Ok, what's quicker off the mark ...

I rode my mate's SV thou the other day, but it didn't feel very sharp
on acceleration, so I open the question to the assembled masses,
what's quicker off the mark, an inline four (such as my beloved) or a
V Twin.

Are SV thou's particularly slow, would a differnnt configuration
engine feel faster, e.g that of a duke ?

Same with a firestorm really, they take a bit of time to limber up
too. Would you need to upgrade to an SP2 or equivalent to get the same
sort of 0-60 time.

Or would the 0-60's be largely irrelevant once the Vtwin torque kicks
in ? are they only sluggish for the first few feet until the engine
comes on to the cam.

Any pointers appreciated as I have a bit of a non 4 cyl bikes cherry
;-)

Cheers,

Paul.

 

Zymurgy says...

OK I've got a few minutes to spare so here's my 2p's worth.

How quick a bike feels off the mark is a very subjective thing. My tuned
RD500 felt much faster than my CBR though I doubt it actually was. The
combination of a short(ish) wheelbase and peaky motor made for exciting
takeoffs where as the CBR with a long wheelbase and flatter power curve
just drives off the line without the wheele,bog down, wheele again antics
of the RD.

As for which is really faster its down to torque,gearing, wheelbase and
grip. How many cylinders is pretty irrelevant, although twins are
normally easier on the tyres than 4's due to their longer firing
intervals.

 

I thought the exact opposite was true...

 

nope

 

you know, almost as soon as I posted that, I realised I was talking
shite.

However, and I'll stand by this one - IME, twins (and singles to an
even greater extent) are more likely to spin up the back wheel in the
wet in a straight line. Probably because of the power pulses. This
might have been what I was thinking of when I made the other post.

Anyway, off to the pub...

 

Hmmm ...

Champ will be along in a minute ...

 

darsy wrote

Half the speed twice the fun. It works on many levels.

 

Well, I found the opposite. The XBR500 almost never span the back wheel
under hard acceleration. The CB500 slightly, depending on the road
surface. Whereas the Fazer often does.

 

Compares some bikes along with cage - quite interesting, especially if your
bike/cage is in there:

http://www.syclone.freeserve.co.uk/rivals.htm

Kev

 

I really don't know, perhaps the twin has better drive.

Those little twist and go thingies are very quick off the mark, say up
to 15 or 20mph then they run out of steam.

Don't know.

I think there are so many variables at play it would be very difficult
to say. Things like tyres, tarmac and pilot all play critical roles.
One pilot may be better at launching a twin another may be better on a
four.

The 0-60 is over in a flash, I would hate to try to measure it on my
gixxer.

You're not kidding are you.

 

Kevin Seal wrote

Mine did.

I suspect though that you and I may have different definitions of hard
acceleration.

 

bugger. mine isn't.

So a bandit 6, 70bhp, does a quarter mile in 12.7 seconds.
now I really want to know what my 12 with it's extras will do.

 

Doesn't matter - it's all down to gearing, power and torque.

I doubt SV thous are slow, but probably tuned (or detuned)
for better midrange than something like the Honda SP1/2 RC51.
The FireStorm probably sits below the SV in terms of "quick
off the mark".

Big v-twins have big pistons, flywheels and heavy clutches
to spin up, so they do tend to feel a lot more lumpy than
a nice light inline 4, but the lower down torque tends to
make up for this. Probably not much in it for 0-60 and most
of the difference can be sorted by changing the gearing
anyway.

And yes, you really should have a go on mine ;-)

 

and how much experience of riding big singles and twins in the wet
does Champ have, then?

Seriously - my SZR used to spin the rear up in the wet just by mildly
opening the throttle. In fact, I just to be able to rear wheel steer
the thing in the wet, before I read in a magazine that only riding
gods could do that, and then I lost all confidence in doing it.

 

Oh I don't know....

(It's a shame that modern bikes have a rev limiter!)

 

And Yamaha have done this with the M1 this year. Its still an inline 4
but has a grouped firing sequence to make it deliver its power more
like a twin.

 

Having raced both inline 4's (CBR600) and V-Twins (Aprilia RSVR) I
have quite a bit of experience doing standing starts on both. I think,
if you're talking 0-60 times (although quite why this is important I
dont know) I'd say it really comes down to the rider's skill &
technique. I personally found the 600 easier to get a good launch -
the big V-Twin was always a battle between drive & wheelies. Most big
bikes will do more then 60 in first so it really all comes down to how
well you can launch it off the line.

On the 600 I found I got the best launches if I held a steady 8000rpm
on the line (ie no blipping) then hit the throttle and slipped the
clutch on the launch and held about 9-10000rpm until I could disengage
the clutch fully then its simply nailed throttle until the redline.

On the twin its similar but less revs on the line (5000) and being
more careful with the clutch to avoid wheelies. Much trickier I found.

Havent a clue what you're on about there.

Well, if the engine is sluggish in the lower revs, you slip the clutch
on the launch to avoid it. Doh!

Practice.

 

The one with the best power to weight ratio

SV Thous are slow.

There's no such thing as "v twin torque". Twins do tend to have a
lower red line than equivalent fours, and so make their power and
torque at lower revs. As they're geared accordingly, this will not
give them better acceleration.

Want a torquey motor? Buy a Hayabusa, Blackbird or ZZR.

 

YM Triumph Rocket III.

 

"big bang" theory does disagree with Darsy's assertion.

Not much

Perhaps it's more to do with the throttle response? Dunno, to be
honest.