Aprilia_Caponord

Small
Teaser

User login

Random image

Search This Site

Donate to the Kevin Ash Fund

Kevin's funeral was held on Thursday 28th February 2013 and was well attended by family, friends and colleagues.

The Telegraph has very kindly established The Telegraph Kevin Ash Fund to assist with the education of Kevin's three daughters.

If you'd like to make a donation then you can use the PayPal 'Donate' button below which will allow you to donate from your PayPal account, or via credit or debit card. A small percentage (about 3.4%) will be retained by PayPal for the service.

Kevin's family have been touched by the generosity and messages of support from people using the website and would like to express their gratitude to those who have contributed in any way.

The donations keep coming in, thank you so much, and the family especially like it when you leave a message.

Recent Articles

Sensor and sensibility

We're familiar with solid-state electronics in biking. Ignition swapped points for transistors in the 1970s, then went digital in the 1990s. Now, the need for greater power, fuel efficiency and emissions control means modern engines only work with computer-controlled fuelling, ignition, combustion and exhaust. When we open the throttle we pull the strings, but the ECU calls the shots. To do it, the ECU needs an accurate view of the world. And it gets it through its sensors.

Putting gyroscopes under the microscope

A gyroscope is a rigid circular or spherical mass rotating around an axis and for over 100 years motorcycles have come with three of them: a front wheel, a rear wheel and a crank (if you're being pedantic you could include cams, balancer shafts, gearbox, clutch etc). The classic mechanical model of a gyroscope ranges from the very small – electrons spinning around an atom's nucleus – to the very large – the Earth.

Naturally self-centring

Most of us have an innate feel for balancing a high centre of gravity on a relatively short wheelbase. Say, like a motorbike. Its centre of gravity is the point at which the sum of the surrounding mass is zero, and is largely determined by the location of the engine, the heaviest part of the package. Usually the CoG is midway between the wheels (half the wheelbase) and 60 to 75cm off the ground; just above the engine, in front of your knees. Or at least it is until you get on.

Giving me good vibrations

Anyone with fingers knows bikes vibrate, sometimes strongly enough to make picking your nose impossible. But how we perceive vibration depends on its type, pattern, frequency and cause. Bikes are subject to different types of vibration. A bumpy road creates random forced vibration at medium to high frequency (around 5-35 Hz depending on vehicle speed). It's perceived as unpleasant, as is head buffeting caused by wind turbulence. Engineers and aerodynamicists try to minimise these bad vibrations. But we usually talk about engine vibration. There are many sources...

Pressure is good for character

From the launch of Yamaha's new Super Ténéré: "The exhaust pipe connection between the two headers is discontinued to give more character to the engine. The link pipe gives a flat feeling to the curve, so removing it makes the engine a bit more peaky." This is all about exhaust gas. When a four-stroke is tuned for power it means more revs, and so the cylinders have thousandths of second to fill with fresh mixture, compress it, burn it and pump it out again. To get enough mixture in and out, inlet valves open early and exhaust valves stay open for longer – so both are open at the same time.