers Tim O'Brien approached us with a solution that was truly great. I'll let Tim explain it himself here:

We've been working with Tim to iron out design details and hare happy to have received his first production batch over the holidays. They're available both with a short cable for plugging into a V3 Cycle Analyst device to enable proportional regen, and with a long cable length to go directly to the controller ebrake input if you don't have a CA3 in your setup.

Posted By Justin Lemire-Elmore

Holiday Hours and Wishes

December 21, 2016 5:07:30 PM PST

Best Wishes from all the us at our staff Christmas party

We wish everyone a splendid holiday season and we'll be busy as usual fulfilling orders and answering questions during the next few weeks, being closed just for the statutory holidays on Christmas and New Years. 

Plus for any real last minute shoppers we've decided to open our doors on Saturday Dec 24th from 11am to 4pm. We just received a fresh stock of beginner unicycles and have tons of Grin goodies to stuff under the tree. 

Posted By Justin Lemire-Elmore