LATEST TEST AND FEATURES...

* The most recent bike tests and features are listed below.

Compounding: The Problem

Ever wondered why your rear tyre wears down in the middle but not at the sides? It’s safer that way...

At first glance there’s nothing in common between touring on a Triumph Tiger 800 XC and a 250bhp MotoGP prototype. But there is.

I recently had a 3000-mile ride on a Tiger. Its Bridgestone Battlewings were 4000 miles-old at the start and, as you’d expect, the rear squared-off as the ride went on. 7000 miles isn’t a bad total, and the bike maintained its steering and stability. But eventually it shimmied a bit over white-lines as it rolled across its squared-off centre. And with plenty of tread left on the edges, it seemed a waste of rubber to chuck it away.

So why don’t manufacturers make rear tyres harder in the middle where they wear the most?...

Fuelling about with maps

Selecting a power mode on your bike? The future’s already been mapped out. Literally.

Fitting a litre sportsbike with a castrating low power engine mode sounds like a bad idea, even if you call it ‘Rain’ mode. And few electronic aids are as contentious because engine modes are, technically, voluntary restrictions. Each is, broadly speaking, an overlay of instructions directing the ECU to manipulate and reduce engine performance.

But what actually happens when you push that button...?

Moto Guzzi V7 Stone Review

Moto Guzzi V7 1

If ever a company has been through rough times, then surely Moto Guzzi has to be a contender for the role of ultimate survivor. In spite of so many obstacles over the years it is still churning out bikes and is today’s oldest brand of European motorcycle manufacturer with continuous production. A legacy of bad management, circumstance and I have no doubt also bad luck, has seen it diminish in size from its heyday down to a true minority player. In 2004 it was taken over...

Playing the frame game

Frames have got uglier and cheaper, but they’re straighter than ever. Suspension, on the other hand...

Last week’s Techwatch talked about how current production engines have close tolerances and matched components, and how automated mass-production reduces variability. If a modern engine makes 100bhp today, in 12 months’ time it’s likely the same model will also make 100bhp (although early BMW S1000RRs were an exception – bikes varied by up to 15bhp, and no-one knows why....

Putting up with intolerance

Sometimes the worse something fits, the better it works...

It’s long been a biking myth that in Japanese engine assembly plants, female workers are preferred to males for some jobs on the production line because they have smaller hands and greater dexterity. Having spent time at Suzuki’s vast Takatsuka Engine Plant in Hamamatsu, I can safely put that one to rest; it’s not true. They have plenty of both on the production lines.

But while I was there I saw something else intriguing:...

Swingarms and (bumpy) roundabouts

Ducati’s Panigale 1199 has a single-sided swingarm. The new 899 has a double sided swingarm. Now that’s a good idea...

It’s intuitive to grip a wheel at the end of each axle to give yourself maximum control of stability and alignment (or, if we’re talking about front wheels, steering). It’s certainly easier – it’s more effort to play wheelbarrows if you only using one arm to hold the barrow wheel. But it also looks cool if you wave with your free hand.

And so it is with swingarms:...

Variable Rates Of Interest

Variable valve timing: meet the engine technology that just won’t go away

In the list of pointless engine gimmicks, you’d surely put variable valve timing at number one. Only three production bikes have automatic VVT: Honda’s VFR800 VTEC (crude, two-stage system), Kawasaki’s 1400GTR (more sophisticated but barely noticeable) and, between 1991 and 1998, Suzuki’s Japan-only R-version 250 and 400 Bandits (crude and unnoticeable). And all of them gimmicks.

So what is VVT, and why do we keep hearing about it?...

Fins ain’t what they used to be

Why air-cooled bikes are having a water-cooler moment

In the news of their 2014 Touring range upgrades, Harley-Davidson smuggled a phrase rarely associated with the Milwaukee ironmongers (VRods aside): liquid-cooling. Before purists protest, Harley limit the ‘Twin-Cooled’ engines to four top-end models: the Ultra Limited, Electra Glide, Ultra Classic and Tri Glide trike. Which isn’t even a bike. But then it’s not really liquid-cooling either.

It’s fair to say the 45° V-twin has never enjoyed a reputation for cutting-edge tech; Harley are reputed to employ more designers than engineers.

But it’s also unfair to say. Designing a Harley engine might not be as challenging as building a 250bhp MotoGP engine that does 26 laps on 21 litres of fuel. But making an air-cooled motor sound and feel true to the Harley archetype yet meet stringent noise and emissions regulations is a challenge nonetheless.

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