Tested: Dual Clutch Transmission
Tue, 18 Sep 2012Been blasting all around the UK on my Crosstourer DCT this summer.
The bike is mega in a Range Rovery-posh and grunty kind of a way. But it’s that engine and gearbox that transcend the normal into new realms of brilliance.
I’ve been doing my best not to bore people too much about DCT but it’s hard. I’m now becoming more aware of people’s glazed expressions and blatant yawning and watch-gazing.
Oh, is that the time?
I keep hearing well-founded rumours about Honda’s 2014 V-4 Fireblade (launched at the end of 2013 it would seem) and I just hope and pray that it’s going to be available with DCT. A V-4, 1000cc Fireblade with DCT would be better than awesome. Be nice if it had a conventional gear-lever as well as flappy paddles.
But before all you start typing furious replies calling me a blathering twunt and telling me that gear-changing is all part of your motorcycling enjoyment and it’s what your left hand and foot are for – their sole purpose in life. Let me have my say.
It’s a funny choice to put DCT on Crosstourer and VFR1200, if you ask me. That NC700 thing, you know the one? The one that uses half a Honda Jazz engine and is aimed at making biking easier for newcomers? Well I can see the logic there. There’s nothing simpler than twist-and-go and for a newcomer with rudimentary clutch and mechanical skills, DCT is perfect here.
But it’s a system that would be best suited to an all-out sportsbike, I think.
DCT seems to have stood the test of time. I’ve spent the last two months trying to out-fox the Crosstourer’s DCT gearbox and failed, miserably. It’s a bit of a personal challenge. I mean how dare a piece of technology change gear faster and smoother than I can after almost exactly forty years riding bikes? I really want it to fail.
The other day, riding to Cardiff, I thought (almost with glee) that I’d finally caught it throwing a wobbly. Sixth gear, outside lane of the A1 and for no reason the revs start screaming and the LCD gear indicator informs me I’m in fourth gear. For the next few miles I messed about with the right hand rocker button, switching from manual to sport to normal. I couldn’t make it do again.
Until twenty miles later. It was then (when it happened again) I realized the carbon knuckle guard on the thumb of my left-hand glove was slightly catching the down-shift flappy paddle. Furious replies calling me a twunt are well founded.
It’s true, low-speed u-turns require very, very precise throttle inputs. It’s also true that the noise DCT makes on low gear up-shifts sounds like the opening credits of Porridge. Some of this clonking, I think, is dog engagement and the other clanks and clunks are the backlash in the shaft final drive assembly. To be absolutely sure it’d be nice to try DCT with a chain final drive. Like on the new V-4 Fireblade, perhaps…
But it’s not just novice-friendly, it’s when you’re getting a real move-on that the DCT is in its prime.
When I first rode the finished prototype version in Japan nearly three years ago, it was in ridiculously fast and loose circumstances. We got about twenty minutes on a new VFR1200 DCT chasing a Japanese ex 250GP rider around Sugo circuit’s perimeter roads. Maximum attack didn’t even come into it.
It was like being told to learn a circuit and qualify on pole all at once.
I don’t think Honda contrived it this way, after all, it was just a nutter on a bike trying to humble a load of journalists. But it showcased perfectly what DCT could do for a rider in a hurry with lots already to think about.
It’s not until you’re really pushing the bike hard that DCT’s brilliance shines through. And that’s what confuses me. The Crosstourrer is hardly built for scratching on track days, is it?
The DCT ace card is how it manages to keep the bike settled in corners that require serious acceleration out of.
The best track examples I can think of are the exit of Coppice at Donington, Charlies 2 at Cadwell and Gerrards and Devils Elbow at Mallory. All corners where you’re simultaneously piling on the coals and kicking up through the gears as your velocity increases. Glen Helen on the IOM TT course is another good road-based example.
Because the DCT system doesn’t require you to shut the throttle for it to up-shift, there’s no weight transference front to rear. Just a farty noise from the tailpipe as the ignition cuts briefly and a drop in revs let you know that the next gear has engaged. This predictable fore and aft weight bias is massively useful when you’re already asking everything from the edges of your tyres. In these situations, predictability is king.
On the road, the same applies to exiting wet, greasy roundabout or tackling short motorway slip roads. I don’t care if your clutch control makes Dougie Lampkin look ham-fisted, there’s no way you could replicate this fast-shifting smoothness manually. We’re talking up-shifts measure in thousandths of a second. With the throttle open and the back wheel driving.
Want to shortshift early? Fine. Just tap the up paddle (where the headlight flasher usually is). Want to back-shift hard enough to use some serious engine braking? Juts hit the other paddle on the front of the instrument cluster to engage a lower cog when you choose (and the revs blip to match road and engine speed).
It’s all the best things about a quick-shifter and more because it’s faster as the twin clutch system allows the pre-engagement of the next gear. It’s no coincidence that the factory MotoGP Repsol Hondas use an evolution of this pre-engagement system. Have you seen how fast Alberto Puig’s surrogate son is out of turns? That’s not just because he’s so small. That's a very clever gearbox.
Forget race tracks for a minute, though. Real World, the DCT system has another distinct advantage, especially when you’re a bit kackered after a whole day in the saddle.
Because you’re not thinking about gear-shifting and balancing clutch and throttle you’ve got plenty of time to think about other, more important things. Just like when I was chasing a crazed test rider around Sugo’s access roads, it frees up your brain to think about apexes, braking points and surface changes. Or end of year tax returns, if that’s how you roll.
No. I’m sold. I think DCT is the most important technical advancement for mortorbikes since arrival of the acetylene headlamp. Or something.
Sorry, was I boring you?
By mark forsyth
See also: Rumored 2013 Honda CBR500, CB500 Captured in Spy Photos, VP of American Honda Motorcycles Division, Ray Blank, to Retire in October 2012, Miguel Duhamel to Ride for Lightning-Barracuda at Le Mans FIM e-Power/TTXGP Race.