An original idea from concept to coronavirus.

I am often asked, “Where do you get your ideas from?”  Well, it may surprise you to know that they mostly come from our customers, in other words, from you!

Because people know we innovate and are always interested in new ideas, we get asked to look at all kinds of problems.  Almost all Tomcat innovations begin this way, and that’s certainly true of our latest innovation, the “Bionic Buddy”.

My judgement is that Bionic Buddy will be an absolute game-changer for lots of Tomcat trike owners, both past and present, and I thought you might like to know how it all came about!

Bath is beautiful, but….!

It all started with a customer in Bath whose granddaughter has special needs.  He told us she just loves to ride her new Tomcat, and he loves to take her, but there was a problem.  Some streets in Bath are like the north face of the Eiger… well maybe that’s a slight exaggeration, but you know what I mean!  Certainly “one in four” hills are not uncommon.

Granddad called me shortly after receiving his trike and told me of the double whammy!  Not only were all the hills on the way home, but both were tired by then… happy, but tired.  His not unreasonable question was “Can you put an electric drive on my granddaughters’ trike?”

I’ve been asked that question many times before, but I’d always rejected it on the grounds that fitting a power drive to a carer controlled trike has significant safety issues, therefore the usual bicycle power assist (with its sixteen miles per hour top speed) was totally out of the question.

As chance so often has it, I was asked the same question just a few days later so I promised to give it some thought.  There are ‘clip-on’ wheelchair drives out there that are limited to the legal limit of 4mph, but they are either very heavy, impossible to mount on a trike, or feasible, but silly expensive.

A new idea was needed!

I was considering designing our own drive along conventional lines when out of the blue, the manufacturer of our Bullet and Rotor drives, came out with a 4mph ‘motor within a wheel’.  It made for a very compact and lightweight design indeed!  It looked very interesting and suddenly granddad’s idea had possibilities!

I called both customers and both wanted to order there and then.  I said, “Look, this has never been done before on a trike!  There are lots of gubbins getting in the way of a conventional wheelchair drive arrangement, like brake discs, bearings, sprockets, chain drives and differential gearboxes, all of them in exactly the location I need to put the drive wheel!  It could take 6 months of development, maybe more!”.  It didn’t matter, they both wanted it, whilst granddad wanted to pay upfront to gee me along a bit!  If I had any worries about popularity, I had my answer.

Technical Challenges.

It turned out I wasn’t wrong about the gubbins!  I won’t get technical here, but to avoid scuffing on corners, any drive wheel not on a swinging arm, needs to be mounted centrally between the rear wheels, but there is no space available in that location on a trike, and even a swinging arm has serious deficiencies where mounting is concerned.

Original Concept

The trouble with designing something original is that you rarely have a steer to get you started.  Your computer screen is blank and stays that way until you get a breakthrough idea.  If it’s the wrong idea, you can be on a wild goose chase for months and this project had a goosey feel about it!

Back to granddad and my lovely lady in Wales with a few questions!  I needed to know how they would use what was to become the ‘Bionic Buddy’…? Would it be used all the time, most of the time, or just occasionally… perhaps as a safety net during seizures etc?  Would it be permanently attached, or must it be removable?  Would it be rider controlled, or carer controlled, and what extra weight was acceptable?

All these questions were relevant, and both customers had different priorities, but the general consensus was for an easily detachable, easily transportable, “On-Off” drive, that was lightweight to carry, but with plenty of hill-climbing power.  Last of all… one wanted Carer Control™ by the carer, whilst the other wanted independent control by the rider, so no challenges there then!

I did what I usually do in these circumstances, which is nothing at all until I have a workable idea, but I do think about it in the car or at other odd times, and sooner or later the penny will drop.

Resolving the Challenges.

By using the ‘motor in a wheel’ concept, we’d immediately sorted the weight problem, because the estimated additional weight was only 6kg, as opposed to 12kg for a conventional wheelchair drive.  That simultaneously made an easily removable system feasible, as 6kg is very manageable; but where to ‘lock-on’ to the trike was the question, and where to position the ‘wheel motor’ was another…!

Two ideas gave me a breakthrough.  Firstly, if it wasn’t possible to have the wheel-motor driving on the road in a conventional way, then let it drive on the trike wheels instead!  Secondly, if we couldn’t mount the wheel motor or its bracketry between the wheels, then maybe I could design, quick release latches for the basket brackets we fit most Tomcats.  This second idea was really exciting because it meant we could retrofit a Bionic Buddy to almost every Tomcat built since September 2016!


Design done, I thought the prototype would be a great project for the apprentice who then did all the machining and electronics connectivity and it was, as it always is, rewarding to see a young engineer in the making, using his hands and brain to achieve something unique and innovative.

There were aspects of the design that I really wasn’t sure would work, mostly centred around the friction between the motor wheel and the trike wheel.  Friction between the two was designed to increase as the workload increased and vice versa, but I was far from sure we would get that feature right first time.

Road Testing.

With the retrofitting of the latches on the basket carrier brackets working well and the power drive and the quick release latching mechanism all working well, it was time to find a crash test dummy.  The apprentice was first, followed by just about all the engineers in turn and culminating with Kevin, our much-loved rep for the West and South.  Kevin is touching 15 stone and though we knew it worked on flat ground, I wanted to see how Bionic Buddy would work on a steep slope – and more to the point – if it would pull away on a steep slope…!

The slope in question was 1 in 5 and not only did Bionic Buddy pull away, it did it with ease, much to everyone’s excitement, but I was most pleased to see how the friction mechanism adjusted itself to give a smooth and slip-free start and impressive acceleration up such a challenging slope.  I can’t claim that we got everything right first time as there were a few things to adjust, but all in all, it was a great success.

Of course, that is not all the story when getting a product to market is concerned, and complex issues of snagging, testing and certification, production tooling, manuals and marketing all must follow, but we are ready now and production has already started.

A great time to introduce this Innovation. 

This is a tough time for anyone coping with a disability, let alone children, who struggle to understand why life has changed so much and so quickly, and for many, the coronavirus will cause stress and anxiety for weeks to come.   For that reason, a Tomcat will become a lifeline for many families during this difficult time, giving them an opportunity to take long rides in the fresh air and sunshine. 

But not all families with a Tomcat can take advantage of its full “long ride” potential because of hills and dales, the rider’s health considerations, or who is available to supervise them.  Bionic Buddy solves all of those issues by taking the hard work out of pedalling and eliminating pushing altogether. Whatever the problem, Bionic buddy can get you there and back – effortlessly!


I hope you have enjoyed this story about how a need turns to an idea, and then a reality.  We have done this many times before, but this is the first time I have thought to tell you about it.  Why this time?  Well, I think Bionic Buddy will bring a bit of cheer to the most difficult time in living memory for our disabled community, and perhaps because battery vehicles are the thing of the future and we love to be the future!

Bob Griffin, M.D. Tomcat SNI Ltd.

For more information or to order a Bionic Buddy…

If you would like more information about retrofitting a Bionic Buddy to your existing trike or adding Bionic Buddy to your current order, please give us a call on 01452 616900 or email  For most customers, the lead time will be four weeks and the cost will be £1243.00

Bionic Buddy main features and benefits.

  • Retrofits to most Tomcats built after September 2016.
  • Can be easily fitted by the customer.
  • Ideally suited for use in hilly regions or difficult terrain.
  • Ideally suited to limited strength, stamina, heart weakness or degenerative conditions.
  • Works without the rider pedalling.
  • Can be engaged or disengaged by the carer, during the trip.
  • Can be easily removed when not required.
  • Twist grip throttle control.
  • Tomcat onsite or RTB retrofitting service available. (chargeable).
  • Approximate 12-mile range on a full battery charge.
  • Lightweight Construction.
Tomcat “Bionic Buddy” Data Sheet.
Motor Power 250watts
Motor Volts 36v
Battery Power 2.9Ah
Battery Charge Level Indicator? Yes
Battery Safety Fuse 15amps
Battery Charge Volts 42v
Battery Charge Time 2.1 hours
Battery Safety Lock Yes
Battery Removable? Yes
Charge on Vehicle? Yes
Battery Lock? Yes
Speed Control Type Twist Throttle
Road Speed (All trike models) 0 – 4mph (0 -6kph) variable
“On-Off” drive engagement function Manual by carer.
Detachment By Quick Release latches
Total “on Vehicle” Weight 6kg
Off Vehicle Weight (with battery) 4kg
Battery Weight 1.5g
Off Vehicle dimensions 58cm x 35cm x 15cm
Warranty 5 years Mechanical, 18 months Electrical components.

*Retrofit Requirements and restrictions.

Not available for Tiger or Tamara models.
Requires Tomcats Dual axle.  (Dual Axle can usually be retrofitted)
Bionic Buddy, MUST be controlled by the carer only, on Carer Controlled™ trikes.