Drive Systems & Gear Changing

Dual Drive

A Tomcat Dual Drive™ swaps a single speed drive between fixed and freewheeling by the operating a small lever and was originally designed as an essential feature of a Tomcat Trailer Trike™ system.

Some riders do best with a fixed drive tricycle; however a free wheel drive is essential whenever a trike is converted to a trailer. Without the Dual Drive™ system a trailer and tricycle would need to be provided as two entirely separate items of equipment, so it was an important feature of the Trailer Trike™ invention.

However, we then found many other good reasons to fit a Dual Drive on “Stand alone” trikes, such as:

  • Rider’s who tire easily, could swap to “Free Wheel Drive” and be pushed home.
  • Ditto Riders prone to unpredictable fits.
  • Children who need a fixed drive but might well progress to a free wheel drive.
  • Trikes that might be upgraded to a trailer at a later date.
  • Schools and other centres where children with wide ranging abilities use the same equipment.
  • Export sales.

The first Dual Drive™ was designed for Keith McKaig, then built to order until being standardised and put on the “options” list in 2004.

Integrated Multi Geared Drive™  

There’s a well known saying that say’s; ”Simplicity is efficiency” and it’s true. Another lesser known saying (the writers) says “It’s simple to make something complex, but complex to make something simple”. That’s true too, but who cares.

If you compared a Tomcat geared trike transmission – perhaps on a Road Hog – with a geared trike transmission from any other source, you might think you were getting more for your money with the other manufacturer, and if you were after, more weight, more friction, more adjuster mechanisms, more chains to lubricate, more maintenance to do and more things to go wrong, you’d be bang on right first time and here’s why!

A conventional arrangement has:

  • 2 drive chains whilst a Tomcat has 1.
  • And 4 drive sprockets whilst a Tomcat has only 2
  • An intermediate lay-shaft complete with bracket and adjuster whilst a Tomcat has none
  • 2 chain tensioning mechanisms whilst a Tomcat has only 1
  • And 2 Chain guards whilst a Tomcat has just 1
  • A drive friction loss of up to 15% whilst a Tomcat is less than 8%
  • And 6 bearings in the system, whilst a Tomcat has just 4

The reason for all the paraphernalia on a conventional arrangement is that cycle gear mechanisms – both hub and derailleur – are designed for bicycles, where they are at the centre of the wheel which is then mounted between two forks. This is not possible on a tricycle because the wheel is offset from the chain drive and is driven by a long shaft. Consequently conventional arrangements have a special bracket halfway, with the gear mechanism mounted on it. It’s driven by a chain and it in turn, drives the axle through another chain. Each chain drive creates friction. Its parts add weight; it needs a guard, brackets and a tension adjuster, and there are twice as many things to go wrong.

We built the first Tomcats this way, but quickly fell out of love with such an unnecessarily heavy, sluggish, maintenance prone system because they are all the things that riders with special needs should avoid. We wanted “lightweight, efficient and reliable” and the only way to achieve that was by integrating the hub into the axle itself.

Manufacturing our own hubs would be impractical so we have 5 and 8 speed hubs by one of the world’s leading names, manufactured to Tomcats own design. The result is a lighter, faster more reliable machine that weighs in less than many modern bicycles. Its engineering quality, not quantity, and it really does make a difference.

Tomcats Integrated Multi Geared Drive™ is compatible with the Tomcat Make and Break™ system.

Make and Break™ Gear-change System

The Tomcat “Make and Break” gear-change system is a pretty pointless invention on its own, but build it into a multi geared trike, (or better still a multi geared Trailer Trike™) and suddenly you own the most transportable cycle on planet earth.

One great Tomcat feature is the trikes ability to split into two pieces which it does with impressive speed and simplicity. Problems only arise when you want to split a multi geared trike or “Trailer Trike” in two, because what happens to the gear change cable that joins the two parts? It’s a tricky one alright!

A few manufacturers get over the problem by having a detachable end to the handlebar and we tried that too, but it’s a poor idea because it’s so easy to kink, stretch or snag the loose cable.

We solved the problem with the “Make and Break” system (which is really two cables; one on each part), which connect and disconnect automatically, when the parts are assembled or disassembled.

Tomcats “Make and Break” has proved itself to be a highly reliable system, but even if it does misalign on assembly all you do is move the shift to gear 5 and it resets. Life’s too short to be unscrewing bits of handlebar we think.

Dual Fixed and Free Wheeling Drive

Drive can swap between fixed and free-wheel drive with one button. Essential as part of a Trailer/Trike combination and can be extremely useful for tiredness or fits.

©2017 Tomcat Special Needs Innovations Ltd. --- All Rights Reserved