Roller-drive 750W front wheel widget mounts on docking bracket

Many of the world’s bike share schemes — like London’s Boris Bikes — use identical bikes and docking technology from Canadian company Bixi. That gave inventor Jeff Guida from New York a simple idea: why not bolt an electric motor to a Bixi bike and turn it into an e-bike?

The result of eight months’ development is the ShareRoller, an electric-assist motor that mounts on the bike’s triangular docking bracket and drives the front wheel. ShareRoller puts out a whopping 750 Watts in its US incarnation though UK and Canada versions will be power-limited to keep them legal. Or somewhat legal. Maybe. But we’ll get to that in a moment.

First, though, Jeff's looking for $100,000 to get the ShareRoller into production, and, almost inevitably, he's turned to Kickstarter to do it.

Here's his fund-raising video:

On the device’s Kickstarter page, Jeff says something that will resonate with everyone who’s ridden a Boris Bike: “The idea for ShareRoller was initially conceived in June 2013, right after CitiBike launched in NYC. One ride on the 45-lb 3-speed bikes was enough to spur the search for motor assistance.”

Boris Bikes. You can’t damage them, but at least they’re heavy.

So Jeff “abducted” a bike, and had the ‘Aha!’ idea of mounting a motor on the docking bracket. After multiple rounds of design and prototyping, the result is a briefcase-sized assembly of motor, batteries and drive roller that will propel a bike at 18mph without pedalling for 12 miles with the standard battery and 20 miles with the extended-range battery.

ShareRoller charges in 1.5 to 2 hours and uses batteries from the same company that supplies electric car maker Tesla. It’s about the size of a ream of A4 printer paper and weighs 6-7 pounds. That may be less ‘portable’ and more ‘luggable’ but if you live and work close to docking stations it’s not going to kill you.

Unlike many Kickstarters, this isn’t a rough proto and a bunch of CAD drawings. Jeff says the ShareRoller is a “fully-developed, late-stage pre-production product”.

Jeff worked in management consulting and finance before turning his hand to inventing, but studied electrical engineering in college. But what’s enabled the ShareRoller to go from idea to production-ready so quickly is a technology that’s turning many industries on their heads: 3D printing.

"Years ago, I would've needed a giant engineering company and several million dollars in development research and it still would've taken two years or more," Jeff told Gizmodo.

A $20,000 investment ina 3D printer allowed him to “hyper-drive the design-prototype-test-redesign loop”.

“We could have spent that $20k on a snazzy video instead, but we felt this was a much better use of our limited funds,” he says on his Kickstarter page.

ShareRoller won't just be for use on Boris Bike-style hire cycles. After all, there are only a bit of 20,000 of them in the world. Jeff already has prototype mounts that will fit a kick-scooter and a Brompton, and plans to expand ShareRoller's application to a wide range of bikes.

The idea of jumping on a Boris Bike and getting from A to B at 18mph, instead of the more sedate pace the bikes usually mandate might sound appealing, but there are a few possible snags for UK use.

For start, electric bikes here have to be pedal-assist. If all the motive power comes from the motor, then it’s a motorbike and you need a helmet, licence, registration and all the other regulatory gubbins intended to keep petrolheads in check.

New York has similar rules and Jeff aims to get round them by preventing the ShareRoller from working if you’re stationary. You have to pedal away before the power kicks in. But there doesn’t seem to be any way for ShareRoller to tell whether or not you’re still pedalling once you’re under way.

Then there’s the power. In the UK electrically assisted pedal cycles — to give them their official designation — are limited to 200 watts, which the ShareRoller’s 750 watts clearly exceeds, and the electric assist has to cut out at 15mph.

A ShareRoller that puts out just 200 watts might be a bit anaemic away from the lights but the power restriction should massively extend the range (and its acceleration will still be no worse than most cyclists and a lot quicker than an unassisted Boris Bike). You might not cover the 12 miles from the eastern edge of the Boris Bike network at East India to the western at Ravenscourt Park in a single 30 minute hire slot, but you should have enough juice for the return journey.

You'll have to keep an eye out for TfL staff, though, in case they decide to enfore the rule that users may not "add or attach accessories or trailers to the cycle."

Our official grumpy Northerner, John has been riding bikes for over 30 years since discovering as an uncoordinated teen that a sport could be fun if it didn't require you to catch a ball or get in the way of a hulking prop forward.

Road touring was followed by mountain biking and a career racing in the mud that was as brief as it was unsuccessful.

Somewhere along the line came the discovery that he could string a few words together, followed by the even more remarkable discovery that people were mug enough to pay for this rather than expecting him to do an honest day's work. He's pretty certain he's worked for even more bike publications than Mat Brett.

The inevitable 30-something MAMIL transition saw him shift to skinny tyres and these days he lives in Cambridge where the lack of hills is more than made up for by the headwinds.


Paul_C [500 posts] 3 years ago

that thing is going to shred the tires... and 750W!!!! eeek!!! The take-off I get with my 250W eBike is scary enough if not expected... I have to remember to turn the assist off when negotiating chicanes and pig-pens...

Needs a better way of getting the traction onto the wheel without shredding the tires... the old Sinclair ZETA had a better method using a belt to increase the contact area.

georgee [177 posts] 3 years ago

Exceptionally useful idea, why not also contribute to my Kickstarter campaign for a revolutionary chocolate fireguard or cheese bicycle, i'm also after initial seed funding for my new screen door manufacturer with specific naval uses, I see them on submarines being a big growth market.

jarredscycling [456 posts] 3 years ago

How exactly could the TFL enforce the no accessories rule? I mean they aren't exactly going to be able to flag you down as you speed by at 18mph with your electric motor

crazy-legs [881 posts] 3 years ago

There used to be something very similar that you could buy aftermarket - 15 years ago or more.
I remember a guy bringing one into the bike shop I worked at and asking us to fit it. It was comprehensively shit in every possible way; battery life measured in minutes, weight measured in tons and power measured in microwatts. The belt drive also kept slipping on the tyre, especially if it was wet.

hampstead_bandit [614 posts] 3 years ago

Can I make a correction to the article?

"Many of the world’s bike share schemes — like London’s Boris Bikes — use identical bikes and docking technology from Canadian company Bixi."

The bikes are actually made in Quebec by Canadian manufacturer 'Devinci' who are well known in the mountain bike world for their full suspension downhill and trail bikes - they currently sponsor the downhill world champion Stevie Smith


I used to work for the Devinci UK distributor in the UK, and was asked to provide technical support to SERCO before the scheme went "live" as they were having some technical issues with their Bixi bike assembly.

Here is my old 'Devinci Hectik' slotted into a London Bike Hire Scheme docking station shortly before Serco did their first installations "live" to the London streets.


Gkam84 [9100 posts] 3 years ago

The law is VERY foggy when it comes to electric bikes.

While the UK law is 200w and 15mph

EU law is 250w and 25km/h so 15.5mph

Then you get into tandems and tricycles UK - 250w and EU - 300w

They you get into the weight restrictions...

750w obviously is more than all of the laws, but that only applies to on road use.

Neil753 [447 posts] 3 years ago
hsam [8 posts] 3 years ago

When does a bicycle stop being a bicycle?